/* jshint esnext: true */
/* global assertEqual, assertTrue, fail, AQL_EXECUTE, AQL_EXPLAIN, AQL_EXECUTEJSON */

// //////////////////////////////////////////////////////////////////////////////
// / @brief Spec for the AQL FOR x IN GRAPH name statement
// /
// / @file
// /
// / DISCLAIMER
// /
// / Copyright 2014 ArangoDB GmbH, Cologne, Germany
// /
// / Licensed under the Apache License, Version 2.0 (the "License");
// / you may not use this file except in compliance with the License.
// / You may obtain a copy of the License at
// /
// /     http://www.apache.org/licenses/LICENSE-2.0
// /
// / Unless required by applicable law or agreed to in writing, software
// / distributed under the License is distributed on an "AS IS" BASIS,
// / WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// / See the License for the specific language governing permissions and
// / limitations under the License.
// /
// / Copyright holder is ArangoDB GmbH, Cologne, Germany
// /
// / @author Michael Hackstein
// / @author Copyright 2015, ArangoDB GmbH, Cologne, Germany
// //////////////////////////////////////////////////////////////////////////////

'use strict';

const jsunity = require('jsunity');

const internal = require('internal');
const db = internal.db;
const errors = require('@arangodb').errors;
const gm = require('@arangodb/general-graph');
const vn = 'UnitTestVertexCollection';
const en = 'UnitTestEdgeCollection';
const isCluster = require('@arangodb/cluster').isCluster();
const roundCost = require('@arangodb/aql-helper').roundCost;

var _ = require('lodash');
var vertex = {};
var edge = {};
var vc;
var ec;
var mmfilesEngine = (db._engine().name === 'mmfiles');

var cleanup = function () {
  db._drop(vn);
  db._drop(en);
  vertex = {};
  edge = {};
};

var createBaseGraph = function () {
  vc = db._create(vn, { numberOfShards: 4 });
  ec = db._createEdgeCollection(en, { numberOfShards: 4 });
  vertex.A = vc.save({ _key: 'A' })._id;
  vertex.B = vc.save({ _key: 'B' })._id;
  vertex.C = vc.save({ _key: 'C' })._id;
  vertex.D = vc.save({ _key: 'D' })._id;
  vertex.E = vc.save({ _key: 'E' })._id;
  vertex.F = vc.save({ _key: 'F' })._id;

  edge.AB = ec.save(vertex.A, vertex.B, {})._id;
  edge.BC = ec.save(vertex.B, vertex.C, {})._id;
  edge.CD = ec.save(vertex.C, vertex.D, {})._id;
  edge.CF = ec.save(vertex.C, vertex.F, {})._id;
  edge.EB = ec.save(vertex.E, vertex.B, {})._id;
  edge.FE = ec.save(vertex.F, vertex.E, {})._id;
};

function invalidStartVertexSuite() {
  const gn = 'UnitTestGraph';

  return {

    setUpAll: function () {
      db._drop(gn + 'v1');
      db._drop(gn + 'v2');
      db._drop(gn + 'e');

      let c;
      c = db._create(gn + 'v1', { numberOfShards: 1 });
      c.insert({ _key: "test" });

      c = db._create(gn + 'v2', { numberOfShards: 1 });
      c.insert({ _key: "test" });

      c = db._createEdgeCollection(gn + 'e', { numberOfShards: 1 });
      c.insert({ _from: gn + "v2/test", _to: gn + "v1/test" });
    },

    tearDownAll: function () {
      db._drop(gn + 'v1');
      db._drop(gn + 'v2');
      db._drop(gn + 'e');
    },
    
    testTraversalNullStartVertex: function () {
      let directions = ["INBOUND", "OUTBOUND", "ANY"];
      directions.forEach(function(direction) {
        try {
          let q = `WITH ${gn + 'v1'} ${gn + 'v2'} FOR v, e IN ${direction} null ${gn + 'e'} RETURN {v, e}`;
          AQL_EXECUTE(q);
          fail();
        } catch (err) {
          assertEqual(err.errorNum, errors.ERROR_QUERY_PARSE.code);
        }
      });
    },
    
    testTraversalNumberStartVertex: function () {
      let directions = ["INBOUND", "OUTBOUND", "ANY"];
      directions.forEach(function(direction) {
        let q = `WITH ${gn + 'v1'} ${gn + 'v2'} FOR v, e IN ${direction} -123 ${gn + 'e'} RETURN {v, e}`;
        try {
          AQL_EXECUTE(q);
          fail();
        } catch (err) {
          assertEqual(err.errorNum, errors.ERROR_QUERY_PARSE.code);
        }
      });
    },

    testTraversalEmptyStartVertex: function () {
      let directions = ["INBOUND", "OUTBOUND", "ANY"];
      directions.forEach(function(direction) {
        let q = `WITH ${gn + 'v1'} ${gn + 'v2'} FOR v, e IN ${direction} '' ${gn + 'e'} RETURN {v, e}`;
        let res = AQL_EXECUTE(q);
        assertEqual([], res.json);
        assertTrue(res.warnings.length > 0);
      });
    },
    
    testShortestPathNullStartVertex: function () {
      let directions = ["INBOUND", "OUTBOUND", "ANY"];
      directions.forEach(function(direction) {
        let q = `WITH ${gn + 'v1'} ${gn + 'v2'} FOR v, e IN ${direction} SHORTEST_PATH null TO '${vn + 'v1'}/1' ${gn + 'e'} RETURN {v, e}`;
        try {
          AQL_EXECUTE(q);
          fail();
        } catch (err) {
          assertEqual(err.errorNum, errors.ERROR_QUERY_PARSE.code);
        }
      });
    },
    
    testShortestPathNumberStartVertex: function () {
      let directions = ["INBOUND", "OUTBOUND", "ANY"];
      directions.forEach(function(direction) {
        let q = `WITH ${gn + 'v1'} ${gn + 'v2'} FOR v, e IN ${direction} SHORTEST_PATH -123 TO '${vn + 'v1'}/1' ${gn + 'e'} RETURN {v, e}`;
        try {
          AQL_EXECUTE(q);
          fail();
        } catch (err) {
          assertEqual(err.errorNum, errors.ERROR_QUERY_PARSE.code);
        }
      });
    },

    testShortestPathEmptyStartVertex: function () {
      let directions = ["INBOUND", "OUTBOUND", "ANY"];
      directions.forEach(function(direction) {
        let q = `WITH ${gn + 'v1'} ${gn + 'v2'} FOR v, e IN ${direction} SHORTEST_PATH '' TO '${vn + 'v1'}/1' ${gn + 'e'} RETURN {v, e}`;
        let res = AQL_EXECUTE(q);
        assertEqual([], res.json);
        assertTrue(res.warnings.length > 0);
      });
    },

    testShortestPathEmptyEndVertex: function () {
      let directions = ["INBOUND", "OUTBOUND", "ANY"];
      directions.forEach(function(direction) {
        let q = `WITH ${gn + 'v1'} ${gn + 'v2'} FOR v, e IN ${direction} SHORTEST_PATH '${vn + 'v1'}/1' TO '' ${gn + 'e'} RETURN {v, e}`;
        let res = AQL_EXECUTE(q);
        assertEqual([], res.json);
        assertTrue(res.warnings.length > 0);
      });
    },
    
    testShortestPathNullEndVertex: function () {
      let directions = ["INBOUND", "OUTBOUND", "ANY"];
      directions.forEach(function(direction) {
        let q = `WITH ${gn + 'v1'} ${gn + 'v2'} FOR v, e IN ${direction} SHORTEST_PATH '${vn + 'v1'}/1' TO null ${gn + 'e'} RETURN {v, e}`;
        try {
          AQL_EXECUTE(q);
          fail();
        } catch (err) {
          assertEqual(err.errorNum, errors.ERROR_QUERY_PARSE.code);
        }
      });
    },
    
    testShortestPathNumberEndVertex: function () {
      let directions = ["INBOUND", "OUTBOUND", "ANY"];
      directions.forEach(function(direction) {
        let q = `WITH ${gn + 'v1'} ${gn + 'v2'} FOR v, e IN ${direction} SHORTEST_PATH '${vn + 'v1'}/1' TO -123 ${gn + 'e'} RETURN {v, e}`;
        try {
          AQL_EXECUTE(q);
          fail();
        } catch (err) {
          assertEqual(err.errorNum, errors.ERROR_QUERY_PARSE.code);
        }
      });
    },

    testShortestPathBothEmpty: function () {
      let directions = ["INBOUND", "OUTBOUND", "ANY"];
      directions.forEach(function(direction) {
        let q = `WITH ${gn + 'v1'} ${gn + 'v2'} FOR v, e IN ${direction} SHORTEST_PATH '' TO '' ${gn + 'e'} RETURN {v, e}`;
        let res = AQL_EXECUTE(q);
        assertEqual([], res.json);
        assertTrue(res.warnings.length > 0);
      });
    },

    testKShortestPathsNullStartVertex: function () {
      let directions = ["INBOUND", "OUTBOUND", "ANY"];
      directions.forEach(function(direction) {
        let q = `WITH ${gn + 'v1'} ${gn + 'v2'} FOR v IN ${direction} K_SHORTEST_PATHS null TO '${vn + 'v1'}/1' ${gn + 'e'} RETURN v`;
        try {
          AQL_EXECUTE(q);
          fail();
        } catch (err) {
          assertEqual(err.errorNum, errors.ERROR_QUERY_PARSE.code);
        }
      });
    },
    
    testKShortestsPathNumberStartVertex: function () {
      let directions = ["INBOUND", "OUTBOUND", "ANY"];
      directions.forEach(function(direction) {
        let q = `WITH ${gn + 'v1'} ${gn + 'v2'} FOR v IN ${direction} K_SHORTEST_PATHS -123 TO '${vn + 'v1'}/1' ${gn + 'e'} RETURN v`;
        try {
          AQL_EXECUTE(q);
          fail();
        } catch (err) {
          assertEqual(err.errorNum, errors.ERROR_QUERY_PARSE.code);
        }
      });
    },

    testKShortestPathsEmptyStartVertex: function () {
      let directions = ["INBOUND", "OUTBOUND", "ANY"];
      directions.forEach(function(direction) {
        let q = `WITH ${gn + 'v1'} ${gn + 'v2'} FOR v IN ${direction} K_SHORTEST_PATHS '' TO '${vn + 'v1'}/1' ${gn + 'e'} RETURN v`;
        let res = AQL_EXECUTE(q);
        assertEqual([], res.json);
        assertTrue(res.warnings.length > 0);
      });
    },

    testKShortestPathsEmptyEndVertex: function () {
      let directions = ["INBOUND", "OUTBOUND", "ANY"];
      directions.forEach(function(direction) {
        let q = `WITH ${gn + 'v1'} ${gn + 'v2'} FOR v IN ${direction} K_SHORTEST_PATHS '${vn + 'v1'}/1' TO '' ${gn + 'e'} RETURN v`;
        let res = AQL_EXECUTE(q);
        assertEqual([], res.json);
        assertTrue(res.warnings.length > 0);
      });
    },
    
    testKShortestPathsNullEndVertex: function () {
      let directions = ["INBOUND", "OUTBOUND", "ANY"];
      directions.forEach(function(direction) {
        let q = `WITH ${gn + 'v1'} ${gn + 'v2'} FOR v IN ${direction} K_SHORTEST_PATHS '${vn + 'v1'}/1' TO null ${gn + 'e'} RETURN v`;
        try {
          AQL_EXECUTE(q);
          fail();
        } catch (err) {
          assertEqual(err.errorNum, errors.ERROR_QUERY_PARSE.code);
        }
      });
    },
    
    testKShortestPathsNumberEndVertex: function () {
      let directions = ["INBOUND", "OUTBOUND", "ANY"];
      directions.forEach(function(direction) {
        let q = `WITH ${gn + 'v1'} ${gn + 'v2'} FOR v IN ${direction} K_SHORTEST_PATHS '${vn + 'v1'}/1' TO -123 ${gn + 'e'} RETURN v`;
        try {
          AQL_EXECUTE(q);
          fail();
        } catch (err) {
          assertEqual(err.errorNum, errors.ERROR_QUERY_PARSE.code);
        }
      });
    },

    testKShortestPathsBothEmpty: function () {
      let directions = ["INBOUND", "OUTBOUND", "ANY"];
      directions.forEach(function(direction) {
        let q = `WITH ${gn + 'v1'} ${gn + 'v2'} FOR v IN ${direction} K_SHORTEST_PATHS '' TO '' ${gn + 'e'} RETURN v`;
        let res = AQL_EXECUTE(q);
        assertEqual([], res.json);
        assertTrue(res.warnings.length > 0);
      });
    }

  };
}

function simpleInboundOutboundSuite() {
  const gn = 'UnitTestGraph';

  return {

    setUp: function () {
      db._drop(gn + 'v1');
      db._drop(gn + 'v2');
      db._drop(gn + 'e');

      let c;
      c = db._create(gn + 'v1', { numberOfShards: 9 });
      c.insert({ _key: "test" });

      c = db._create(gn + 'v2', { numberOfShards: 7 });
      c.insert({ _key: "test" });

      c = db._createEdgeCollection(gn + 'e', { numberOfShards: 5 });
      c.insert({ _from: gn + "v2/test", _to: gn + "v1/test" });
    },

    tearDown: function () {
      db._drop(gn + 'v1');
      db._drop(gn + 'v2');
      db._drop(gn + 'e');
    },

    testTheOldInAndOutOut: function () {
      // outbound
      let q = `WITH ${gn + 'v1'} ${gn + 'v2'} FOR v, e IN OUTBOUND DOCUMENT("${gn + 'v2'}/test") ${gn + 'e'} RETURN {v, e}`;
      let res = AQL_EXECUTE(q).json[0];

      assertEqual(gn + "v1/test", res.v._id);
      assertEqual("test", res.v._key);
      assertEqual(gn + "v2/test", res.e._from);
      assertEqual(gn + "v1/test", res.e._to);

      // same test, but now reverse
      q = `WITH ${gn + 'v1'} ${gn + 'v2'} FOR v, e IN INBOUND DOCUMENT("${gn + 'v1'}/test") ${gn + 'e'} RETURN {v, e}`;
      res = AQL_EXECUTE(q).json[0];

      assertEqual(gn + "v2/test", res.v._id);
      assertEqual("test", res.v._key);
      assertEqual(gn + "v2/test", res.e._from);
      assertEqual(gn + "v1/test", res.e._to);
    }

  };
}

function limitSuite() {
  const gn = 'UnitTestGraph';

  return {

    setUpAll: function () {
      db._drop(gn + 'v');
      db._drop(gn + 'e');
      db._drop(gn + 'e2');

      var i;

      var c = db._create(gn + 'v');
      for (i = 0; i < 10000; ++i) {
        c.insert({ _key: 'test' + i });
      }

      c = db._createEdgeCollection(gn + 'e');
      for (i = 0; i < 10000; ++i) {
        c.insert({ _from: gn + 'v/test' + i, _to: gn + 'v/test' + i });
      }

      c = db._createEdgeCollection(gn + 'e2');
      c.insert({ _from: gn + 'v/test1', _to: gn + 'v/test0' });
      c.insert({ _from: gn + 'v/test2', _to: gn + 'v/test0' });
      c.insert({ _from: gn + 'v/test2', _to: gn + 'v/test1' });
    },

    tearDownAll: function () {
      db._drop(gn + 'v');
      db._drop(gn + 'e');
      db._drop(gn + 'e2');
    },

    testLimits: function () {
      const queries = [
        ['FOR v IN ' + gn + 'v FOR e IN 1..1 OUTBOUND v._id ' + gn + 'e LIMIT 0, 10000 RETURN e', 10000],
        ['FOR v IN ' + gn + 'v FOR e IN 1..1 OUTBOUND v._id ' + gn + 'e LIMIT 0, 1000 RETURN e', 1000],
        ['FOR v IN ' + gn + 'v FOR e IN 1..1 OUTBOUND v._id ' + gn + 'e LIMIT 0, 100 RETURN e', 100],
        ['FOR v IN ' + gn + 'v FOR e IN 1..1 OUTBOUND v._id ' + gn + 'e LIMIT 0, 10 RETURN e', 10],
        ['FOR v IN ' + gn + 'v FOR e IN 1..1 OUTBOUND v._id ' + gn + 'e LIMIT 10, 10 RETURN e', 10],
        ['FOR v IN ' + gn + 'v FOR e IN 1..1 OUTBOUND v._id ' + gn + 'e LIMIT 10, 100 RETURN e', 100],
        ['FOR v IN ' + gn + 'v FOR e IN 1..1 OUTBOUND v._id ' + gn + 'e LIMIT 10, 1000 RETURN e', 1000],
        ['FOR v IN ' + gn + 'v FOR e IN 1..1 OUTBOUND v._id ' + gn + 'e LIMIT 10, 10000 RETURN e', 9990],
        ['FOR v IN ' + gn + 'v FOR e IN 1..1 OUTBOUND v._id ' + gn + 'e LIMIT 1000, 1 RETURN e', 1],
        ['FOR v IN ' + gn + 'v FOR e IN 1..1 OUTBOUND v._id ' + gn + 'e LIMIT 1000, 10 RETURN e', 10],
        ['FOR v IN ' + gn + 'v FOR e IN 1..1 OUTBOUND v._id ' + gn + 'e LIMIT 1000, 100 RETURN e', 100],
        ['FOR v IN ' + gn + 'v FOR e IN 1..1 OUTBOUND v._id ' + gn + 'e LIMIT 1000, 1000 RETURN e', 1000],
        ['FOR v IN ' + gn + 'v FOR e IN 1..1 OUTBOUND v._id ' + gn + 'e LIMIT 1000, 10000 RETURN e', 9000],
        ['FOR v IN ' + gn + 'v FOR e IN 1..1 OUTBOUND v._id ' + gn + 'e LIMIT 9990, 1 RETURN e', 1],
        ['FOR v IN ' + gn + 'v FOR e IN 1..1 OUTBOUND v._id ' + gn + 'e LIMIT 9990, 9 RETURN e', 9],
        ['FOR v IN ' + gn + 'v FOR e IN 1..1 OUTBOUND v._id ' + gn + 'e LIMIT 9990, 10 RETURN e', 10],
        ['FOR v IN ' + gn + 'v FOR e IN 1..1 OUTBOUND v._id ' + gn + 'e LIMIT 9990, 11 RETURN e', 10],
        ['FOR v IN ' + gn + 'v FOR e IN 1..1 OUTBOUND v._id ' + gn + 'e LIMIT 9990, 100 RETURN e', 10],
        ['FOR v IN ' + gn + 'v FOR e IN 1..1 OUTBOUND v._id ' + gn + 'e LIMIT 9990, 1000 RETURN e', 10],
        ['FOR v IN ' + gn + 'v FOR e IN 1..1 OUTBOUND v._id ' + gn + 'e LIMIT 9999, 1 RETURN e', 1],
        ['FOR v IN ' + gn + 'v FOR e IN 1..1 OUTBOUND v._id ' + gn + 'e LIMIT 9999, 10 RETURN e', 1],
        ['FOR v IN ' + gn + 'v FOR e IN 1..1 OUTBOUND v._id ' + gn + 'e LIMIT 9999, 100 RETURN e', 1],
        ['FOR v IN ' + gn + 'v FOR e IN 1..1 OUTBOUND v._id ' + gn + 'e LIMIT 9999, 1000 RETURN e', 1],
        ['FOR v IN ' + gn + 'v FOR e IN 1..1 OUTBOUND v._id ' + gn + 'e LIMIT 10000, 0 RETURN e', 0],
        ['FOR v IN ' + gn + 'v FOR e IN 1..1 OUTBOUND v._id ' + gn + 'e LIMIT 10000, 1 RETURN e', 0],
        ['FOR v IN ' + gn + 'v FOR e IN 1..1 OUTBOUND v._id ' + gn + 'e LIMIT 10000, 10 RETURN e', 0],
        ['FOR v IN ' + gn + 'v FOR e IN 1..1 OUTBOUND v._id ' + gn + 'e LIMIT 10000, 1000 RETURN e', 0]
      ];

      queries.forEach(function (query) {
        assertEqual(query[1], AQL_EXECUTE(query[0]).json.length, query);
      });
    },

    testLimitsMultiEdges: function () {
      var queries = [
        ['WITH ' + gn + 'v FOR v IN ["' + gn + 'v/test0"] FOR e IN 1..1 OUTBOUND v ' + gn + 'e2 RETURN e', 0],
        ['WITH ' + gn + 'v FOR v IN ["' + gn + 'v/test0"] FOR e IN 1..1 OUTBOUND v ' + gn + 'e2 LIMIT 0, 1 RETURN e', 0],
        ['WITH ' + gn + 'v FOR v IN ["' + gn + 'v/test0"] FOR e IN 1..1 OUTBOUND v ' + gn + 'e2 LIMIT 1, 1 RETURN e', 0],
        ['WITH ' + gn + 'v FOR v IN ["' + gn + 'v/test1"] FOR e IN 1..1 OUTBOUND v ' + gn + 'e2 RETURN e', 1],
        ['WITH ' + gn + 'v FOR v IN ["' + gn + 'v/test1"] FOR e IN 1..1 OUTBOUND v ' + gn + 'e2 LIMIT 0, 1 RETURN e', 1],
        ['WITH ' + gn + 'v FOR v IN ["' + gn + 'v/test1"] FOR e IN 1..1 OUTBOUND v ' + gn + 'e2 LIMIT 1, 1 RETURN e', 0],
        ['WITH ' + gn + 'v FOR v IN ["' + gn + 'v/test1"] FOR e IN 1..1 OUTBOUND v ' + gn + 'e2 LIMIT 2, 1 RETURN e', 0],
        ['WITH ' + gn + 'v FOR v IN ["' + gn + 'v/test2"] FOR e IN 1..1 OUTBOUND v ' + gn + 'e2 RETURN e', 2],
        ['WITH ' + gn + 'v FOR v IN ["' + gn + 'v/test2"] FOR e IN 1..1 OUTBOUND v ' + gn + 'e2 LIMIT 0, 1 RETURN e', 1],
        ['WITH ' + gn + 'v FOR v IN ["' + gn + 'v/test2"] FOR e IN 1..1 OUTBOUND v ' + gn + 'e2 LIMIT 0, 1 RETURN e', 1],
        ['WITH ' + gn + 'v FOR v IN ["' + gn + 'v/test2"] FOR e IN 1..1 OUTBOUND v ' + gn + 'e2 LIMIT 0, 2 RETURN e', 2],
        ['WITH ' + gn + 'v FOR v IN ["' + gn + 'v/test2"] FOR e IN 1..1 OUTBOUND v ' + gn + 'e2 LIMIT 1, 1 RETURN e', 1],
        ['WITH ' + gn + 'v FOR v IN ["' + gn + 'v/test2"] FOR e IN 1..1 OUTBOUND v ' + gn + 'e2 LIMIT 1, 2 RETURN e', 1],
        ['WITH ' + gn + 'v FOR v IN ["' + gn + 'v/test2"] FOR e IN 1..1 OUTBOUND v ' + gn + 'e2 LIMIT 2, 1 RETURN e', 0]
      ];

      queries.forEach(function (query) {
        assertEqual(query[1], AQL_EXECUTE(query[0]).json.length, query);
      });
    }

  };
}

function nestedSuite() {
  const gn = 'UnitTestGraph';
  var objects, tags, tagged;

  return {

    setUpAll: function () {
      tags = db._create(gn + 'tags');
      objects = db._create(gn + 'objects');
      tagged = db._createEdgeCollection(gn + 'tagged');

      ['airplane', 'bicycle', 'train', 'car', 'boat'].forEach(function (_key) {
        objects.insert({ _key });
      });

      ['public', 'private', 'fast', 'slow', 'land', 'air', 'water'].forEach(function (_key) {
        tags.insert({ _key });
      });

      [
        ['air', 'airplane'],
        ['land', 'car'],
        ['land', 'bicycle'],
        ['land', 'train'],
        ['water', 'boat'],
        ['fast', 'airplane'],
        ['fast', 'car'],
        ['slow', 'bicycle'],
        ['fast', 'train'],
        ['slow', 'boat'],
        ['public', 'airplane'],
        ['private', 'car'],
        ['private', 'bicycle'],
        ['public', 'train'],
        ['public', 'boat']
      ].forEach(function (edge) {
        tagged.insert({ _from: tags.name() + '/' + edge[0], _to: objects.name() + '/' + edge[1] });
      });
    },

    tearDownAll: function () {
      db._drop(gn + 'tags');
      db._drop(gn + 'objects');
      db._drop(gn + 'tagged');
    },

    testNested: function () {
      var query = 'with ' + objects.name() + ', ' + tags.name() + ' for vehicle in any @start1 @@tagged for type in any @start2 @@tagged filter vehicle._id == type._id return vehicle._key';

      var result = AQL_EXECUTE(query, { start1: tags.name() + '/land', start2: tags.name() + '/public', '@tagged': tagged.name() }).json;
      assertEqual(['train'], result);

      result = AQL_EXECUTE(query, { start1: tags.name() + '/air', start2: tags.name() + '/fast', '@tagged': tagged.name() }).json;
      assertEqual(['airplane'], result);

      result = AQL_EXECUTE(query, { start1: tags.name() + '/air', start2: tags.name() + '/slow', '@tagged': tagged.name() }).json;
      assertEqual([], result);

      result = AQL_EXECUTE(query, { start1: tags.name() + '/land', start2: tags.name() + '/fast', '@tagged': tagged.name() }).json;
      assertEqual(['car', 'train'], result.sort());

      result = AQL_EXECUTE(query, { start1: tags.name() + '/land', start2: tags.name() + '/private', '@tagged': tagged.name() }).json;
      assertEqual(['bicycle', 'car'], result.sort());

      result = AQL_EXECUTE(query, { start1: tags.name() + '/public', start2: tags.name() + '/slow', '@tagged': tagged.name() }).json;
      assertEqual(['boat'], result);

      result = AQL_EXECUTE(query, { start1: tags.name() + '/public', start2: tags.name() + '/fast', '@tagged': tagged.name() }).json;
      assertEqual(['airplane', 'train'], result.sort());

      result = AQL_EXECUTE(query, { start1: tags.name() + '/public', start2: tags.name() + '/foo', '@tagged': tagged.name() }).json;
      assertEqual([], result);

      result = AQL_EXECUTE(query, { start1: tags.name() + '/foo', start2: tags.name() + '/fast', '@tagged': tagged.name() }).json;
      assertEqual([], result);
    }
  };
}

function namedGraphSuite() {
  /* *********************************************************************
   * Graph under test:
   *
   *  A -> B  ->  C -> D
   *      /|\    \|/
   *       E  <-  F
   *
   ***********************************************************************/
  const gn = 'UnitTestGraph';
  var ruleName = 'optimize-traversals';
  var paramEnabled = { optimizer: { rules: ['-all', '+' + ruleName] } };
  var opts = _.clone(paramEnabled);

  return {

    setUpAll: function () {
      opts.allPlans = true;
      opts.verbosePlans = true;
      cleanup();
      createBaseGraph();
      try {
        gm._drop(gn);
      } catch (e) {
        // It is expected that this graph does not exist.
      }
      gm._create(gn, [gm._relation(en, vn, vn)]);
    },

    tearDownAll: function () {
      gm._drop(gn);
      cleanup();
    },

    testNamedFirstEntryIsVertex: function () {
      var query = 'FOR x IN OUTBOUND @startId GRAPH @graph RETURN x';
      var bindVars = {
        graph: gn,
        startId: vertex.B
      };
      var result = db._query(query, bindVars).toArray();
      assertEqual(result.length, 1);
      assertEqual(result[0]._id, vertex.C);
      var plans = AQL_EXPLAIN(query, bindVars, opts).plans;
      plans.forEach(function (plan) {
        var jsonResult = AQL_EXECUTEJSON(plan, { optimizer: { rules: ['-all'] } }).json;
        assertEqual(jsonResult, result, query);
      });
    },

    testNamedSecondEntryIsEdge: function () {
      var query = 'FOR x, e IN OUTBOUND @startId GRAPH @graph RETURN e';
      var bindVars = {
        graph: gn,
        startId: vertex.B
      };
      var result = db._query(query, bindVars).toArray();
      assertEqual(result.length, 1);
      assertEqual(result[0]._id, edge.BC);
      var plans = AQL_EXPLAIN(query, bindVars, opts).plans;
      plans.forEach(function (plan) {
        var jsonResult = AQL_EXECUTEJSON(plan, { optimizer: { rules: ['-all'] } }).json;
        assertEqual(jsonResult, result, query);
      });
    },

    testNamedThirdEntryIsPath: function () {
      var query = 'FOR x, e, p IN OUTBOUND @startId GRAPH @graph RETURN p';
      var bindVars = {
        graph: gn,
        startId: vertex.B
      };
      var result = db._query(query, bindVars).toArray();
      assertEqual(result.length, 1);
      var entry = result[0];
      assertEqual(entry.vertices.length, 2);
      assertEqual(entry.vertices[0]._id, vertex.B);
      assertEqual(entry.vertices[1]._id, vertex.C);
      assertEqual(entry.edges.length, 1);
      assertEqual(entry.edges[0]._id, edge.BC);
      var plans = AQL_EXPLAIN(query, bindVars, opts).plans;
      plans.forEach(function (plan) {
        var jsonResult = AQL_EXECUTEJSON(plan, { optimizer: { rules: ['-all'] } }).json;
        assertEqual(jsonResult, result, query);
      });
    },

    testNamedOutboundDirection: function () {
      var query = 'FOR x IN OUTBOUND @startId GRAPH @graph RETURN x._id';
      var bindVars = {
        graph: gn,
        startId: vertex.B
      };
      var result = db._query(query, bindVars).toArray();
      assertEqual(result.length, 1);
      var entry = result[0];
      assertEqual(entry, vertex.C);
      var plans = AQL_EXPLAIN(query, bindVars, opts).plans;
      plans.forEach(function (plan) {
        var jsonResult = AQL_EXECUTEJSON(plan, { optimizer: { rules: ['-all'] } }).json;
        assertEqual(jsonResult, result, query);
      });
    },

    testNamedInboundDirection: function () {
      var query = 'FOR x IN INBOUND @startId GRAPH @graph RETURN x._id';
      var bindVars = {
        graph: gn,
        startId: vertex.C
      };
      var result = db._query(query, bindVars).toArray();
      assertEqual(result.length, 1);
      var entry = result[0];
      assertEqual(entry, vertex.B);
      var plans = AQL_EXPLAIN(query, bindVars, opts).plans;
      plans.forEach(function (plan) {
        var jsonResult = AQL_EXECUTEJSON(plan, { optimizer: { rules: ['-all'] } }).json;
        assertEqual(jsonResult, result, query);
      });
    },

    testNamedAnyDirection: function () {
      var query = 'FOR x IN ANY @startId GRAPH @graph SORT x._id ASC RETURN x._id';
      var bindVars = {
        graph: gn,
        startId: vertex.B
      };
      var result = db._query(query, bindVars).toArray();
      assertEqual(result.length, 3);
      var entry = result[0];
      assertEqual(entry, vertex.A);
      entry = result[1];
      assertEqual(entry, vertex.C);
      entry = result[2];
      assertEqual(entry, vertex.E);
      var plans = AQL_EXPLAIN(query, bindVars, opts).plans;
      plans.forEach(function (plan) {
        var jsonResult = AQL_EXECUTEJSON(plan, { optimizer: { rules: ['-all'] } }).json;
        assertEqual(jsonResult, result, query);
      });
    },

    testNamedExactNumberSteps: function () {
      var query = 'FOR x IN 2 OUTBOUND @startId GRAPH @graph SORT x._id ASC RETURN x._id';
      var bindVars = {
        graph: gn,
        startId: vertex.B
      };
      var result = db._query(query, bindVars).toArray();
      assertEqual(result.length, 2);

      assertEqual(result[0], vertex.D);
      assertEqual(result[1], vertex.F);
      var plans = AQL_EXPLAIN(query, bindVars, opts).plans;
      plans.forEach(function (plan) {
        var jsonResult = AQL_EXECUTEJSON(plan, { optimizer: { rules: ['-all'] } }).json;
        assertEqual(jsonResult, result, query);
      });
    },

    testNamedRangeNumberSteps: function () {
      var query = 'FOR x IN 2..3 OUTBOUND @startId GRAPH @graph SORT x._id ASC RETURN x._id';
      var bindVars = {
        graph: gn,
        startId: vertex.B
      };
      var result = db._query(query, bindVars).toArray();
      assertEqual(result.length, 3);

      assertEqual(result[0], vertex.D);
      assertEqual(result[1], vertex.E);
      assertEqual(result[2], vertex.F);
      var plans = AQL_EXPLAIN(query, bindVars, opts).plans;
      plans.forEach(function (plan) {
        var jsonResult = AQL_EXECUTEJSON(plan, { optimizer: { rules: ['-all'] } }).json;
        assertEqual(jsonResult, result, query);
      });
    },

    testNamedComputedNumberSteps: function () {
      var query = 'FOR x IN LENGTH([1,2]) OUTBOUND @startId GRAPH @graph SORT x._id ASC RETURN x._id';
      var bindVars = {
        graph: gn,
        startId: vertex.B
      };
      var result = db._query(query, bindVars).toArray();
      assertEqual(result.length, 2);

      assertEqual(result[0], vertex.D);
      var plans = AQL_EXPLAIN(query, bindVars, opts).plans;
      plans.forEach(function (plan) {
        var jsonResult = AQL_EXECUTEJSON(plan, { optimizer: { rules: ['-all'] } }).json;
        assertEqual(jsonResult, result, query);
      });
    },

    testNamedZeroSteps: function () {
      // We only include the start vertex
      var query = 'FOR x IN 0 OUTBOUND @startId GRAPH @graph SORT x._id ASC RETURN x._id';
      var bindVars = {
        graph: gn,
        startId: vertex.B
      };
      var result = db._query(query, bindVars).toArray();
      assertEqual(result.length, 1);
      assertEqual(result[0], vertex.B);
      var plans = AQL_EXPLAIN(query, bindVars, opts).plans;
      plans.forEach(function (plan) {
        var jsonResult = AQL_EXECUTEJSON(plan, { optimizer: { rules: ['-all'] } }).json;
        assertEqual(jsonResult, result, query);
      });
    },

    testNamedZeroStartRangeSteps: function () {
      // We only include the start vertex
      var query = 'FOR x IN 0..1 OUTBOUND @startId GRAPH @graph SORT x._id ASC RETURN x._id';
      var bindVars = {
        graph: gn,
        startId: vertex.B
      };
      var result = db._query(query, bindVars).toArray();
      assertEqual(result.length, 2);
      assertEqual(result[0], vertex.B);
      assertEqual(result[1], vertex.C);
      var plans = AQL_EXPLAIN(query, bindVars, opts).plans;
      plans.forEach(function (plan) {
        var jsonResult = AQL_EXECUTEJSON(plan, { optimizer: { rules: ['-all'] } }).json;
        assertEqual(jsonResult, result, query);
      });
    },

    testNamedSort: function () {
      var query = 'FOR x IN OUTBOUND @startId GRAPH @graph SORT x._id ASC RETURN x._id';
      var bindVars = {
        graph: gn,
        startId: vertex.C
      };

      var result = db._query(query, bindVars).toArray();
      assertEqual(result.length, 2);
      assertEqual(result[0], vertex.D);
      assertEqual(result[1], vertex.F);

      // Reverse ordering
      query = 'FOR x IN OUTBOUND @startId GRAPH @graph SORT x._id DESC RETURN x._id';

      result = db._query(query, bindVars).toArray();
      assertEqual(result.length, 2);
      assertEqual(result[0], vertex.F);
      assertEqual(result[1], vertex.D);

      var plans = AQL_EXPLAIN(query, bindVars, opts).plans;
      plans.forEach(function (plan) {
        var jsonResult = AQL_EXECUTEJSON(plan, { optimizer: { rules: ['-all'] } }).json;
        assertEqual(jsonResult, result, query);
      });
    },

    testNamedUniqueEdgesOnPath: function () {
      var query = 'FOR x IN 6 OUTBOUND @startId GRAPH @graph RETURN x._id';
      var bindVars = {
        graph: gn,
        startId: vertex.A
      };
      // No result A->B->C->F->E->B (->C) is already used!
      var result = db._query(query, bindVars).toArray();
      assertEqual(result.length, 0);

      query = 'FOR x, e, p IN 2 ANY @startId GRAPH @graph SORT x._id ASC ' +
        'RETURN {v: x._id, edges: p.edges, vertices: p.vertices}';
      result = db._query(query, bindVars).toArray();

      // result: A->B->C
      // result: A->B<-E
      // Invalid result: A->B<-A
      assertEqual(result.length, 2);
      assertEqual(result[0].v, vertex.C);
      assertEqual(result[0].edges.length, 2);
      assertEqual(result[0].edges[0]._id, edge.AB);
      assertEqual(result[0].edges[1]._id, edge.BC);

      assertEqual(result[0].vertices.length, 3);
      assertEqual(result[0].vertices[0]._id, vertex.A);
      assertEqual(result[0].vertices[1]._id, vertex.B);
      assertEqual(result[0].vertices[2]._id, vertex.C);
      assertEqual(result[1].v, vertex.E);
      assertEqual(result[1].edges.length, 2);
      assertEqual(result[1].edges[0]._id, edge.AB);
      assertEqual(result[1].edges[1]._id, edge.EB);

      assertEqual(result[1].vertices.length, 3);
      assertEqual(result[1].vertices[0]._id, vertex.A);
      assertEqual(result[1].vertices[1]._id, vertex.B);
      assertEqual(result[1].vertices[2]._id, vertex.E);

      query = `FOR x IN 1 ANY @startId GRAPH @graph
      FOR y IN 1 ANY x GRAPH @graph
      SORT y._id ASC RETURN y._id`;
      result = db._query(query, bindVars).toArray();

      // result: A->B<-A
      // result: A->B->C
      // result: A->B<-E
      // The second traversal resets the path
      assertEqual(result.length, 3);
      assertEqual(result[0], vertex.A);
      assertEqual(result[1], vertex.C);
      assertEqual(result[2], vertex.E);
    }
  };
}

function multiCollectionGraphSuite() {
  /* *********************************************************************
   * Graph under test:
   *
   *  A -> B -> C -> D <-E2- V2:G
   *      /|\  \|/
   *       E <- F
   *
   ***********************************************************************/
  const gn = 'UnitTestGraph';
  const vn2 = 'UnitTestVertexCollection2';
  const en2 = 'UnitTestEdgeCollection2';
  var ruleName = 'optimize-traversals';
  var paramEnabled = { optimizer: { rules: ['-all', '+' + ruleName] } };
  var opts = _.clone(paramEnabled);

  // We always use the same query, the result should be identical.
  var validateResult = function (result) {
    assertEqual(result.length, 1);
    var entry = result[0];
    assertEqual(entry.vertex._id, vertex.C);
    assertEqual(entry.path.vertices.length, 2);
    assertEqual(entry.path.vertices[0]._id, vertex.B);
    assertEqual(entry.path.vertices[1]._id, vertex.C);
    assertEqual(entry.path.edges.length, 1);
    assertEqual(entry.path.edges[0]._id, edge.BC);
  };

  return {

    setUpAll: function () {
      opts.allPlans = true;
      opts.verbosePlans = true;
      cleanup();
      try {
        gm._drop(gn);
      } catch (e) {
        // It is expected that this graph does not exist.
      }
      db._drop(vn2);
      db._drop(en2);
      createBaseGraph();
      gm._create(gn, [gm._relation(en, vn, vn), gm._relation(en2, vn2, vn)]);
      db[vn2].save({ _key: 'G' });
      db[en2].save(vn2 + '/G', vn + '/D', {});
    },

    tearDownAll: function () {
      gm._drop(gn);
      db._drop(vn2);
      db._drop(en2);
      cleanup();
    },

    testNoBindParameterDoubleFor: function () {
      /* this test is intended to trigger the clone functionality. */
      var query = 'FOR t IN ' + vn +
        ' FOR s IN ' + vn2 +
        ' FOR x, e, p IN OUTBOUND t ' + en + ' SORT x._key RETURN {vertex: x, path: p}';
      var result = db._query(query).toArray();
      var plans = AQL_EXPLAIN(query, {}, opts).plans;
      plans.forEach(function (plan) {
        var jsonResult = AQL_EXECUTEJSON(plan, { optimizer: { rules: ['-all'] } }).json;
        assertEqual(jsonResult, result, query);
      });
    },

    testNoBindParameterSingleFor: function () {
      var query = 'FOR s IN ' + vn + ' FOR x, e, p IN OUTBOUND s ' + en + ' SORT x._key RETURN x';
      var result = db._query(query).toArray();
      var plans = AQL_EXPLAIN(query, {}, opts).plans;
      plans.forEach(function (plan) {
        var jsonResult = AQL_EXECUTEJSON(plan, { optimizer: { rules: ['-all'] } }).json;
        assertEqual(jsonResult, result, query);
      });
    },

    testNoBindParameterSingleForFilter: function () {
      var query = 'FOR s IN ' + vn + ' FOR x, e, p IN OUTBOUND s ' +
        en + ' FILTER p.vertices[1]._key == s._key SORT x._key RETURN x';
      var result = db._query(query).toArray();
      assertEqual(result.length, 0);
      var plans = AQL_EXPLAIN(query, {}, opts).plans;
      plans.forEach(function (plan) {
        var jsonResult = AQL_EXECUTEJSON(plan, { optimizer: { rules: ['-all'] } }).json;
        assertEqual(jsonResult.length, 0);
      });
    },

    testNoBindParameterRandFunction: function () {
      var query = 'FOR s IN ' + vn + ' FOR x, e, p IN OUTBOUND s ' +
        en + ' FILTER p.vertices[1]._key == NOOPT(RAND()) SORT x._key RETURN x';
      var result = db._query(query).toArray();
      assertEqual(result.length, 0);
      var plans = AQL_EXPLAIN(query, {}, opts).plans;
      plans.forEach(function (plan) {
        var jsonResult = AQL_EXECUTEJSON(plan, { optimizer: { rules: ['-all'] } }).json;
        assertEqual(jsonResult.length, 0);
      });
    },

    testNoBindParameter: function () {
      var query = `WITH ${vn}
      FOR x, e, p IN OUTBOUND '${vertex.B}' ${en}
      SORT x._key
      RETURN {vertex: x, path: p}`;
      var result = db._query(query).toArray();
      validateResult(result);
      var plans = AQL_EXPLAIN(query, {}, opts).plans;
      plans.forEach(function (plan) {
        var jsonResult = AQL_EXECUTEJSON(plan, { optimizer: { rules: ['-all'] } }).json;
        assertEqual(jsonResult, result, query);
      });
    },

    testStartBindParameter: function () {
      var query = `WITH ${vn}
      FOR x, e, p IN OUTBOUND @startId ${en}
      SORT x._key
      RETURN {vertex: x, path: p}`;
      var bindVars = {
        startId: vertex.B
      };
      var result = db._query(query, bindVars).toArray();
      validateResult(result);
      var plans = AQL_EXPLAIN(query, bindVars, opts).plans;
      plans.forEach(function (plan) {
        var jsonResult = AQL_EXECUTEJSON(plan, { optimizer: { rules: ['-all'] } }).json;
        assertEqual(jsonResult, result, query);
      });
    },

    testEdgeCollectionBindParameter: function () {
      var query = `WITH ${vn}
      FOR x, e, p IN OUTBOUND '${vertex.B}' @@eCol
      SORT x._key
      RETURN {vertex: x, path: p}`;
      var bindVars = {
        '@eCol': en
      };
      var result = db._query(query, bindVars).toArray();
      validateResult(result);
      var plans = AQL_EXPLAIN(query, bindVars, opts).plans;
      plans.forEach(function (plan) {
        var jsonResult = AQL_EXECUTEJSON(plan, { optimizer: { rules: ['-all'] } }).json;
        assertEqual(jsonResult, result, query);
      });
    },

    testStepsBindParameter: function () {
      var query = `WITH ${vn}
      FOR x, e, p IN @steps OUTBOUND '${vertex.B}' ${en}
      SORT x._key
      RETURN {vertex: x, path: p}`;
      var bindVars = {
        steps: 1
      };
      var result = db._query(query, bindVars).toArray();
      validateResult(result);
      var plans = AQL_EXPLAIN(query, bindVars, opts).plans;
      plans.forEach(function (plan) {
        var jsonResult = AQL_EXECUTEJSON(plan, { optimizer: { rules: ['-all'] } }).json;
        assertEqual(jsonResult, result, query);
      });
    },

    testStepsRangeBindParameter: function () {
      var query = `WITH ${vn}
      FOR x, e, p IN @lsteps..@rsteps OUTBOUND '${vertex.B}' ${en}
      SORT x._key
      RETURN {vertex: x, path: p}`;
      var bindVars = {
        lsteps: 1,
        rsteps: 1
      };
      var result = db._query(query, bindVars).toArray();
      validateResult(result);
      var plans = AQL_EXPLAIN(query, bindVars, opts).plans;
      plans.forEach(function (plan) {
        var jsonResult = AQL_EXECUTEJSON(plan, { optimizer: { rules: ['-all'] } }).json;
        assertEqual(jsonResult, result, query);
      });
    },

    testFirstEntryIsVertex: function () {
      var query = `WITH ${vn}
      FOR x IN OUTBOUND @startId @@eCol
      SORT x._key
      RETURN x`;
      var bindVars = {
        '@eCol': en,
        startId: vertex.B
      };
      var result = db._query(query, bindVars).toArray();
      assertEqual(result.length, 1);
      assertEqual(result[0]._id, vertex.C);
      var plans = AQL_EXPLAIN(query, bindVars, opts).plans;
      plans.forEach(function (plan) {
        var jsonResult = AQL_EXECUTEJSON(plan, { optimizer: { rules: ['-all'] } }).json;
        assertEqual(jsonResult, result, query);
      });
    },

    testSecondEntryIsEdge: function () {
      var query = `WITH ${vn}
      FOR x, e IN OUTBOUND @startId @@eCol
      SORT x._key
      RETURN e`;
      var bindVars = {
        '@eCol': en,
        startId: vertex.B
      };
      var result = db._query(query, bindVars).toArray();
      assertEqual(result.length, 1);
      assertEqual(result[0]._id, edge.BC);
      var plans = AQL_EXPLAIN(query, bindVars, opts).plans;
      plans.forEach(function (plan) {
        var jsonResult = AQL_EXECUTEJSON(plan, { optimizer: { rules: ['-all'] } }).json;
        assertEqual(jsonResult, result, query);
      });
    },

    testThirdEntryIsPath: function () {
      var query = `WITH ${vn}
      FOR x, e, p IN OUTBOUND @startId @@eCol
      SORT x._key
      RETURN p`;
      var bindVars = {
        '@eCol': en,
        startId: vertex.B
      };
      var result = db._query(query, bindVars).toArray();
      assertEqual(result.length, 1);
      var entry = result[0];
      assertEqual(entry.vertices.length, 2);
      assertEqual(entry.vertices[0]._id, vertex.B);
      assertEqual(entry.vertices[1]._id, vertex.C);
      assertEqual(entry.edges.length, 1);
      assertEqual(entry.edges[0]._id, edge.BC);
      var plans = AQL_EXPLAIN(query, bindVars, opts).plans;
      plans.forEach(function (plan) {
        var jsonResult = AQL_EXECUTEJSON(plan, { optimizer: { rules: ['-all'] } }).json;
        assertEqual(jsonResult, result, query);
      });
    },

    testOutboundDirection: function () {
      var query = `WITH ${vn}
      FOR x IN OUTBOUND @startId @@eCol
      SORT x._key
      RETURN x._id`;
      var bindVars = {
        '@eCol': en,
        startId: vertex.B
      };
      var result = db._query(query, bindVars).toArray();
      assertEqual(result.length, 1);
      var entry = result[0];
      assertEqual(entry, vertex.C);
      var plans = AQL_EXPLAIN(query, bindVars, opts).plans;
      plans.forEach(function (plan) {
        var jsonResult = AQL_EXECUTEJSON(plan, { optimizer: { rules: ['-all'] } }).json;
        assertEqual(jsonResult, result, query);
      });
    },

    testInboundDirection: function () {
      var query = `WITH ${vn}
      FOR x IN INBOUND @startId @@eCol
      SORT x._key
      RETURN x._id`;
      var bindVars = {
        '@eCol': en,
        startId: vertex.C
      };
      var result = db._query(query, bindVars).toArray();
      assertEqual(result.length, 1);
      var entry = result[0];
      assertEqual(entry, vertex.B);
      var plans = AQL_EXPLAIN(query, bindVars, opts).plans;
      plans.forEach(function (plan) {
        var jsonResult = AQL_EXECUTEJSON(plan, { optimizer: { rules: ['-all'] } }).json;
        assertEqual(jsonResult, result, query);
      });
    },

    testAnyDirection: function () {
      var query = `WITH ${vn}
      FOR x IN ANY @startId @@eCol
      SORT x._id ASC
      RETURN x._id`;
      var bindVars = {
        '@eCol': en,
        startId: vertex.B
      };
      var result = db._query(query, bindVars).toArray();
      assertEqual(result.length, 3);
      var entry = result[0];
      assertEqual(entry, vertex.A);
      entry = result[1];
      assertEqual(entry, vertex.C);
      entry = result[2];
      assertEqual(entry, vertex.E);
      var plans = AQL_EXPLAIN(query, bindVars, opts).plans;
      plans.forEach(function (plan) {
        var jsonResult = AQL_EXECUTEJSON(plan, { optimizer: { rules: ['-all'] } }).json;
        assertEqual(jsonResult, result, query);
      });
    },

    testExactNumberSteps: function () {
      var query = `WITH ${vn}
      FOR x IN 2 OUTBOUND @startId @@eCol
      SORT x._id ASC
      RETURN x._id`;
      var bindVars = {
        '@eCol': en,
        startId: vertex.B
      };
      var result = db._query(query, bindVars).toArray();
      assertEqual(result.length, 2);

      assertEqual(result[0], vertex.D);
      assertEqual(result[1], vertex.F);
      var plans = AQL_EXPLAIN(query, bindVars, opts).plans;
      plans.forEach(function (plan) {
        var jsonResult = AQL_EXECUTEJSON(plan, { optimizer: { rules: ['-all'] } }).json;
        assertEqual(jsonResult, result, query);
      });
    },

    testRangeNumberSteps: function () {
      var query = `WITH ${vn}
      FOR x IN 2..3 OUTBOUND @startId @@eCol
      SORT x._id ASC
      RETURN x._id`;
      var bindVars = {
        '@eCol': en,
        startId: vertex.B
      };
      var result = db._query(query, bindVars).toArray();
      assertEqual(result.length, 3);

      assertEqual(result[0], vertex.D);
      assertEqual(result[1], vertex.E);
      assertEqual(result[2], vertex.F);
      var plans = AQL_EXPLAIN(query, bindVars, opts).plans;
      plans.forEach(function (plan) {
        var jsonResult = AQL_EXECUTEJSON(plan, { optimizer: { rules: ['-all'] } }).json;
        assertEqual(jsonResult, result, query);
      });
    },

    testComputedNumberSteps: function () {
      var query = `WITH ${vn}
      FOR x IN LENGTH([1,2]) OUTBOUND @startId @@eCol
      SORT x._id ASC
      RETURN x._id`;
      var bindVars = {
        '@eCol': en,
        startId: vertex.B
      };
      var result = db._query(query, bindVars).toArray();
      assertEqual(result.length, 2);

      assertEqual(result[0], vertex.D);
      var plans = AQL_EXPLAIN(query, bindVars, opts).plans;
      plans.forEach(function (plan) {
        var jsonResult = AQL_EXECUTEJSON(plan, { optimizer: { rules: ['-all'] } }).json;
        assertEqual(jsonResult, result, query);
      });
    },

    testSort: function () {
      var query = `WITH ${vn}
      FOR x IN OUTBOUND @startId @@eCol
      SORT x._id ASC
      RETURN x._id`;
      var bindVars = {
        '@eCol': en,
        startId: vertex.C
      };

      var result = db._query(query, bindVars).toArray();
      assertEqual(result.length, 2);
      assertEqual(result[0], vertex.D);
      assertEqual(result[1], vertex.F);

      // Reverse ordering
      query = `WITH ${vn}
      FOR x IN OUTBOUND @startId @@eCol
      SORT x._id DESC
      RETURN x._id`;

      result = db._query(query, bindVars).toArray();
      assertEqual(result.length, 2);
      assertEqual(result[0], vertex.F);
      assertEqual(result[1], vertex.D);
      var plans = AQL_EXPLAIN(query, bindVars, opts).plans;
      plans.forEach(function (plan) {
        var jsonResult = AQL_EXECUTEJSON(plan, { optimizer: { rules: ['-all'] } }).json;
        assertEqual(jsonResult, result, query);
      });
    },

    testSingleDocumentInput: function () {
      var query = `FOR y IN @@vCol FILTER y._id == @startId
          FOR x IN OUTBOUND y @@eCol SORT x._key RETURN x`;
      var bindVars = {
        startId: vertex.B,
        '@eCol': en,
        '@vCol': vn
      };
      var result = db._query(query, bindVars).toArray();
      assertEqual(result.length, 1);
      assertEqual(result[0]._id, vertex.C);
      var plans = AQL_EXPLAIN(query, bindVars, opts).plans;
      plans.forEach(function (plan) {
        var jsonResult = AQL_EXECUTEJSON(plan, { optimizer: { rules: ['-all'] } }).json;
        assertEqual(jsonResult, result, query);
      });
    },

    testListDocumentInput: function () {
      var query = `WITH ${vn}
      FOR y IN @@vCol
      FOR x IN OUTBOUND y @@eCol
      SORT x._id ASC
      RETURN x._id`;
      var bindVars = {
        '@eCol': en,
        '@vCol': vn
      };
      var result = db._query(query, bindVars).toArray();
      assertEqual(result.length, 6);
      assertEqual(result[0], vertex.B);
      assertEqual(result[1], vertex.B);
      assertEqual(result[2], vertex.C);
      assertEqual(result[3], vertex.D);
      assertEqual(result[4], vertex.E);
      assertEqual(result[5], vertex.F);
      var plans = AQL_EXPLAIN(query, bindVars, opts).plans;
      plans.forEach(function (plan) {
        var jsonResult = AQL_EXECUTEJSON(plan, { optimizer: { rules: ['-all'] } }).json;
        assertEqual(jsonResult, result, query);
      });
    },

    testOtherCollectionAttributeAccessInput: function () {
      var query = `WITH ${vn}
      FOR y IN @@vCol
      FOR x IN OUTBOUND y._id @@eCol
      SORT x._id ASC
      RETURN x._id`;
      var bindVars = {
        '@eCol': en,
        '@vCol': vn
      };
      var result = db._query(query, bindVars).toArray();
      assertEqual(result.length, 6);
      assertEqual(result[0], vertex.B);
      assertEqual(result[1], vertex.B);
      assertEqual(result[2], vertex.C);
      assertEqual(result[3], vertex.D);
      assertEqual(result[4], vertex.E);
      assertEqual(result[5], vertex.F);
    },

    testTraversalAttributeAccessInput: function () {
      var query = `WITH ${vn}
      FOR x IN OUTBOUND @startId @@eCol
      FOR y IN OUTBOUND x._id @@eCol
      SORT y._id ASC
      RETURN y._id`;
      var bindVars = {
        '@eCol': en,
        'startId': vertex.A
      };
      var result = db._query(query, bindVars).toArray();
      assertEqual(result.length, 1);
      assertEqual(result[0], vertex.C);
    },

    testTraversalLetIdInput: function () {
      var query = `WITH ${vn}
      FOR x IN OUTBOUND @startId @@eCol
      LET next = x._id
      FOR y IN OUTBOUND next @@eCol
      SORT y._id ASC
      RETURN y._id`;
      var bindVars = {
        '@eCol': en,
        'startId': vertex.A
      };
      var result = db._query(query, bindVars).toArray();
      assertEqual(result.length, 1);
      assertEqual(result[0], vertex.C);
    },

    testTraversalLetDocInput: function () {
      var query = `WITH ${vn}
      FOR x IN OUTBOUND @startId @@eCol
      LET next = x
      FOR y IN OUTBOUND next @@eCol
      SORT y._id ASC
      RETURN y._id`;
      var bindVars = {
        '@eCol': en,
        'startId': vertex.A
      };
      var result = db._query(query, bindVars).toArray();
      assertEqual(result.length, 1);
      assertEqual(result[0], vertex.C);
    }

  };
}

function multiEdgeCollectionGraphSuite() {
  /* *********************************************************************
   * Graph under test:
   *
   *         B<----+       <- B & C via edge collection A
   *               |
   *         D<----A----<C
   *               |
   *               +----<E <- D & E via edge colltion B
   *
   ***********************************************************************/
  const gn = 'UnitTestGraph';
  const en2 = 'UnitTestEdgeCollection2';
  var ruleName = 'optimize-traversals';
  var paramEnabled = { optimizer: { rules: ['-all', '+' + ruleName] } };
  var opts = _.clone(paramEnabled);

  return {

    setUpAll: function () {
      opts.allPlans = true;
      opts.verbosePlans = true;
      cleanup();
      try {
        gm._drop(gn);
      } catch (e) {
        // It is expected that this graph does not exist.
      }

      vc = db._create(vn, { numberOfShards: 4 });
      ec = db._createEdgeCollection(en, { numberOfShards: 4 });
      var ec2 = db._createEdgeCollection(en2, { numberOfShards: 4 });

      gm._create(gn, [gm._relation(en, vn, vn), gm._relation(en2, vn, vn)]);

      vertex.A = vc.save({ _key: 'A' })._id;
      vertex.B = vc.save({ _key: 'B' })._id;
      vertex.C = vc.save({ _key: 'C' })._id;
      vertex.D = vc.save({ _key: 'D' })._id;
      vertex.E = vc.save({ _key: 'E' })._id;

      edge.AB = ec.save(vertex.A, vertex.B, {})._id;
      edge.CA = ec.save(vertex.C, vertex.A, {})._id;
      edge.AD = ec2.save(vertex.A, vertex.D, {})._id;
      edge.EA = ec2.save(vertex.E, vertex.A, {})._id;
    },

    tearDownAll: function () {
      gm._drop(gn);
      db._drop(vn);
      db._drop(en);
      db._drop(en2);
      cleanup();
    },

    testTwoVertexCollectionsInOutbound: function () {
      /* this test is intended to trigger the clone functionality. */
      var expectResult = ['B', 'C', 'D', 'E'];
      var query = 'FOR x IN ANY @startId GRAPH @graph SORT x._id RETURN x._key';
      var bindVars = {
        graph: gn,
        startId: vertex.A
      };

      var result = db._query(query, bindVars).toArray();

      assertEqual(result, expectResult, query);
      var plans = AQL_EXPLAIN(query, bindVars, opts).plans;
      plans.forEach(function (plan) {
        var jsonResult = AQL_EXECUTEJSON(plan, { optimizer: { rules: ['-all'] } }).json;
        assertEqual(jsonResult, result, query);
      });
    }

  };
}

function potentialErrorsSuite() {
  var vc, ec;

  return {

    setUpAll: function () {
      cleanup();
      vc = db._create(vn);
      ec = db._createEdgeCollection(en);
      vertex.A = vn + '/unknown';

      vertex.B = vc.save({ _key: 'B' })._id;
      vertex.C = vc.save({ _key: 'C' })._id;
      ec.save(vertex.B, vertex.C, {});
    },

    tearDownAll: cleanup,

    testNonIntegerSteps: function () {
      var query = 'FOR x IN 2.5 OUTBOUND @startId @@eCol RETURN x';
      var bindVars = {
        '@eCol': en,
        'startId': vertex.A
      };
      try {
        db._query(query, bindVars).toArray();
        fail();
      } catch (e) {
        assertEqual(e.errorNum, errors.ERROR_QUERY_PARSE.code);
      }
    },

    testNonNumberSteps: function () {
      var query = 'FOR x IN "invalid" OUTBOUND @startId @@eCol RETURN x';
      var bindVars = {
        '@eCol': en,
        'startId': vertex.A
      };
      try {
        db._query(query, bindVars).toArray();
        fail();
      } catch (e) {
        assertEqual(e.errorNum, errors.ERROR_QUERY_PARSE.code);
      }
    },

    testMultiDirections: function () {
      var query = 'FOR x IN OUTBOUND ANY @startId @@eCol RETURN x';
      var bindVars = {
        '@eCol': en,
        'startId': vertex.A
      };
      try {
        db._query(query, bindVars).toArray();
        fail();
      } catch (e) {
        assertEqual(e.errorNum, errors.ERROR_QUERY_PARSE.code);
      }
    },

    testNoCollections: function () {
      var query = 'FOR x IN OUTBOUND @startId RETURN x';
      var bindVars = {
        'startId': vertex.A
      };
      try {
        db._query(query, bindVars).toArray();
        fail();
      } catch (e) {
        assertEqual(e.errorNum, errors.ERROR_QUERY_PARSE.code);
      }
    },

    testNoStartVertex: function () {
      var query = 'FOR x IN OUTBOUND @@eCol RETURN x';
      var bindVars = {
        '@eCol': en
      };
      try {
        db._query(query, bindVars).toArray();
        fail();
      } catch (e) {
        assertEqual(e.errorNum, errors.ERROR_QUERY_PARSE.code);
      }
    },

    testTooManyOutputParameters: function () {
      var query = 'FOR x, y, z, f IN OUTBOUND @startId @@eCol RETURN x';
      var bindVars = {
        '@eCol': en,
        'startId': vertex.A
      };
      try {
        db._query(query, bindVars).toArray();
        fail();
      } catch (e) {
        assertEqual(e.errorNum, errors.ERROR_QUERY_PARSE.code);
      }
    },

    testTraverseVertexCollection: function () {
      var query = 'FOR x IN OUTBOUND @startId @@eCol, @@vCol RETURN x';
      var bindVars = {
        '@eCol': en,
        '@vCol': vn,
        'startId': vertex.A
      };
      try {
        db._query(query, bindVars).toArray();
        fail(query + ' should not be allowed');
      } catch (e) {
        assertEqual(e.errorNum, errors.ERROR_ARANGO_COLLECTION_TYPE_INVALID.code);
      }
    },

    testStartWithSubquery: function () {
      var query = 'FOR x IN OUTBOUND (FOR y IN @@vCol SORT y._id LIMIT 3 RETURN y) @@eCol SORT x._id RETURN x';
      var bindVars = {
        '@eCol': en,
        '@vCol': vn
      };
      var x = db._query(query, bindVars);
      var result = x.toArray();
      var extra = x.getExtra();
      assertEqual(result, []);
      assertEqual(extra.warnings.length, 1);
    },

    testStepsSubquery: function () {
      var query = `WITH ${vn}
      FOR x IN (FOR y IN 1..1 RETURN y) OUTBOUND @startId @@eCol
      RETURN x`;
      var bindVars = {
        '@eCol': en,
        'startId': vertex.A
      };
      try {
        db._query(query, bindVars).toArray();
        fail();
      } catch (e) {
        assertEqual(e.errorNum, errors.ERROR_QUERY_PARSE.code);
      }
    },

    testCrazyStart1: function () {
      var query = `WITH ${vn}
      FOR x IN OUTBOUND null @@eCol
      RETURN x`;
      var bindVars = {
        '@eCol': en
      };
      try {
        db._query(query, bindVars).toArray();
        fail();
      } catch (e) {
        assertEqual(e.errorNum, errors.ERROR_QUERY_PARSE.code);
      }
    },

    testCrazyStart2: function () {
      var query = `WITH ${vn}
      FOR x IN OUTBOUND 1 @@eCol
      RETURN x`;
      var bindVars = {
        '@eCol': en
      };
      try {
        db._query(query, bindVars).toArray();
        fail();
      } catch (e) {
        assertEqual(e.errorNum, errors.ERROR_QUERY_PARSE.code);
      }
    },

    testCrazyStart3: function () {
      var query = `WITH ${vn}
      FOR x IN OUTBOUND [] @@eCol
      RETURN x`;
      var bindVars = {
        '@eCol': en
      };
      var x = db._query(query, bindVars);
      var result = x.toArray();
      var extra = x.getExtra();
      assertEqual(result, []);
      assertEqual(extra.warnings.length, 1);
    },

    testCrazyStart4: function () {
      var query = `WITH ${vn}
      FOR x IN OUTBOUND "foobar" @@eCol
      RETURN x`;
      var bindVars = {
        '@eCol': en
      };
      var x = db._query(query, bindVars);
      var result = x.toArray();
      var extra = x.getExtra();
      assertEqual(result, []);
      assertEqual(extra.warnings.length, 1);
    },

    testCrazyStart5: function () {
      var query = `WITH ${vn}
      FOR x IN OUTBOUND {foo: "bar"} @@eCol
      RETURN x`;
      var bindVars = {
        '@eCol': en
      };
      var x = db._query(query, bindVars);
      var result = x.toArray();
      var extra = x.getExtra();
      assertEqual(result, []);
      assertEqual(extra.warnings.length, 0);
    },

    testCrazyStart6: function () {
      var query = `WITH ${vn}
      FOR x IN OUTBOUND {_id: @startId} @@eCol
      RETURN x._id`;
      var bindVars = {
        'startId': vertex.B,
        '@eCol': en
      };
      var result = db._query(query, bindVars).toArray();
      assertEqual(result.length, 1);
      assertEqual(result[0], vertex.C);
    },

    testCrazyStart7: function () {
      var query = `FOR x IN OUTBOUND
      (FOR y IN @@vCol FILTER y._id == @startId RETURN y) @@eCol
      RETURN x._id`;
      var bindVars = {
        'startId': vertex.B,
        '@eCol': en,
        '@vCol': vn
      };
      var x = db._query(query, bindVars);
      var result = x.toArray();
      var extra = x.getExtra();
      assertEqual(result, []);
      assertEqual(extra.warnings.length, 1);
      // Fix the query, just use the first value
      query = `WITH ${vn}
      FOR x IN OUTBOUND
      (FOR y IN @@vCol FILTER y._id == @startId RETURN y)[0] @@eCol
      RETURN x._id`;
      result = db._query(query, bindVars).toArray();
      assertEqual(result.length, 1);
      assertEqual(result[0], vertex.C);
    },

    testCrazyStart8: function () {
      var query = `WITH ${vn}
      FOR x IN OUTBOUND
      (FOR y IN @@eCol FILTER y._id == @startId RETURN "peter") @@eCol
      RETURN x._id`;
      var bindVars = {
        'startId': vertex.A,
        '@eCol': en
      };
      var x = db._query(query, bindVars);
      var result = x.toArray();
      var extra = x.getExtra();
      assertEqual(result, []);
      assertEqual(extra.warnings.length, 1);
      // Actually use the string!
      query = `WITH ${vn}
      FOR x IN OUTBOUND
      (FOR y IN @@eCol FILTER y._id == @startId RETURN "peter")[0] @@eCol
      RETURN x._id`;
      result = db._query(query, bindVars).toArray();
      assertEqual(result.length, 0);
    }

  };
}

function complexInternaSuite() {
  var ruleName = 'optimize-traversals';
  var paramEnabled = { optimizer: { rules: ['-all', '+' + ruleName] } };
  var opts = _.clone(paramEnabled);

  return {

    setUp: function () {
      opts.allPlans = true;
      opts.verbosePlans = true;
      cleanup();
      createBaseGraph();
    },

    tearDown: cleanup,

    testUnknownVertexCollection: function () {
      const vn2 = 'UnitTestVertexCollectionOther';
      db._drop(vn2);
      const vc2 = db._create(vn2);
      vc.save({ _key: '1' });
      vc2.save({ _key: '1' });
      ec.save(vn + '/1', vn2 + '/1', {});
      var query = `WITH ${vn2}
      FOR x IN OUTBOUND @startId @@eCol
      RETURN x`;
      var bindVars = {
        '@eCol': en,
        'startId': vn + '/1'
      };
      // NOTE: vn2 is not explicitly named in AQL
      var result = db._query(query, bindVars).toArray();
      assertEqual(result.length, 1);
      assertEqual(result[0]._id, vn2 + '/1');
      db._drop(vn2);
    },

    testStepsFromLet: function () {
      var query = `WITH ${vn}
      LET s = 1
      FOR x IN s OUTBOUND @startId @@eCol
      RETURN x`;
      var bindVars = {
        '@eCol': en,
        'startId': vertex.A
      };

      var result = db._query(query, bindVars).toArray();
      assertEqual(result.length, 1);
      assertEqual(result[0]._id, vertex.B);
    },

    testMultipleBlocksResult: function () {
      var query = `WITH ${vn}
      FOR x IN OUTBOUND @startId @@eCol
      SORT x._key RETURN x`;
      var amount = 10000;
      var startId = vn + '/test';
      var bindVars = {
        '@eCol': en,
        'startId': startId
      };
      vc.save({ _key: startId.split('/')[1] });

      // Insert amount many edges and vertices into the collections.
      for (var i = 0; i < amount; ++i) {
        var tmp = vc.save({ _key: '' + i })._id;
        ec.save(startId, tmp, {});
      }

      // Check that we can get all of them out again.
      var result = db._query(query, bindVars).toArray();
      // Internally: The Query selects elements in chunks, check that nothing is lost.
      assertEqual(result.length, amount);
      var plans = AQL_EXPLAIN(query, bindVars, opts).plans;
      plans.forEach(function (plan) {
        var jsonResult = AQL_EXECUTEJSON(plan, { optimizer: { rules: ['-all'] } }).json;
        assertEqual(jsonResult, result, query);
      });
    },

    testSkipSome: function () {
      var query = `WITH ${vn}
      FOR x, e, p IN 1..2 OUTBOUND @startId @@eCol
      LIMIT 4, 100
      RETURN p.vertices[1]._key`;
      var startId = vn + '/test';
      var bindVars = {
        '@eCol': en,
        'startId': startId
      };
      vc.save({ _key: startId.split('/')[1] });

      // Insert amount many edges and vertices into the collections.
      for (var i = 0; i < 3; ++i) {
        var tmp = vc.save({ _key: '' + i })._id;
        ec.save(startId, tmp, {});
        for (var k = 0; k < 3; ++k) {
          var tmp2 = vc.save({ _key: '' + i + '_' + k })._id;
          ec.save(tmp, tmp2, {});
        }
      }

      // Check that we can get all of them out again.
      var result = db._query(query, bindVars).toArray();
      // Internally: The Query selects elements in chunks, check that nothing is lost.
      assertEqual(result.length, 8);

      // Each of the 3 parts of this graph contains of 4 nodes, one connected to the start.
      // And 3 connected to the first one. As we do a depth first traversal we expect to skip
      // exactly one sub-tree. Therefor we expect exactly two sub-trees to be traversed.
      var seen = {};
      for (var r of result) {
        if (!seen.hasOwnProperty(r)) {
          seen[r] = true;
        }
      }
      assertEqual(Object.keys(seen).length, 2);
      var plans = AQL_EXPLAIN(query, bindVars, opts).plans;
      plans.forEach(function (plan) {
        var jsonResult = AQL_EXECUTEJSON(plan, { optimizer: { rules: ['-all'] } }).json;
        assertEqual(jsonResult, result, query);
      });
    },

    testManyResults: function () {
      var query = `WITH ${vn}
      FOR x IN OUTBOUND @startId @@eCol
      RETURN x._key`;
      var startId = vn + '/many';
      var bindVars = {
        '@eCol': en,
        'startId': startId
      };
      vc.save({ _key: startId.split('/')[1] });
      var amount = 10000;
      for (var i = 0; i < amount; ++i) {
        var _id = vc.save({});
        ec.save(startId, _id, {});
      }
      var result = db._query(query, bindVars);
      var found = 0;
      // Count has to be correct
      assertEqual(result.count(), amount);
      while (result.hasNext()) {
        result.next();
        ++found;
      }
      // All elements must be enumerated
      assertEqual(found, amount);
    },

    testTailRecursion: function () {
      // This test is to make sure their is no
      // inifinite callstack in getSome() API
      let query = `
      WITH ${vn}
      FOR id IN 0..100000
      FOR v IN OUTBOUND CONCAT("${vn}/foobar", id) ${en}
      RETURN v
      `;

      let res = db._query(query);
      assertEqual(res.count(), 0);
      // With inifinit callstack in getSome this
      // test will segfault
    },

    testEdgeOptimizeAboveMinDepth: function () {
      // The query should return depth 1
      // Because edges[1] == null => null != edge.BC => ok
      // And not depth 2/3 because edges[1]._id == edge.BC => not okay
      let query = `
      WITH ${vn}
      FOR v, e, p IN 1..3 OUTBOUND "${vn}/A" ${en}
      FILTER p.edges[1]._id != "${edge.BC}"
      RETURN v._id`;

      let res = db._query(query);
      assertEqual(res.count(), 1);
      assertEqual(res.toArray(), [vertex.B]);
    },

    testVertexOptimizeAboveMinDepth: function () {
      // The query should return depth 1
      // Because vertices[2] == null => null != vertex.C => ok
      // And not depth 2/3 because vertices[3]._id == vertex.C => not okay
      let query = `
      WITH ${vn}
      FOR v, e, p IN 1..3 OUTBOUND "${vn}/A" ${en}
      FILTER p.vertices[2]._id != "${vertex.C}"
      RETURN v._id`;

      let res = db._query(query);
      assertEqual(res.count(), 1);
      assertEqual(res.toArray(), [vertex.B]);
    },

    testPathOptimizeAboveMinDepth: function () {
      // The query should return depth 1
      // Because vertices[2] == null => null != vertex.C => ok
      // And not depth 2/3 because vertices[3]._id == vertex.C => not okay
      let query = `
      WITH ${vn}
      FOR v, e, p IN 1..3 OUTBOUND "${vn}/A" ${en}
      FILTER p.edges[1]._id != "${edge.BC}"
      FILTER p.vertices[2]._id != "${vertex.C}"
      RETURN v._id`;

      let res = db._query(query);
      assertEqual(res.count(), 1);
      assertEqual(res.toArray(), [vertex.B]);
    },

    testLargeMaxDepth: function () {
      let query = `
      WITH ${vn}
      FOR v, e, p IN 1..4294967295 OUTBOUND "${vn}/A" ${en}
      FILTER p.edges[1]._id != "${edge.BC}"
      FILTER p.vertices[2]._id != "${vertex.C}"
      RETURN v._id`;

      let res = db._query(query);
      assertEqual(res.count(), 1);
      assertEqual(res.toArray(), [vertex.B]);
    },

    testInt64MaxMaxDepth: function () {
      let query = `
      WITH ${vn}
      FOR v, e, p IN 1..9223372036854775807 OUTBOUND "${vn}/A" ${en}
      FILTER p.edges[1]._id != "${edge.BC}"
      FILTER p.vertices[2]._id != "${vertex.C}"
      RETURN v._id`;

      let res = db._query(query);
      assertEqual(res.count(), 1);
      assertEqual(res.toArray(), [vertex.B]);
    },


    testEvenLargerMaxDepth: function () {
      let query = `
      WITH ${vn}
      FOR v, e, p IN 1..18446744073709551615 OUTBOUND "${vn}/A" ${en}
      FILTER p.edges[1]._id != "${edge.BC}"
      FILTER p.vertices[2]._id != "${vertex.C}"
      RETURN v._id`;

      try {
        db._query(query);
        fail();
      } catch (e) {
        assertEqual(e.errorNum, errors.ERROR_QUERY_PARSE.code);
      }
    },

    testNegativeMinDepth: function () {
      let query = `
      WITH ${vn}
      FOR v, e, p IN -1..3 OUTBOUND "${vn}/A" ${en}
      FILTER p.edges[1]._id != "${edge.BC}"
      FILTER p.vertices[2]._id != "${vertex.C}"
      RETURN v._id`;
      try {
        db._query(query);
        fail();
      } catch (e) {
        assertEqual(e.errorNum, errors.ERROR_QUERY_PARSE.code);
      }
    },

    testNegativeMaxDepth: function () {
      let query = `
      WITH ${vn}
      FOR v, e, p IN 1..-3 OUTBOUND "${vn}/A" ${en}
      FILTER p.edges[1]._id != "${edge.BC}"
      FILTER p.vertices[2]._id != "${vertex.C}"
      RETURN v._id`;

      try {
        db._query(query);
        fail();
      } catch (e) {
        assertEqual(e.errorNum, errors.ERROR_QUERY_PARSE.code);
      }
    },

  };
}

function optimizeInSuite() {
  var ruleName = 'optimize-traversals';
  var startId = vn + '/optIn';

  return {

    setUpAll: function () {
      cleanup();
      vc = db._create(vn, { numberOfShards: 4 });
      ec = db._createEdgeCollection(en, { numberOfShards: 4 });
      vc.save({ _key: startId.split('/')[1] });

      for (var i = 0; i < 100; ++i) {
        var tmp = vc.save({ _key: 'tmp' + i, value: i });
        ec.save(startId, tmp._id, { _key: 'tmp' + i, value: i });
        for (var j = 0; j < 100; ++j) {
          var innerTmp = vc.save({ _key: 'innertmp' + i + '_' + j });
          ec.save(tmp._id, innerTmp._id, {});
        }
      }
    },

    tearDownAll: cleanup,

    testSingleOptimize: function () {
      internal.waitForEstimatorSync(); // make sure estimates are consistent
      var vertexQuery = `WITH ${vn}
      FOR v, e, p IN 2 OUTBOUND @startId @@eCol
      FILTER p.vertices[1]._key IN @keys
      RETURN v._key`;
      var edgeQuery = `WITH ${vn}
      FOR v, e, p IN 2 OUTBOUND @startId @@eCol
      FILTER p.edges[0]._key IN @keys
      RETURN v._key`;
      var bindVars = {
        '@eCol': en,
        'startId': startId,
        'keys': ['tmp0', 'tmp1', 'tmp2', 'tmp3', 'tmp4', 'tmp5', 'tmp6', 'tmp7', 'tmp8', 'tmp9']
      };

      var result = db._query(vertexQuery, bindVars);
      var extra = result.getExtra();

      // We have only 10 valid elements in the array.
      assertEqual(extra.stats.filtered, 90);
      assertEqual(result.count(), 1000);

      result = db._query(edgeQuery, bindVars);
      extra = result.getExtra();
      if (isCluster) {
        // The cluster uses a different index no filtering on _key
        // this unfortunately depends on the storage engine used
        assertTrue(extra.stats.filtered === 90 || extra.stats.filtered === 0);
      } else {
        // We have only 10 valid elements in the array.
        assertEqual(extra.stats.filtered, 0);
      }
      assertEqual(result.count(), 1000);

      // if the rule is disabled we expect to do way more filtering
      var noOpt = { optimizer: { rules: ['-all'] } };
      result = db._query(vertexQuery, bindVars, {}, noOpt);

      extra = result.getExtra();
      // For each vertex not in the list we filter once for every connected edge
      assertEqual(extra.stats.filtered, 90 * 100);
      assertEqual(result.count(), 1000);

      result = db._query(edgeQuery, bindVars, {}, noOpt);
      extra = result.getExtra();
      // For each vertex not in the list we filter once for every connected edge
      assertEqual(extra.stats.filtered, 90 * 100);
      assertEqual(result.count(), 1000);
    },

    testCombinedAndOptimize: function () {
      internal.waitForEstimatorSync(); // make sure estimates are consistent
      var vertexQuery = `WITH ${vn}
      FOR v, e, p IN 2 OUTBOUND @startId @@eCol
      FILTER p.vertices[1]._key IN @keys
      AND p.vertices[1].value IN @values
      RETURN v._key`;
      var edgeQuery = `WITH ${vn}
      FOR v, e, p IN 2 OUTBOUND @startId @@eCol
      FILTER p.edges[0]._key IN @keys
      AND p.edges[0].value IN @values
      RETURN v._key`;
      var mixedQuery1 = `WITH ${vn}
      FOR v, e, p IN 2 OUTBOUND @startId @@eCol
      FILTER p.edges[0]._key IN @keys
      AND p.vertices[1].value IN @values
      RETURN v._key`;
      var mixedQuery2 = `WITH ${vn}
      FOR v, e, p IN 2 OUTBOUND @startId @@eCol
      FILTER p.vertices[1]._key IN @keys
      AND p.edges[0].value IN @values
      RETURN v._key`;
      var bindVars = {
        '@eCol': en,
        'startId': startId,
        'keys': ['tmp0', 'tmp1', 'tmp2', 'tmp3', 'tmp4', 'tmp5', 'tmp6', 'tmp7', 'tmp8', 'tmp9'],
        'values': [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
      };

      var result = db._query(vertexQuery, bindVars);
      var extra = result.getExtra();

      // We have only 10 valid elements in the array.
      assertEqual(extra.stats.filtered, 90);
      assertEqual(result.count(), 1000);

      result = db._query(edgeQuery, bindVars);
      extra = result.getExtra();

      if (isCluster) {
        // The cluster uses a different index no filtering on _key
        // this unfortunately depends on the storage engine used
        assertTrue(extra.stats.filtered === 90 || extra.stats.filtered === 0);
      } else {
        // We have only 10 valid elements in the array.
        assertEqual(extra.stats.filtered, 0);
      }
      assertEqual(result.count(), 1000);

      result = db._query(mixedQuery1, bindVars);
      extra = result.getExtra();

      if (isCluster) {
        // The cluster uses a different index no filtering on _key
        // this unfortunately depends on the storage engine used
        assertTrue(extra.stats.filtered === 90 || extra.stats.filtered === 0);
      } else {
        // We have only 10 valid elements in the array.
        assertEqual(extra.stats.filtered, 0);
      }
      assertEqual(result.count(), 1000);

      result = db._query(mixedQuery2, bindVars);
      extra = result.getExtra();
      // We have only 10 valid elements in the array.
      assertEqual(extra.stats.filtered, 90);
      assertEqual(result.count(), 1000);

      // if the rule is disabled we expect to do way more filtering
      var noOpt = { optimizer: { rules: ['-all'] } };
      result = db._query(vertexQuery, bindVars, {}, noOpt);
      extra = result.getExtra();
      // For each vertex not in the list we filter once for every connected edge
      assertEqual(extra.stats.filtered, 90 * 100);
      assertEqual(result.count(), 1000);

      result = db._query(edgeQuery, bindVars, {}, noOpt);
      extra = result.getExtra();
      // For each vertex not in the list we filter once for every connected edge
      assertEqual(extra.stats.filtered, 90 * 100);
      assertEqual(result.count(), 1000);

      result = db._query(mixedQuery1, bindVars, {}, noOpt);
      extra = result.getExtra();
      // For each vertex not in the list we filter once for every connected edge
      assertEqual(extra.stats.filtered, 90 * 100);
      assertEqual(result.count(), 1000);

      result = db._query(mixedQuery2, bindVars, {}, noOpt);
      extra = result.getExtra();
      // For each vertex not in the list we filter once for every connected edge
      assertEqual(extra.stats.filtered, 90 * 100);
      assertEqual(result.count(), 1000);
    },

    testCombinedNoOptimize: function () {
      var vertexQuery = `WITH ${vn}
      FOR v, e, p IN 2 OUTBOUND @startId @@eCol
      FILTER @obj IN p.vertices
      RETURN [v, e, p]`;
      var edgeQuery = `WITH ${vn}
      FOR v, e, p IN 2 OUTBOUND @startId @@eCol
      FILTER @obj IN p.edges
      RETURN [v, e, p]`;
      var bindVars = {
        '@eCol': en,
        'startId': startId,
        'obj': { '_key': 'tmp0', 'value': 0 }
      };

      var noOpt = { optimizer: { rules: ['-all'] } };
      var opt = { optimizer: { rules: ['-all', '+' + ruleName] } };

      var optPlans = AQL_EXPLAIN(vertexQuery, bindVars, opt).plan;
      var noOptPlans = AQL_EXPLAIN(vertexQuery, bindVars, noOpt).plan;
      assertEqual(optPlans.rules, []);
      // This query cannot be optimized by traversal rule
      assertEqual(roundCost(optPlans), roundCost(noOptPlans));

      optPlans = AQL_EXPLAIN(edgeQuery, bindVars, opt).plan;
      noOptPlans = AQL_EXPLAIN(edgeQuery, bindVars, noOpt).plan;
      assertEqual(optPlans.rules, []);
      // This query cannot be optimized by traversal rule
      assertEqual(roundCost(optPlans), roundCost(noOptPlans));
    }
  };
}

function complexFilteringSuite() {
  /* *********************************************************************
   * Graph under test:
   *
   * C <- B <- A -> D -> E
   * F <--|         |--> G
   *
   *
   * Tri1 --> Tri2
   *  ^        |
   *  |--Tri3<-|
   *
   *
   ***********************************************************************/
  return {
    setUpAll: function () {
      cleanup();
      var vc = db._create(vn, { numberOfShards: 4 });
      var ec = db._createEdgeCollection(en, { numberOfShards: 4 });
      vertex.A = vc.save({ _key: 'A', left: false, right: false })._id;
      vertex.B = vc.save({ _key: 'B', left: true, right: false, value: 25 })._id;
      vertex.C = vc.save({ _key: 'C', left: true, right: false })._id;
      vertex.D = vc.save({ _key: 'D', left: false, right: true, value: 75 })._id;
      vertex.E = vc.save({ _key: 'E', left: false, right: true })._id;
      vertex.F = vc.save({ _key: 'F', left: true, right: false })._id;
      vertex.G = vc.save({ _key: 'G', left: false, right: true })._id;

      edge.AB = ec.save(vertex.A, vertex.B, { left: true, right: false })._id;
      edge.BC = ec.save(vertex.B, vertex.C, { left: true, right: false })._id;
      edge.AD = ec.save(vertex.A, vertex.D, { left: false, right: true })._id;
      edge.DE = ec.save(vertex.D, vertex.E, { left: false, right: true })._id;
      edge.BF = ec.save(vertex.B, vertex.F, { left: true, right: false })._id;
      edge.DG = ec.save(vertex.D, vertex.G, { left: false, right: true })._id;

      vertex.Tri1 = vc.save({ _key: 'Tri1', isLoop: true })._id;
      vertex.Tri2 = vc.save({ _key: 'Tri2', isLoop: true })._id;
      vertex.Tri3 = vc.save({ _key: 'Tri3', isLoop: true })._id;

      edge.Tri12 = ec.save(vertex.Tri1, vertex.Tri2, { isLoop: true })._id;
      edge.Tri23 = ec.save(vertex.Tri2, vertex.Tri3, { isLoop: true })._id;
      edge.Tri31 = ec.save(vertex.Tri3, vertex.Tri1, { isLoop: true, lateLoop: true })._id;
    },

    tearDownAll: cleanup,

    testPruneWithSubquery: function () {
      let query = `FOR v,e,p IN 1..100 OUTBOUND @start @ecol PRUNE 2 <= LENGTH(FOR w IN p.vertices FILTER w._id == v._id RETURN 1) RETURN p`;
      try {
        let bindVars = {
          '@eCol': en,
          'start': vertex.Tri1
        };
        db._query(query, bindVars);
        fail();
      } catch (err) {
        assertEqual(err.errorNum, errors.ERROR_QUERY_PARSE.code);
      }
    },

    testVertexEarlyPruneHighDepth: function () {
      var query = `WITH ${vn}
      FOR v, e, p IN 100 OUTBOUND @start @@eCol
      FILTER p.vertices[1]._key == "wrong"
      RETURN v`;
      var bindVars = {
        '@eCol': en,
        'start': vertex.Tri1
      };
      var cursor = db._query(query, bindVars);
      assertEqual(cursor.count(), 0);
      var stats = cursor.getExtra().stats;
      assertEqual(stats.scannedFull, 0);
      // 1 Primary (Tri1)
      // 1 Edge (Tri1->Tri2)
      // 1 Primary (Tri2)

      if (mmfilesEngine) {
        assertEqual(stats.scannedIndex, 2);
      } else {
        assertEqual(stats.scannedIndex, 1);
      }

      assertEqual(stats.filtered, 1);
    },

    testStartVertexEarlyPruneHighDepth: function () {
      var query = `WITH ${vn}
      FOR v, e, p IN 100 OUTBOUND @start @@eCol
      FILTER p.vertices[0]._key == "wrong"
      RETURN v`;
      var bindVars = {
        '@eCol': en,
        'start': vertex.Tri1
      };
      var cursor = db._query(query, bindVars);
      assertEqual(cursor.count(), 0);
      var stats = cursor.getExtra().stats;
      assertEqual(stats.scannedFull, 0);
      // 1 Primary (Tri1)
      assertEqual(stats.scannedIndex, 1);
      assertEqual(stats.filtered, 1);
    },

    testEdgesEarlyPruneHighDepth: function () {
      var query = `WITH ${vn}
      FOR v, e, p IN 100 OUTBOUND @start @@eCol
      FILTER p.edges[0]._key == "wrong"
      RETURN v`;
      var bindVars = {
        '@eCol': en,
        'start': vertex.Tri1
      };
      var cursor = db._query(query, bindVars);
      assertEqual(cursor.count(), 0);
      var stats = cursor.getExtra().stats;
      assertEqual(stats.scannedFull, 0);
      // The lookup will be using the primary Index.
      // It will find 0 elements.
      if (mmfilesEngine) {
        assertEqual(stats.scannedIndex, 1);
        assertEqual(stats.filtered, 1);
      } else {
        assertEqual(stats.scannedIndex, 0);
        assertEqual(stats.filtered, 0);
      }
    },

    testVertexLevel0: function () {
      var query = `WITH ${vn}
      FOR v, e, p IN 1..2 OUTBOUND @start @@ecol
      FILTER p.vertices[0].left == true
      SORT v._key
      RETURN v._key`;
      var bindVars = {
        '@ecol': en,
        start: vertex.A
      };
      var cursor = db._query(query, bindVars);
      assertEqual(cursor.count(), 0);
      var stats = cursor.getExtra().stats;
      assertEqual(stats.scannedFull, 0);
      // 1 Primary (A)
      // 0 Edge
      assertEqual(stats.scannedIndex, 1);
      // 1 Filter (A)
      assertEqual(stats.filtered, 1);
    },

    testVertexLevel1: function () {
      var query = `WITH ${vn}
      FOR v, e, p IN 1..2 OUTBOUND @start @@ecol
      FILTER p.vertices[1].left == true
      SORT v._key
      RETURN v._key`;
      var bindVars = {
        '@ecol': en,
        start: vertex.A
      };
      var cursor = db._query(query, bindVars);
      assertEqual(cursor.count(), 3);
      assertEqual(cursor.toArray(), ['B', 'C', 'F']);
      var stats = cursor.getExtra().stats;
      assertEqual(stats.scannedFull, 0);
      if (isCluster) {
        // 1 Primary lookup A
        // 2 Edge Lookups (A)
        // 2 Primary lookup B,D
        // 2 Edge Lookups (2 B) (0 D)
        // 2 Primary Lookups (C, F)
        if (mmfilesEngine) {
          assertTrue(stats.scannedIndex <= 9);
        } else {
          assertTrue(stats.scannedIndex <= 5);
        }
      } else {
        // 2 Edge Lookups (A)
        // 2 Primary (B, D) for Filtering
        // 2 Edge Lookups (B)
        // All edges are cached
        // 1 Primary Lookups A -> B (B cached)
        // 1 Primary Lookups A -> B -> C (A, B cached)
        // 1 Primary Lookups A -> B -> F (A, B cached)
        // With traverser-read-cache
        // assertEqual(stats.scannedIndex, 9);

        // Without traverser-read-cache
        assertTrue(stats.scannedIndex <= 17);
        /*
          if(mmfilesEngine){
          assertEqual(stats.scannedIndex, 17);
          } else {
          assertEqual(stats.scannedIndex, 13);
          }
        */
      }
      // 1 Filter On D
      assertEqual(stats.filtered, 1);
    },

    testVertexLevel2: function () {
      var query = `WITH ${vn}
      FOR v, e, p IN 1..2 OUTBOUND @start @@ecol
      FILTER p.vertices[2].left == true
      SORT v._key
      RETURN v._key`;
      var bindVars = {
        '@ecol': en,
        start: vertex.A
      };
      var cursor = db._query(query, bindVars);
      // We expect to find C, F
      // B and D will be post filtered
      assertEqual(cursor.count(), 2);
      assertEqual(cursor.toArray(), ['C', 'F']);
      var stats = cursor.getExtra().stats;
      assertEqual(stats.scannedFull, 0);
      if (isCluster) {
        // 1 Primary lookup A
        // 2 Primary lookup B,D
        // 4 Primary Lookups (C, F, E, G)
        if (mmfilesEngine) {
          assertTrue(stats.scannedIndex <= 13);
        } else {
          assertTrue(stats.scannedIndex <= 7);
        }
      } else {
        // 2 Edge Lookups (A)
        // 4 Edge Lookups (2 B) (2 D)
        // 4 Primary Lookups for Eval (C, E, G, F)
        // 2 Primary Lookups A -> B (A, B)
        // 1 Primary Lookups A -> D (D)
        // 0 Primary Lookups A -> B -> C
        // 0 Primary Lookups A -> B -> F
        // Without traverser-read-cache
        // assertEqual(stats.scannedIndex, 13);

        // With traverser-read-cache
        assertTrue(stats.scannedIndex <= 24);
        /*
          if(mmfilesEngine){
          assertEqual(stats.scannedIndex, 24);
          } else {
          assertEqual(stats.scannedIndex, 18);
          }
        */
      }
      // 2 Filter (B, C) too short
      // 2 Filter (E, G)
      assertTrue(stats.filtered <= 4);
    },

    testVertexLevelsCombined: function () {
      var query = `WITH ${vn}
      FOR v, e, p IN 1..2 OUTBOUND @start @@ecol
      FILTER p.vertices[1].right == true
      FILTER p.vertices[2].left == true
      SORT v._key
      RETURN v._key`;
      var bindVars = {
        '@ecol': en,
        start: vertex.A
      };
      var cursor = db._query(query, bindVars);
      // Everything should be filtered, no results
      assertEqual(cursor.count(), 0);
      var stats = cursor.getExtra().stats;
      assertEqual(stats.scannedFull, 0);
      if (isCluster) {
        // 2 Edge Lookups (A)
        // 2 Primary lookup B,D
        // 2 Edge Lookups (0 B) (2 D)
        // 2 Primary Lookups (E, G)
        if (mmfilesEngine) {
          assertTrue(stats.scannedIndex <= 9);
        } else {
          assertTrue(stats.scannedIndex <= 5);
        }
      } else {
        // 2 Edge Lookups (A)
        // 2 Primary Lookups for Eval (B, D)
        // 2 Edge Lookups (0 B) (2 D)
        // 2 Primary Lookups for Eval (E, G)
        // 1 Primary Lookups A -> D
        // With traverser-read-cache
        // assertEqual(stats.scannedIndex, 9);

        // Without traverser-read-cache
        assertTrue(stats.scannedIndex <= 11);
        /*
          if(mmfilesEngine){
          assertEqual(stats.scannedIndex, 11);
          } else {
          assertEqual(stats.scannedIndex, 7);
          }
        */
      }
      // 2 Filter (B, D) too short
      // 2 Filter (E, G)
      assertTrue(stats.filtered <= 4);
    },

    testEdgeLevel0: function () {
      var query = `WITH ${vn}
      FOR v, e, p IN 1..2 OUTBOUND @start @@ecol
      FILTER p.edges[0].left == true
      SORT v._key
      RETURN v._key`;
      var bindVars = {
        '@ecol': en,
        start: vertex.A
      };
      var cursor = db._query(query, bindVars);
      assertEqual(cursor.count(), 3);
      assertEqual(cursor.toArray(), ['B', 'C', 'F']);
      var stats = cursor.getExtra().stats;
      assertEqual(stats.scannedFull, 0);
      if (isCluster) {
        // 2 Edge
        // 1 Primary (B)
        // 2 Edge
        // 2 Primary (C,F)
        if (mmfilesEngine) {
          assertTrue(stats.scannedIndex <= 8);
        } else {
          assertTrue(stats.scannedIndex <= 4);
        }
      } else {
        // 2 Edge Lookups (A)
        // 2 Edge Lookups (B)
        // 2 Primary Lookups A -> B
        // 1 Primary Lookups A -> B -> C
        // 1 Primary Lookups A -> B -> F
        // With traverser-read-cache
        // assertEqual(stats.scannedIndex, 8);

        // Without traverser-read-cache
        assertTrue(stats.scannedIndex <= 15);
        /*
          if (mmfilesEngine){
          assertEqual(stats.scannedIndex, 15);
          } else {
          assertEqual(stats.scannedIndex, 11);
          }
        */
      }
      // 1 Filter (A->D)
      assertEqual(stats.filtered, 1);
    },

    testEdgeLevel1: function () {
      var query = `WITH ${vn}
      FOR v, e, p IN 1..2 OUTBOUND @start @@ecol
      FILTER p.edges[1].left == true
      SORT v._key
      RETURN v._key`;
      var bindVars = {
        '@ecol': en,
        start: vertex.A
      };
      var cursor = db._query(query, bindVars);
      assertEqual(cursor.count(), 2);
      assertEqual(cursor.toArray(), ['C', 'F']);
      var stats = cursor.getExtra().stats;
      assertEqual(stats.scannedFull, 0);
      if (isCluster) {
        // 2 Edge Lookups (A)
        // 4 Edge Lookups (2 B) (2 D)
        // 2 Primary Lookups (C, F)
        // It may be that B or D are fetched accidentially
        // they may be inserted in the vertexToFetch list, which
        // lazy loads all vertices in it.
        if (stats.scannedIndex !== 8) {
          if (mmfilesEngine) {
            assertTrue(stats.scannedIndex <= 11);
          } else {
            assertTrue(stats.scannedIndex <= 5);
          }
        }
      } else {
        // 2 Edge Lookups (A)
        // 4 Edge Lookups (2 B) (2 D)
        // 2 Primary Lookups A -> B
        // 1 Primary Lookups A -> D
        // 1 Primary Lookups A -> B -> C
        // 1 Primary Lookups A -> B -> F
        // With traverser-read-cache
        // assertEqual(stats.scannedIndex, 11);

        // Without traverser-read-cache
        assertTrue(stats.scannedIndex <= 20);
        /*
          if(mmfilesEngine){
          assertEqual(stats.scannedIndex, 20);
          } else {
          assertEqual(stats.scannedIndex, 14);
          }
        */
      }
      // 2 Filter On (B, D) too short
      // 2 Filter On (D->E, D->G)
      assertTrue(stats.filtered <= 4);
    },

    testVertexLevel1Less: function () {
      var filters = [
        'FILTER p.vertices[1].value <= 50',
        'FILTER p.vertices[1].value <= 25',
        'FILTER 25 >= p.vertices[1].value',
        'FILTER 50 >= p.vertices[1].value',
        'FILTER p.vertices[1].value < 50',
        'FILTER p.vertices[1].value < 75',
        'FILTER 75 > p.vertices[1].value',
        'FILTER 50 > p.vertices[1].value'
      ];
      for (var f of filters) {
        var query = `WITH ${vn}
        FOR v, e, p IN 1..2 OUTBOUND @start @@ecol
        ${f}
        SORT v._key
        RETURN v._key`;
        var bindVars = {
          '@ecol': en,
          start: vertex.A
        };
        var cursor = db._query(query, bindVars);
        assertEqual(cursor.count(), 3, query);
        assertEqual(cursor.toArray(), ['B', 'C', 'F']);
        var stats = cursor.getExtra().stats;
        assertEqual(stats.scannedFull, 0);
        if (isCluster) {
          // 1 Primary lookup A
          // 2 Edge Lookups (A)
          // 2 Primary lookup B,D
          // 2 Edge Lookups (2 B) (0 D)
          // 2 Primary Lookups (C, F)
          if (mmfilesEngine) {
            assertTrue(stats.scannedIndex <= 9);
          } else {
            // FIXME this used to be 5 ??
            assertTrue(stats.scannedIndex <= 5, stats.scannedIndex);
            // assertEqual(stats.scannedIndex <= 5);
          }
        } else {
          // Cluster uses a lookup cache.
          // Pointless in single-server mode
          // Makes Primary Lookups for data

          // 2 Edge Lookups (A)
          // 2 Primary (B, D) for Filtering
          // 2 Edge Lookups (B)
          // 1 Primary Lookups A -> B
          // 1 Primary Lookups A -> B -> C
          // 1 Primary Lookups A -> B -> F
          // With traverser-read-cache
          // assertEqual(stats.scannedIndex, 9);

          // Without traverser-read-cache
          assertTrue(stats.scannedIndex <= 17);
          /*
            if(mmfilesEngine){
            assertEqual(stats.scannedIndex, 17);
            } else {
            assertEqual(stats.scannedIndex, 13);
            }
          */
        }
        // 1 Filter On D
        assertEqual(stats.filtered, 1);
      }
    },

    testVertexLevel1Greater: function () {
      var filters = [
        'FILTER p.vertices[1].value > 50',
        'FILTER p.vertices[1].value > 25',
        'FILTER 25 < p.vertices[1].value',
        'FILTER 50 < p.vertices[1].value',
        'FILTER p.vertices[1].value > 50',
        'FILTER p.vertices[1].value >= 75',
        'FILTER 75 <= p.vertices[1].value',
        'FILTER 50 < p.vertices[1].value'
      ];
      for (var f of filters) {
        var query = `WITH ${vn}
        FOR v, e, p IN 1..2 OUTBOUND @start @@ecol
        ${f}
        SORT v._key
        RETURN v._key`;
        var bindVars = {
          '@ecol': en,
          start: vertex.A
        };
        var cursor = db._query(query, bindVars);
        assertEqual(cursor.count(), 3, query);
        assertEqual(cursor.toArray(), ['D', 'E', 'G']);
        var stats = cursor.getExtra().stats;
        assertEqual(stats.scannedFull, 0);
        if (isCluster) {
          // 1 Primary lookup A
          // 2 Edge Lookups (A)
          // 2 Primary lookup B,D
          // 2 Edge Lookups (2 B) (0 D)
          // 2 Primary Lookups (C, F)
          if (mmfilesEngine) {
            assertTrue(stats.scannedIndex <= 9);
          } else {
            assertTrue(stats.scannedIndex <= 5);
          }
        } else {
          // Cluster uses a lookup cache.
          // Pointless in single-server mode
          // Makes Primary Lookups for data

          // 2 Edge Lookups (A)
          // 2 Primary (B, D) for Filtering
          // 2 Edge Lookups (B)
          // 1 Primary Lookups A -> B
          // 1 Primary Lookups A -> B -> C
          // 1 Primary Lookups A -> B -> F
          // With traverser-read-cache
          // assertEqual(stats.scannedIndex, 9);

          // Without traverser-read-cache
          assertTrue(stats.scannedIndex <= 17);
          /*
            if(mmfilesEngine){
            assertEqual(stats.scannedIndex, 17);
            } else {
            assertEqual(stats.scannedIndex, 13);
            }
          */
        }
        // 1 Filter On D
        assertEqual(stats.filtered, 1);
      }
    },

    testModify: function () {
      var query = `WITH ${vn}
      FOR v, e, p IN 1..2 OUTBOUND @start @@ecol
      UPDATE v WITH {updated: true} IN @@vcol
      FILTER p.vertices[1].left == true
      SORT v._key
      RETURN v._key`;
      var bindVars = {
        '@ecol': en,
        '@vcol': vn,
        start: vertex.A
      };
      var cursor = db._query(query, bindVars);
      assertEqual(cursor.count(), 3);
      assertEqual(cursor.toArray(), ['B', 'C', 'F']);
      var stats = cursor.getExtra().stats;
      assertEqual(stats.writesExecuted, 6);
      assertEqual(stats.scannedFull, 0);
      if (isCluster) {
        // 1 Primary lookup A
        // 2 Edge Lookups (A)
        // 2 Primary lookup B,D
        // 2 Edge Lookups (2 B) (0 D)
        // 2 Primary Lookups (C, F)
        if (mmfilesEngine) {
          assertTrue(stats.scannedIndex <= 13);
        } else {
          assertTrue(stats.scannedIndex <= 7);
        }
      } else {
        // 2 Edge Lookups (A)
        // 2 Primary (B, D) for Filtering
        // 2 Edge Lookups (B)
        // All edges are cached
        // 1 Primary Lookups A -> B (B cached)
        // 1 Primary Lookups A -> B -> C (A, B cached)
        // 1 Primary Lookups A -> B -> F (A, B cached)
        // With traverser-read-cache
        // assertEqual(stats.scannedIndex, 9);

        // Without traverser-read-cache
        assertTrue(stats.scannedIndex <= 28);
        /*
          if(mmfilesEngine){
          assertEqual(stats.scannedIndex, 17);
          } else {
          assertEqual(stats.scannedIndex, 13);
          }
        */
      }
      // 1 Filter On D
      assertEqual(stats.filtered, 3);
    },

  };
}

function brokenGraphSuite() {
  var paramDisabled = { optimizer: { rules: ['-all'] } };

  return {

    setUpAll: function () {
      cleanup();
      vc = db._create(vn, { numberOfShards: 4 });
      ec = db._createEdgeCollection(en, { numberOfShards: 4 });

      vertex.A = vc.save({ _key: 'A' })._id;
      vertex.B = vc.save({ _key: 'B' })._id;

      ec.save(vertex.A, vn + '/missing', {});
      ec.save(vn + '/missing', vertex.B, {});
    },

    tearDownAll: cleanup,

    testRequestMissingVertex: function () {
      var query = `WITH ${vn} FOR x IN OUTBOUND @startId @@eCol RETURN x._id`;
      var bindVars = {
        '@eCol': en,
        startId: vertex.A
      };
      var result = db._query(query, bindVars).toArray();
      assertEqual(result.length, 1);
      assertEqual(result, [null]);
    },

    testStartAtMissingVertex: function () {
      var query = `WITH ${vn} FOR x IN OUTBOUND @startId @@eCol RETURN x._id`;
      var bindVars = {
        '@eCol': en,
        startId: vn + '/missing'
      };
      var result = db._query(query, bindVars).toArray();
      assertEqual(result.length, 1);
      assertEqual(result, [vertex.B]);
    },

    testHopOverMissingVertex: function () {
      var query = `WITH ${vn} FOR x IN 2 OUTBOUND @startId @@eCol RETURN x._id`;
      var bindVars = {
        '@eCol': en,
        startId: vertex.A
      };
      var result = db._query(query, bindVars).toArray();
      assertEqual(result.length, 1);
      assertEqual(result, [vertex.B]);
    },

    testFilterOnMissingVertexNotTrue: function () {
      var filter = [
        'FILTER p.vertices[1].attribute == "missing"',
        'FILTER p.vertices[1].attribute > 12',
        'FILTER p.vertices[1] != null'
      ];
      for (var i = 0; i < filter.length; ++i) {
        var query = `WITH ${vn} FOR x, e, p IN 2 OUTBOUND @startId @@eCol ${filter[i]} RETURN x._id`;
        var bindVars = {
          '@eCol': en,
          startId: vertex.A
        };
        var result = AQL_EXECUTE(query, bindVars).json;
        assertEqual(result.length, 0, 'With opt: ', query);
        result = AQL_EXECUTE(query, bindVars, paramDisabled).json;
        assertEqual(result.length, 0, 'Without opt: ', query);
      }
    },

    testFilterOnMissingVertexTrue: function () {
      var filter = [
        'FILTER p.vertices[1].attribute != "missing"',
        'FILTER p.vertices[1].attribute < 12',
        'FILTER p.vertices[1] == null'
      ];
      for (var i = 0; i < filter.length; ++i) {
        var query = `WITH ${vn} FOR x, e, p IN 2 OUTBOUND @startId @@eCol ${filter[i]} RETURN x._id`;
        var bindVars = {
          '@eCol': en,
          startId: vertex.A
        };
        var result = AQL_EXECUTE(query, bindVars).json;
        assertEqual(result.length, 1, 'With opt: ', query);
        assertEqual(result, [vertex.B], 'With opt: ', query);
        result = AQL_EXECUTE(query, bindVars, paramDisabled).json;
        assertEqual(result.length, 1, 'Without opt: ', query);
        assertEqual(result, [vertex.B], 'Without opt: ', query);
      }
    },

    testQueryWithEmptyGraph: function () {
      var query = 'FOR x IN OUTBOUND "start/123" GRAPH @graph RETURN x';
      var emptyGN = 'UnitTestEmptyGraph';
      try {
        gm._drop(emptyGN);
      } catch (e) {
      }
      gm._create(emptyGN);
      var bindVars = {
        graph: emptyGN
      };
      try {
        db._query(query, bindVars);
        fail();
      } catch (e) {
        assertEqual(e.errorNum, errors.ERROR_GRAPH_EMPTY.code);
      }
      gm._drop(emptyGN);
    }
  };
}

function multiEdgeDirectionSuite() {
  const en2 = 'UnitTestEdgeCollection2';
  var ec2;

  return {

    setUpAll: function () {
      cleanup();
      db._drop(en2);

      vc = db._create(vn, { numberOfShards: 4 });
      ec = db._createEdgeCollection(en, { numberOfShards: 4 });
      ec2 = db._createEdgeCollection(en2, { numberOfShards: 4 });

      vertex.A = vc.save({ _key: 'A' })._id;
      vertex.B = vc.save({ _key: 'B' })._id;
      vertex.C = vc.save({ _key: 'C' })._id;
      vertex.D = vc.save({ _key: 'D' })._id;
      vertex.E = vc.save({ _key: 'E' })._id;

      vertex.F = vc.save({ _key: 'F' })._id;

      // F is always 2 hops away and only reachable with alternating
      // collections and directions

      ec.save(vertex.A, vertex.B, {});
      ec.save(vertex.C, vertex.A, {});
      ec2.save(vertex.A, vertex.D, {});
      ec2.save(vertex.E, vertex.A, {});

      ec2.save(vertex.F, vertex.B, {});
      ec2.save(vertex.C, vertex.F, {});

      ec.save(vertex.F, vertex.D, {});
      ec.save(vertex.E, vertex.F, {});
    },

    tearDownAll: function () {
      cleanup();
      db._drop(en2);
    },

    testOverrideOneDirection: function () {
      var queries = [
        {
          q1: `WITH ${vn} FOR x IN ANY @start @@ec1, INBOUND @@ec2 SORT x._key RETURN x._id`,
          q2: `WITH ${vn} FOR x IN ANY @start ${en}, INBOUND ${en2} SORT x._key RETURN x._id`,
          res: [vertex.B, vertex.C, vertex.E]
        },
        {
          q1: `WITH ${vn} FOR x IN ANY @start @@ec1, OUTBOUND @@ec2 SORT x._key RETURN x._id`,
          q2: `WITH ${vn} FOR x IN ANY @start ${en}, OUTBOUND ${en2} SORT x._key RETURN x._id`,
          res: [vertex.B, vertex.C, vertex.D]
        },
        {
          q1: `WITH ${vn} FOR x IN ANY @start INBOUND @@ec1, @@ec2 SORT x._key RETURN x._id`,
          q2: `WITH ${vn} FOR x IN ANY @start INBOUND ${en}, ${en2} SORT x._key RETURN x._id`,
          res: [vertex.C, vertex.D, vertex.E]
        },
        {
          q1: `WITH ${vn} FOR x IN ANY @start OUTBOUND @@ec1, @@ec2 SORT x._key RETURN x._id`,
          q2: `WITH ${vn} FOR x IN ANY @start OUTBOUND ${en}, ${en2} SORT x._key RETURN x._id`,
          res: [vertex.B, vertex.D, vertex.E]
        },
        {
          q1: `WITH ${vn} FOR x IN OUTBOUND @start INBOUND @@ec1, @@ec2 SORT x._key RETURN x._id`,
          q2: `WITH ${vn} FOR x IN OUTBOUND @start INBOUND ${en}, ${en2} SORT x._key RETURN x._id`,
          res: [vertex.C, vertex.D]
        },
        {
          q1: `WITH ${vn} FOR x IN OUTBOUND @start @@ec1, INBOUND @@ec2 SORT x._key RETURN x._id`,
          q2: `WITH ${vn} FOR x IN OUTBOUND @start ${en}, INBOUND ${en2} SORT x._key RETURN x._id`,
          res: [vertex.B, vertex.E]
        },
        {
          q1: `WITH ${vn} FOR x IN INBOUND @start @@ec1, OUTBOUND @@ec2 SORT x._key RETURN x._id`,
          q2: `WITH ${vn} FOR x IN INBOUND @start ${en}, OUTBOUND ${en2} SORT x._key RETURN x._id`,
          res: [vertex.C, vertex.D]
        },
        {
          q1: `WITH ${vn} FOR x IN INBOUND @start OUTBOUND @@ec1, @@ec2 SORT x._key RETURN x._id`,
          q2: `WITH ${vn} FOR x IN INBOUND @start OUTBOUND ${en}, ${en2} SORT x._key RETURN x._id`,
          res: [vertex.B, vertex.E]
        }
      ];

      var bindVars = {
        '@ec1': en,
        '@ec2': en2,
        start: vertex.A
      };
      var bindVars2 = {
        start: vertex.A
      };
      queries.forEach(function (item) {
        var result = db._query(item.q1, bindVars).toArray();
        assertEqual(result, item.res);
        result = db._query(item.q2, bindVars2).toArray();
        assertEqual(result, item.res);
      });
    },

    testDuplicationCollections: function () {
      var queries = [
        [`WITH ${vn} FOR x IN ANY @start @@ec, INBOUND @@ec RETURN x`, false],
        [`WITH ${vn} FOR x IN ANY @start @@ec, OUTBOUND @@ec RETURN x`, false],
        [`WITH ${vn} FOR x IN ANY @start @@ec, ANY @@ec RETURN x`, true],
        [`WITH ${vn} FOR x IN INBOUND @start @@ec, INBOUND @@ec RETURN x`, true],
        [`WITH ${vn} FOR x IN INBOUND @start @@ec, OUTBOUND @@ec RETURN x`, false],
        [`WITH ${vn} FOR x IN INBOUND @start @@ec, ANY @@ec RETURN x`, false],
        [`WITH ${vn} FOR x IN OUTBOUND @start @@ec, INBOUND @@ec RETURN x`, false],
        [`WITH ${vn} FOR x IN OUTBOUND @start @@ec, OUTBOUND @@ec RETURN x`, true],
        [`WITH ${vn} FOR x IN OUTBOUND @start @@ec, ANY @@ec RETURN x`, false]
      ];

      var bindVars = {
        '@ec': en,
        start: vertex.A
      };
      queries.forEach(function (query) {
        if (query[1]) {
          // should work
          db._query(query[0], bindVars).toArray();
        } else {
          // should fail
          try {
            db._query(query[0], bindVars).toArray();
            fail();
          } catch (e) {
            assertEqual(e.errorNum, errors.ERROR_ARANGO_COLLECTION_TYPE_INVALID.code);
          }
        }
      });
    }
  };
}

function subQuerySuite() {
  const gn = 'UnitTestGraph';
  return {

    /*
     * Graph under Test:
     *
     * A -> B -> [B1, B2, B3, B4, B5]
     *   \> C -> [C1, C2, C3, C4, C5]
     *   \> D -> [D1, D2, D3, D4, D5]
     *
     */
    setUpAll: function () {
      cleanup();
      vc = db._create(vn, { numberOfShards: 4 });
      ec = db._createEdgeCollection(en, { numberOfShards: 4 });

      try {
        gm._drop(gn);
      } catch (e) {
        // It is expected that this graph does not exist.
      }

      gm._create(gn, [gm._relation(en, vn, vn)]);

      vertex.A = vc.save({ _key: 'A' })._id;
      vertex.B = vc.save({ _key: 'B' })._id;
      vertex.C = vc.save({ _key: 'C' })._id;
      vertex.D = vc.save({ _key: 'D' })._id;

      vertex.B1 = vc.save({ _key: 'B1', value: 1 })._id;
      vertex.B2 = vc.save({ _key: 'B2', value: 2 })._id;
      vertex.B3 = vc.save({ _key: 'B3', value: 3 })._id;
      vertex.B4 = vc.save({ _key: 'B4', value: 4 })._id;
      vertex.B5 = vc.save({ _key: 'B5', value: 5 })._id;

      vertex.C1 = vc.save({ _key: 'C1', value: 1 })._id;
      vertex.C2 = vc.save({ _key: 'C2', value: 2 })._id;
      vertex.C3 = vc.save({ _key: 'C3', value: 3 })._id;
      vertex.C4 = vc.save({ _key: 'C4', value: 4 })._id;
      vertex.C5 = vc.save({ _key: 'C5', value: 5 })._id;

      vertex.D1 = vc.save({ _key: 'D1', value: 1 })._id;
      vertex.D2 = vc.save({ _key: 'D2', value: 2 })._id;
      vertex.D3 = vc.save({ _key: 'D3', value: 3 })._id;
      vertex.D4 = vc.save({ _key: 'D4', value: 4 })._id;
      vertex.D5 = vc.save({ _key: 'D5', value: 5 })._id;

      ec.save(vertex.A, vertex.B, {});
      ec.save(vertex.A, vertex.C, {});
      ec.save(vertex.A, vertex.D, {});

      ec.save(vertex.B, vertex.B1, {});
      ec.save(vertex.B, vertex.B2, {});
      ec.save(vertex.B, vertex.B3, {});
      ec.save(vertex.B, vertex.B4, {});
      ec.save(vertex.B, vertex.B5, {});

      ec.save(vertex.C, vertex.C1, {});
      ec.save(vertex.C, vertex.C2, {});
      ec.save(vertex.C, vertex.C3, {});
      ec.save(vertex.C, vertex.C4, {});
      ec.save(vertex.C, vertex.C5, {});

      ec.save(vertex.D, vertex.D1, {});
      ec.save(vertex.D, vertex.D2, {});
      ec.save(vertex.D, vertex.D3, {});
      ec.save(vertex.D, vertex.D4, {});
      ec.save(vertex.D, vertex.D5, {});
    },

    tearDownAll: function () {
      try {
        gm._drop(gn);
      } catch (e) {
        // Just in case the test leaves an invalid state.
      }
      cleanup();
    },

    // The test is that the traversal in subquery has more then LIMIT many
    // results. In case of a bug the cursor of the traversal is reused for the second
    // iteration as well and does not reset.
    testSubQueryFixedStart: function () {
      var q = `WITH ${vn}
      FOR v IN OUTBOUND '${vertex.A}' ${en}
      SORT v._key
      LET sub = (
        FOR t IN OUTBOUND '${vertex.B}' ${en}
        SORT t.value
        LIMIT 3
        RETURN t
      )
      RETURN sub`;
      var actual = db._query(q).toArray();
      assertEqual(actual.length, 3); // On the top level we find 3 results
      for (var i = 0; i < actual.length; ++i) {
        var current = actual[i];
        assertEqual(current.length, 3); // Check for limit
        // All should be connected to B!
        assertEqual(current[0]._id, vertex.B1);
        assertEqual(current[1]._id, vertex.B2);
        assertEqual(current[2]._id, vertex.B3);
      }
    },

    // The test is that the traversal in subquery has more then LIMIT many
    // results. In case of a bug the cursor of the traversal is reused for the second
    // iteration as well and does not reset.
    testSubQueryDynamicStart: function () {
      var q = `WITH ${vn}
      FOR v IN OUTBOUND '${vertex.A}' ${en}
      SORT v._key
      LET sub = (
        FOR t IN OUTBOUND v ${en}
        SORT t.value
        LIMIT 3
        RETURN t
      )
      RETURN sub`;
      var actual = db._query(q).toArray();
      assertEqual(actual.length, 3); // On the top level we find 3 results
      for (var i = 0; i < actual.length; ++i) {
        assertEqual(actual[i].length, 3); // Check for limit
      }
      var current = actual[0];
      // All should be connected to B!
      assertEqual(current[0]._id, vertex.B1);
      assertEqual(current[1]._id, vertex.B2);
      assertEqual(current[2]._id, vertex.B3);

      current = actual[1];
      // All should be connected to C!
      assertEqual(current[0]._id, vertex.C1);
      assertEqual(current[1]._id, vertex.C2);
      assertEqual(current[2]._id, vertex.C3);

      current = actual[2];
      // All should be connected to D!
      assertEqual(current[0]._id, vertex.D1);
      assertEqual(current[1]._id, vertex.D2);
      assertEqual(current[2]._id, vertex.D3);
    }
  };
}

function optionsSuite() {
  const gn = 'UnitTestGraph';

  return {
    setUp: function () {
      cleanup();
      vc = db._create(vn, { numberOfShards: 4 });
      ec = db._createEdgeCollection(en, { numberOfShards: 4 });
      try {
        gm._drop(gn);
      } catch (e) {
        // It is expected that this graph does not exist.
      }

      gm._create(gn, [gm._relation(en, vn, vn)]);
    },

    tearDown: function () {
      try {
        gm._drop(gn);
      } catch (e) {
        // It is expected that this graph does not exist.
      }
      cleanup();
    },

    testEdgeUniquenessPath: function () {
      var start = vc.save({ _key: 's' })._id;
      var a = vc.save({ _key: 'a' })._id;
      var b = vc.save({ _key: 'b' })._id;
      var c = vc.save({ _key: 'c' })._id;
      var d = vc.save({ _key: 'd' })._id;
      ec.save(start, a, {});
      ec.save(a, b, {});
      ec.save(b, c, {});
      ec.save(c, a, {});
      ec.save(a, d, {});
      var cursor = db._query(
        `WITH ${vn}
        FOR v IN 1..10 OUTBOUND '${start}' ${en} OPTIONS {uniqueEdges: 'path'}
        SORT v._key
        RETURN v`).toArray();
      // We expect to get s->a->b->c->a->d
      // and s->a->d
      // But not s->a->b->c->a->b->*
      // And not to continue at a again
      assertEqual(cursor.length, 6);
      assertEqual(cursor[0]._id, a); // We start with a
      assertEqual(cursor[1]._id, a); // We somehow return to a
      assertEqual(cursor[2]._id, b); // We once find b
      assertEqual(cursor[3]._id, c); // And once c
      assertEqual(cursor[4]._id, d); // We once find d on short path
      assertEqual(cursor[5]._id, d); // And find d on long path
    },

    testEdgeUniquenessGlobal: function () {
      var start = vc.save({ _key: 's' })._id;
      try {
        db._query(
          `WITH ${vn}
          FOR v IN 1..10 OUTBOUND '${start}' ${en} OPTIONS {uniqueEdges: 'global'}
          SORT v._key
          RETURN v`).toArray();
        fail();
      } catch (e) {
        assertEqual(e.errorNum, errors.ERROR_BAD_PARAMETER.code, 'We expect a bad parameter');
      }
    },

    testEdgeUniquenessNone: function () {
      var start = vc.save({ _key: 's' })._id;
      var a = vc.save({ _key: 'a' })._id;
      var b = vc.save({ _key: 'b' })._id;
      var c = vc.save({ _key: 'c' })._id;
      var d = vc.save({ _key: 'd' })._id;
      ec.save(start, a, {});
      ec.save(a, b, {});
      ec.save(b, c, {});
      ec.save(c, a, {});
      ec.save(a, d, {});
      var cursor = db._query(
        `WITH ${vn}
        FOR v IN 1..10 OUTBOUND '${start}' ${en} OPTIONS {uniqueEdges: 'none'}
        SORT v._key
        RETURN v`).toArray();
      // We expect to get s->a->d
      // We expect to get s->a->b->c->a->d
      // We expect to get s->a->b->c->a->b->c->a->d
      // We expect to get s->a->b->c->a->b->c->a->b->c->a
      assertEqual(cursor.length, 13);
      assertEqual(cursor[0]._id, a); // We start with a
      assertEqual(cursor[1]._id, a); // We somehow return to a
      assertEqual(cursor[2]._id, a); // We somehow return to a again
      assertEqual(cursor[3]._id, a); // We somehow return to a again
      assertEqual(cursor[4]._id, b); // We once find b
      assertEqual(cursor[5]._id, b); // We find b again
      assertEqual(cursor[6]._id, b); // And b again
      assertEqual(cursor[7]._id, c); // And once c
      assertEqual(cursor[8]._id, c); // We find c again
      assertEqual(cursor[9]._id, c); // And c again
      assertEqual(cursor[10]._id, d); // Short Path d
      assertEqual(cursor[11]._id, d); // One Loop d
      assertEqual(cursor[12]._id, d); // Second Loop d
    },

    testVertexUniquenessNone: function () {
      var start = vc.save({ _key: 's' })._id;
      var a = vc.save({ _key: 'a' })._id;
      var b = vc.save({ _key: 'b' })._id;
      var c = vc.save({ _key: 'c' })._id;
      var d = vc.save({ _key: 'd' })._id;
      ec.save(start, a, {});
      ec.save(a, b, {});
      ec.save(b, c, {});
      ec.save(c, a, {});
      ec.save(a, d, {});
      var cursor = db._query(
        `WITH ${vn}
        FOR v IN 1..10 OUTBOUND '${start}' ${en} OPTIONS {uniqueVertices: 'none'}
        SORT v._key
        RETURN v`).toArray();
      // We expect to get s->a->b->c->a->d
      // and s->a->d
      // But not s->a->b->c->a->b->*
      // And not to continue at a again

      // Default edge Uniqueness is path
      assertEqual(cursor.length, 6);
      assertEqual(cursor[0]._id, a); // We start with a
      assertEqual(cursor[1]._id, a); // We somehow return to a
      assertEqual(cursor[2]._id, b); // We once find b
      assertEqual(cursor[3]._id, c); // And once c
      assertEqual(cursor[4]._id, d); // We once find d on short path
      assertEqual(cursor[5]._id, d); // And find d on long path
    },

    testVertexUniquenessGlobalDepthFirst: function () {
      var start = vc.save({ _key: 's' })._id;
      try {
        db._query(
          `WITH ${vn}
          FOR v IN 1..10 OUTBOUND '${start}' ${en} OPTIONS {uniqueVertices: 'global'}
          SORT v._key
          RETURN v`).toArray();
        fail();
      } catch (e) {
        assertEqual(e.errorNum, errors.ERROR_BAD_PARAMETER.code, 'We expect a bad parameter');
      }
    },

    testVertexUniquenessPath: function () {
      var start = vc.save({ _key: 's' })._id;
      var a = vc.save({ _key: 'a' })._id;
      var b = vc.save({ _key: 'b' })._id;
      var c = vc.save({ _key: 'c' })._id;
      ec.save(start, a, {});
      ec.save(a, b, {});
      ec.save(a, a, {});
      ec.save(b, c, {});
      ec.save(b, a, {});
      ec.save(c, a, {});
      var cursor = db._query(
        `WITH ${vn}
        FOR v IN 1..10 OUTBOUND '${start}' ${en} OPTIONS {uniqueVertices: 'path'}
        SORT v._key
        RETURN v`).toArray();
      // We expect to get s->a->b->c
      // But not s->a->a*
      // But not s->a->b->a*
      // But not s->a->b->c->a*
      assertEqual(cursor.length, 3);
      assertEqual(cursor[0]._id, a); // We start with a
      assertEqual(cursor[1]._id, b); // We find a->b
      assertEqual(cursor[2]._id, c); // We find a->b->c
    }
  };
}

function optimizeQuantifierSuite() {
  /* ******************************
   * Graph under test
   * C <-+             +-> F
   *     |             |
   *     +-B<---A--->E-+
   *     |             |
   * D <-+             +-> G
   *
   *
   * Left side has foo: true, right foo: false
   * Top has bar: true, bottom bar: false.
   * A,B,E has bar: true
   * A has foo: true
   * Edges have foo and bar like their target
   *******************************/

  const gn = 'UnitTestGraph';
  let vertices = {};
  let edges = {};

  return {
    setUpAll: function () {
      cleanup();
      vc = db._create(vn, { numberOfShards: 4 });
      ec = db._createEdgeCollection(en, { numberOfShards: 4 });
      vertices.A = vc.save({ _key: 'A', foo: true, bar: true })._id;
      vertices.B = vc.save({ _key: 'B', foo: true, bar: true })._id;
      vertices.C = vc.save({ _key: 'C', foo: true, bar: true })._id;
      vertices.D = vc.save({ _key: 'D', foo: true, bar: false })._id;
      vertices.E = vc.save({ _key: 'E', foo: false, bar: true })._id;
      vertices.F = vc.save({ _key: 'F', foo: false, bar: true })._id;
      vertices.G = vc.save({ _key: 'G', foo: false, bar: false })._id;

      edges.AB = ec.save({ _key: 'AB', _from: vertices.A, _to: vertices.B, foo: true, bar: true })._id;
      edges.BC = ec.save({ _key: 'BC', _from: vertices.B, _to: vertices.C, foo: true, bar: true })._id;
      edges.BD = ec.save({ _key: 'BD', _from: vertices.B, _to: vertices.D, foo: true, bar: false })._id;
      edges.AE = ec.save({ _key: 'AE', _from: vertices.A, _to: vertices.E, foo: false, bar: true })._id;
      edges.EF = ec.save({ _key: 'EF', _from: vertices.E, _to: vertices.F, foo: false, bar: true })._id;
      edges.EG = ec.save({ _key: 'EG', _from: vertices.E, _to: vertices.G, foo: false, bar: false })._id;

      try {
        gm._drop(gn);
      } catch (e) {
        // It is expected that this graph does not exist.
      }

      gm._create(gn, [gm._relation(en, vn, vn)]);
    },

    tearDownAll: function () {
      try {
        gm._drop(gn);
      } catch (e) {
        // It is expected that this graph does not exist.
      }
      cleanup();
    },

    testAllVerticesSingle: function () {
      let query = `
      FOR v, e, p IN 0..2 OUTBOUND '${vertices.A}' GRAPH '${gn}'
      FILTER p.vertices[*].foo ALL == true
      SORT v._key
      RETURN v._id
      `;
      let cursor = db._query(query);
      assertEqual(cursor.count(), 4);
      let result = cursor.toArray();
      assertEqual(result, [vertices.A, vertices.B, vertices.C, vertices.D]);

      let stats = cursor.getExtra().stats;
      assertEqual(stats.scannedFull, 0);
      if (isCluster) {
        if (mmfilesEngine) {
          assertTrue(stats.scannedIndex <= 9);
        } else {
          assertTrue(stats.scannedIndex <= 5);
        }
      } else {
        // With traverser-read-cache
        // assertEqual(stats.scannedIndex, 9);

        // Without traverser-read-cache
        // TODO Check for Optimization
        // assertEqual(stats.scannedIndex, 23);
        assertTrue(stats.scannedIndex <= 22);
        /*
          if(mmfilesEngine){
          assertEqual(stats.scannedIndex, 22);
          } else {
          assertEqual(stats.scannedIndex, 18);
          }
        */
      }
      assertEqual(stats.filtered, 1);

      query = `
      FOR v, e, p IN 0..2 OUTBOUND '${vertices.A}' GRAPH '${gn}'
      FILTER p.vertices[*].foo ALL == false
      SORT v._key
      RETURN v._id
      `;
      cursor = db._query(query);
      assertEqual(cursor.count(), 0);

      stats = cursor.getExtra().stats;
      assertEqual(stats.scannedFull, 0);
      assertEqual(stats.scannedIndex, 1);
      assertEqual(stats.filtered, 1);
    },

    testAllEdgesSingle: function () {
      let query = `
      FOR v, e, p IN 0..2 OUTBOUND '${vertices.A}' GRAPH '${gn}'
      FILTER p.edges[*].foo ALL == true
      SORT v._key
      RETURN v._id
      `;
      let cursor = db._query(query);
      assertEqual(cursor.count(), 4);
      let result = cursor.toArray();
      assertEqual(result, [vertices.A, vertices.B, vertices.C, vertices.D]);

      let stats = cursor.getExtra().stats;
      assertEqual(stats.scannedFull, 0);
      if (isCluster) {
        if (mmfilesEngine) {
          assertTrue(stats.scannedIndex <= 8);
        } else {
          assertTrue(stats.scannedIndex <= 4);
        }
      } else {
        // With traverser-read-cache
        // assertEqual(stats.scannedIndex, 8);

        // TODO Check for Optimization
        // Without traverser-read-cache
        // assertEqual(stats.scannedIndex, 18);
        assertTrue(stats.scannedIndex <= 17);
        /*
          if(mmfilesEngine){
          assertEqual(stats.scannedIndex, 17);
          } else {
          assertEqual(stats.scannedIndex, 13);
          }
        */
      }
      assertTrue(stats.filtered <= 2);

      query = `
      FOR v, e, p IN 0..2 OUTBOUND '${vertices.A}' GRAPH '${gn}'
      FILTER p.edges[*].foo ALL == false
      SORT v._key
      RETURN v._id
      `;
      cursor = db._query(query);
      assertEqual(cursor.count(), 4);
      result = cursor.toArray();
      assertEqual(result, [vertices.A, vertices.E, vertices.F, vertices.G]);

      stats = cursor.getExtra().stats;
      assertEqual(stats.scannedFull, 0);
      if (isCluster) {
        if (mmfilesEngine) {
          assertTrue(stats.scannedIndex <= 8);
        } else {
          assertTrue(stats.scannedIndex <= 4);
        }
      } else {
        // With traverser-read-cache
        // assertEqual(stats.scannedIndex, 8);

        // Without traverser-read-cache
        // assertEqual(stats.scannedIndex, 18);
        assertTrue(stats.scannedIndex <= 17);
        /*
          if(mmfilesEngine){
          assertEqual(stats.scannedIndex, 17);
          } else {
          assertEqual(stats.scannedIndex, 13);
          }
        */
      }
      assertTrue(stats.filtered <= 2);
    },

    testNoneVerticesSingle: function () {
      let query = `
      FOR v, e, p IN 0..2 OUTBOUND '${vertices.A}' GRAPH '${gn}'
      FILTER p.vertices[*].foo NONE == false
      SORT v._key
      RETURN v._id
      `;
      let cursor = db._query(query);
      assertEqual(cursor.count(), 4);
      let result = cursor.toArray();
      assertEqual(result, [vertices.A, vertices.B, vertices.C, vertices.D]);

      let stats = cursor.getExtra().stats;
      assertEqual(stats.scannedFull, 0);
      if (isCluster) {
        if (mmfilesEngine) {
          assertTrue(stats.scannedIndex <= 9);
        } else {
          assertTrue(stats.scannedIndex <= 5);
        }
      } else {
        // With traverser-read-cache
        // assertEqual(stats.scannedIndex, 9);

        // Without traverser-read-cache
        // TODO Check for Optimization
        // assertEqual(stats.scannedIndex, 23);
        assertTrue(stats.scannedIndex <= 22);
        /*
          if(mmfilesEngine){
          assertEqual(stats.scannedIndex, 22);
          } else {
          assertEqual(stats.scannedIndex, 18);
          }
        */
      }
      assertEqual(stats.filtered, 1);

      query = `
      FOR v, e, p IN 0..2 OUTBOUND '${vertices.A}' GRAPH '${gn}'
      FILTER p.vertices[*].foo NONE == true
      SORT v._key
      RETURN v._id
      `;
      cursor = db._query(query);
      assertEqual(cursor.count(), 0);

      stats = cursor.getExtra().stats;
      assertEqual(stats.scannedFull, 0);
      assertEqual(stats.scannedIndex, 1);
      assertEqual(stats.filtered, 1);
    },

    testNoneEdgesSingle: function () {
      let query = `
      FOR v, e, p IN 0..2 OUTBOUND '${vertices.A}' GRAPH '${gn}'
      FILTER p.edges[*].foo NONE == false
      SORT v._key
      RETURN v._id
      `;
      let cursor = db._query(query);
      assertEqual(cursor.count(), 4);
      let result = cursor.toArray();
      assertEqual(result, [vertices.A, vertices.B, vertices.C, vertices.D]);

      let stats = cursor.getExtra().stats;
      assertEqual(stats.scannedFull, 0);
      if (isCluster) {
        if (mmfilesEngine) {
          assertTrue(stats.scannedIndex <= 8);
        } else {
          assertTrue(stats.scannedIndex <= 4);
        }
      } else {
        // With traverser-read-cache
        // assertEqual(stats.scannedIndex, 8);

        // Without traverser-read-cache
        // assertEqual(stats.scannedIndex, 18);
        assertTrue(stats.scannedIndex <= 17);
        /*
          if(mmfilesEngine){
          assertEqual(stats.scannedIndex, 17);
          } else {
          assertEqual(stats.scannedIndex, 13);
          }
        */
      }
      assertEqual(stats.filtered, 1);

      query = `
      FOR v, e, p IN 0..2 OUTBOUND '${vertices.A}' GRAPH '${gn}'
      FILTER p.edges[*].foo NONE == true
      SORT v._key
      RETURN v._id
      `;
      cursor = db._query(query);
      assertEqual(cursor.count(), 4);
      result = cursor.toArray();
      assertEqual(result, [vertices.A, vertices.E, vertices.F, vertices.G]);

      stats = cursor.getExtra().stats;
      assertEqual(stats.scannedFull, 0);
      if (isCluster) {
        if (mmfilesEngine) {
          assertTrue(stats.scannedIndex <= 8);
        } else {
          assertTrue(stats.scannedIndex <= 4);
        }
      } else {
        // With traverser-read-cache
        // assertEqual(stats.scannedIndex, 8);

        // Without traverser-read-cache
        // TODO Check for Optimization
        assertTrue(stats.scannedIndex <= 17);
        /*
          if(mmfilesEngine){
          assertEqual(stats.scannedIndex, 17);
          } else {
          assertEqual(stats.scannedIndex, 13);
          }
        */
      }
      assertEqual(stats.filtered, 1);
    },

    testAllVerticesMultiple: function () {
      let query = `
      FOR v, e, p IN 0..2 OUTBOUND '${vertices.A}' GRAPH '${gn}'
      FILTER p.vertices[*].foo ALL == true
      FILTER p.vertices[*].bar ALL == true
      SORT v._key
      RETURN v._id
      `;
      let cursor = db._query(query);
      assertEqual(cursor.count(), 3);
      let result = cursor.toArray();
      assertEqual(result, [vertices.A, vertices.B, vertices.C]);

      let stats = cursor.getExtra().stats;
      assertEqual(stats.scannedFull, 0);
      if (isCluster) {
        if (mmfilesEngine) {
          assertTrue(stats.scannedIndex <= 9);
        } else {
          assertTrue(stats.scannedIndex <= 5);
        }
      } else {
        // With traverser-read-cache
        // assertEqual(stats.scannedIndex, 9);

        // Without traverser-read-cache
        // assertEqual(stats.scannedIndex, 17);
        assertTrue(stats.scannedIndex <= 18);
        /*
          if(mmfilesEngine){
          assertEqual(stats.scannedIndex, 18);
          } else {
          assertEqual(stats.scannedIndex, 14);
          }
        */
      }
      assertEqual(stats.filtered, 2);
    },

    testAllEdgesMultiple: function () {
      let query = `
      FOR v, e, p IN 0..2 OUTBOUND '${vertices.A}' GRAPH '${gn}'
      FILTER p.edges[*].foo ALL == true
      FILTER p.edges[*].bar ALL == true
      SORT v._key
      RETURN v._id
      `;
      let cursor = db._query(query);
      assertEqual(cursor.count(), 3);
      let result = cursor.toArray();
      assertEqual(result, [vertices.A, vertices.B, vertices.C]);

      let stats = cursor.getExtra().stats;
      assertEqual(stats.scannedFull, 0);
      if (isCluster) {
        if (mmfilesEngine) {
          assertTrue(stats.scannedIndex <= 7);
        } else {
          assertTrue(stats.scannedIndex <= 3);
        }
      } else {
        // With activated traverser-read-cache:
        // assertEqual(stats.scannedIndex, 7);

        // Without traverser-read-cache
        // assertEqual(stats.scannedIndex, 12);
        assertTrue(stats.scannedIndex <= 13);
        /*
          if(mmfilesEngine){
          assertEqual(stats.scannedIndex, 13);
          } else {
          assertEqual(stats.scannedIndex, 9);
          }
        */
      }
      assertTrue(stats.filtered <= 3);
    },

    testAllNoneVerticesMultiple: function () {
      let query = `
      FOR v, e, p IN 0..2 OUTBOUND '${vertices.A}' GRAPH '${gn}'
      FILTER p.vertices[*].foo ALL == true
      FILTER p.vertices[*].bar NONE == false
      SORT v._key
      RETURN v._id
      `;
      let cursor = db._query(query);
      assertEqual(cursor.count(), 3);
      let result = cursor.toArray();
      assertEqual(result, [vertices.A, vertices.B, vertices.C]);

      let stats = cursor.getExtra().stats;
      assertEqual(stats.scannedFull, 0);
      if (isCluster) {
        if (mmfilesEngine) {
          assertTrue(stats.scannedIndex <= 9);
        } else {
          assertTrue(stats.scannedIndex <= 5);
        }
      } else {
        // With traverser-read-cache
        // assertEqual(stats.scannedIndex, 9);

        // Without traverser-read-cache
        // TODO Check for Optimization
        // assertEqual(stats.scannedIndex, 17);
        assertTrue(stats.scannedIndex <= 18);
        /*
          if(mmfilesEngine){
          assertEqual(stats.scannedIndex, 18);
          } else {
          assertEqual(stats.scannedIndex, 14);
          }
        */
      }
      assertEqual(stats.filtered, 2);
    },

    testAllNoneEdgesMultiple: function () {
      let query = `
      FOR v, e, p IN 0..2 OUTBOUND '${vertices.A}' GRAPH '${gn}'
      FILTER p.edges[*].foo ALL == true
      FILTER p.edges[*].bar NONE == false
      SORT v._key
      RETURN v._id
      `;
      let cursor = db._query(query);
      assertEqual(cursor.count(), 3);
      let result = cursor.toArray();
      assertEqual(result, [vertices.A, vertices.B, vertices.C]);

      let stats = cursor.getExtra().stats;
      assertEqual(stats.scannedFull, 0);
      if (isCluster) {
        if (mmfilesEngine) {
          assertTrue(stats.scannedIndex <= 7);
        } else {
          assertTrue(stats.scannedIndex <= 3);
        }
      } else {
        // With activated traverser-read-cache:
        // assertEqual(stats.scannedIndex, 7);

        // Without traverser-read-cache
        // TODO Check for Optimization
        // assertEqual(stats.scannedIndex, 12);
        assertTrue(stats.scannedIndex <= 13);
        /*
          if(mmfilesEngine){
          assertEqual(stats.scannedIndex, 13);
          } else {
          assertEqual(stats.scannedIndex, 9);
          }
        */
      }
      assertTrue(stats.filtered <= 3);
    },

    testAllVerticesDepth: function () {
      let query = `
      FOR v, e, p IN 0..2 OUTBOUND '${vertices.A}' GRAPH '${gn}'
      FILTER p.vertices[*].foo ALL == true
      FILTER p.vertices[2].bar == false
      SORT v._key
      RETURN v._id
      `;
      let cursor = db._query(query);
      assertEqual(cursor.count(), 1);
      let result = cursor.toArray();
      assertEqual(result, [vertices.D]);

      let stats = cursor.getExtra().stats;
      assertEqual(stats.scannedFull, 0);
      if (isCluster) {
        if (mmfilesEngine) {
          assertTrue(stats.scannedIndex <= 9);
        } else {
          assertTrue(stats.scannedIndex <= 5);
        }
      } else {
        // With activated traverser-read-cache:
        // assertEqual(stats.scannedIndex, 9);

        // Without traverser-read-cache
        // TODO Check for Optimization
        // assertEqual(stats.scannedIndex, 17);
        assertTrue(stats.scannedIndex <= 18);
        /*
          if(mmfilesEngine){
          assertEqual(stats.scannedIndex, 18);
          } else {
          assertEqual(stats.scannedIndex, 14);
          }
        */
      }
      assertTrue(stats.filtered <= 4);
    },

    testAllEdgesAndDepth: function () {
      let query = `
      FOR v, e, p IN 0..2 OUTBOUND '${vertices.A}' GRAPH '${gn}'
      FILTER p.edges[*].foo ALL == true
      FILTER p.edges[1].bar == false
      SORT v._key
      RETURN v._id
      `;
      let cursor = db._query(query);
      assertEqual(cursor.count(), 1);
      let result = cursor.toArray();
      assertEqual(result, [vertices.D]);

      let stats = cursor.getExtra().stats;
      assertEqual(stats.scannedFull, 0);
      if (isCluster) {
        if (mmfilesEngine) {
          assertTrue(stats.scannedIndex <= 7);
        } else {
          assertTrue(stats.scannedIndex <= 3);
        }
      } else {
        // With activated traverser-read-cache:
        // assertEqual(stats.scannedIndex, 7);

        // Without traverser-read-cache
        // TODO Check for Optimization
        // assertEqual(stats.scannedIndex, 12);
        assertTrue(stats.scannedIndex <= 13);
        /*
          if(mmfilesEngine){
          assertEqual(stats.scannedIndex, 13);
          } else {
          assertEqual(stats.scannedIndex, 9);
          }
        */
      }
      assertTrue(stats.filtered <= 4);
    }
  };
}

function optimizeNonVertexCentricIndexesSuite() {
  let explain = function (query, params) {
    return AQL_EXPLAIN(query, params, { optimizer: { rules: ['+all'] } });
  };

  let vertices = {};
  let edges = {};

  return {
    setUpAll: () => {
      cleanup();
      vc = db._create(vn, { numberOfShards: 4 });
      ec = db._createEdgeCollection(en, { numberOfShards: 4 });
      vertices.A = vc.save({ _key: 'A' })._id;
      vertices.B = vc.save({ _key: 'B' })._id;
      vertices.C = vc.save({ _key: 'C' })._id;
      vertices.D = vc.save({ _key: 'D' })._id;
      vertices.E = vc.save({ _key: 'E' })._id;
      vertices.F = vc.save({ _key: 'F' })._id;
      vertices.G = vc.save({ _key: 'G' })._id;

      vertices.FOO = vc.save({ _key: 'FOO' })._id;
      vertices.BAR = vc.save({ _key: 'BAR' })._id;

      edges.AB = ec.save({ _key: 'AB', _from: vertices.A, _to: vertices.B, foo: 'A', bar: true })._id;
      edges.BC = ec.save({ _key: 'BC', _from: vertices.B, _to: vertices.C, foo: 'B', bar: true })._id;
      edges.BD = ec.save({ _key: 'BD', _from: vertices.B, _to: vertices.D, foo: 'C', bar: false })._id;
      edges.AE = ec.save({ _key: 'AE', _from: vertices.A, _to: vertices.E, foo: 'D', bar: true })._id;
      edges.EF = ec.save({ _key: 'EF', _from: vertices.E, _to: vertices.F, foo: 'E', bar: true })._id;
      edges.EG = ec.save({ _key: 'EG', _from: vertices.E, _to: vertices.G, foo: 'F', bar: false })._id;

      // Adding these edges to make the estimate for the edge-index extremly bad
      let badEdges = [];
      for (let j = 0; j < 1000; ++j) {
        badEdges.push({ _from: vertices.FOO, _to: vertices.BAR, foo: 'foo' + j, bar: j });
      }
      ec.save(badEdges);
    },

    tearDownAll: cleanup,

    tearDown: () => {
      // After each test get rid of all superflous indexes.
      var idxs = db[en].getIndexes();
      for (let i = 2; i < idxs.length; ++i) {
        db[en].dropIndex(idxs[i].id);
      }
    },

    testUniqueHashIndex: () => {
      var idx = db[en].ensureIndex({ type: 'hash', fields: ['foo'], unique: true, sparse: false });
      // This index is assumed to be better than edge-index, but does not contain _from/_to
      let q = `FOR v,e,p IN OUTBOUND '${vertices.A}' ${en}
      FILTER p.edges[0].foo == 'A'
      RETURN v._id`;
      internal.waitForEstimatorSync(); // make sure estimates are consistent

      let exp = explain(q, {}).plan.nodes.filter(node => { return node.type === 'TraversalNode'; });
      assertEqual(1, exp.length);
      // Check if we did use the hash index on level 0
      let indexes = exp[0].indexes;
      let found = indexes.levels['0'];
      assertEqual(1, found.length);
      found = found[0];
      assertEqual(idx.type, found.type);
      assertEqual(idx.fields, found.fields);

      let result = db._query(q).toArray();
      assertEqual(result[0], vertices.B);
    },

    testUniqueSkiplistIndex: () => {
      var idx = db[en].ensureIndex({ type: 'skiplist', fields: ['foo'], unique: true, sparse: false });
      // This index is assumed to be better than edge-index, but does not contain _from/_to
      let q = `FOR v,e,p IN OUTBOUND '${vertices.A}' ${en}
      FILTER p.edges[0].foo == 'A'
      RETURN v._id`;
      internal.waitForEstimatorSync(); // make sure estimates are consistent

      let exp = explain(q, {}).plan.nodes.filter(node => { return node.type === 'TraversalNode'; });
      assertEqual(1, exp.length);
      // Check if we did use the hash index on level 0
      let indexes = exp[0].indexes;
      let found = indexes.levels['0'];
      assertEqual(1, found.length);
      found = found[0];
      assertEqual(idx.type, found.type);
      assertEqual(idx.fields, found.fields);

      let result = db._query(q).toArray();
      assertEqual(result[0], vertices.B);
    },

    testAllUniqueHashIndex: () => {
      var idx = db[en].ensureIndex({ type: 'hash', fields: ['foo'], unique: true, sparse: false });
      // This index is assumed to be better than edge-index, but does not contain _from/_to
      let q = `FOR v,e,p IN OUTBOUND '${vertices.A}' ${en}
      FILTER p.edges[*].foo ALL == 'A'
      RETURN v._id`;

      let exp = explain(q, {}).plan.nodes.filter(node => { return node.type === 'TraversalNode'; });
      assertEqual(1, exp.length);
      // Check if we did use the hash index on level 0
      let indexes = exp[0].indexes;
      let found = indexes.base;
      assertEqual(1, found.length);
      found = found[0];
      assertEqual(idx.type, found.type);
      assertEqual(idx.fields, found.fields);

      let result = db._query(q).toArray();
      assertEqual(result[0], vertices.B);
    },

    testAllUniqueSkiplistIndex: () => {
      var idx = db[en].ensureIndex({ type: 'skiplist', fields: ['foo'], unique: true, sparse: false });
      // This index is assumed to be better than edge-index, but does not contain _from/_to
      let q = `FOR v,e,p IN OUTBOUND '${vertices.A}' ${en}
      FILTER p.edges[*].foo ALL == 'A'
      RETURN v._id`;

      let exp = explain(q, {}).plan.nodes.filter(node => { return node.type === 'TraversalNode'; });
      assertEqual(1, exp.length);
      // Check if we did use the hash index on level 0
      let indexes = exp[0].indexes;
      let found = indexes.base;
      assertEqual(1, found.length);
      found = found[0];
      assertEqual(idx.type, found.type);
      assertEqual(idx.fields, found.fields);

      let result = db._query(q).toArray();
      assertEqual(result[0], vertices.B);
    }

  };
}

function exampleGraphsSuite() {
  let ex = require('@arangodb/graph-examples/example-graph');

  return {
    setUpAll: () => {
      ex.dropGraph('traversalGraph');
      ex.loadGraph('traversalGraph');
    },

    tearDownAll: () => {
      ex.dropGraph('traversalGraph');
    },

    testMinDepthFilterNEQ: () => {
      let q = `FOR v,e,p IN 1..3 OUTBOUND "circles/A" GRAPH "traversalGraph"
      FILTER p.vertices[1]._key != "G"
      FILTER p.edges[1].label != "left_blub"
      RETURN v._key`;
      let res = db._query(q);
      assertEqual(res.count(), 3);
      let resArr = res.toArray().sort();
      assertEqual(resArr, ['B', 'C', 'D'].sort());

      q = `FOR v,e,p IN 1..3 OUTBOUND "circles/A" GRAPH "traversalGraph"
      FILTER p.vertices[1]._key != "G"
      FILTER "left_blub" != p.edges[1].label
      RETURN v._key`;
      res = db._query(q);
      assertEqual(res.count(), 3);
      resArr = res.toArray().sort();
      assertEqual(resArr, ['B', 'C', 'D'].sort());
    },

    testMinDepthFilterEq: () => {
      let q = `FOR v,e,p IN 1..3 OUTBOUND "circles/A" GRAPH "traversalGraph"
      FILTER p.vertices[1]._key != "G"
      FILTER p.edges[1].label == null
      RETURN v._key`;
      let res = db._query(q);
      assertEqual(res.count(), 1);
      let resArr = res.toArray().sort();
      assertEqual(resArr, ['B'].sort());

      q = `FOR v,e,p IN 1..3 OUTBOUND "circles/A" GRAPH "traversalGraph"
      FILTER p.vertices[1]._key != "G"
      FILTER null == p.edges[1].label
      RETURN v._key`;
      res = db._query(q);
      assertEqual(res.count(), 1);
      resArr = res.toArray().sort();
      assertEqual(resArr, ['B'].sort());
    },

    testMinDepthFilterIn: () => {
      let q = `FOR v,e,p IN 1..3 OUTBOUND "circles/A" GRAPH "traversalGraph"
      FILTER p.vertices[1]._key != "G"
      FILTER p.edges[1].label IN [null, "left_blarg", "foo", "bar", "foxx"]
      RETURN v._key`;
      let res = db._query(q);
      assertEqual(res.count(), 3);
      let resArr = res.toArray().sort();
      assertEqual(resArr, ['B', 'C', 'D'].sort());
    },

    testMinDepthFilterLess: () => {
      let q = `FOR v,e,p IN 1..3 OUTBOUND "circles/A" GRAPH "traversalGraph"
      FILTER p.vertices[1]._key != "G"
      FILTER p.edges[1].label < "left_blub"
      RETURN v._key`;
      let res = db._query(q);
      assertEqual(res.count(), 3);
      let resArr = res.toArray().sort();
      assertEqual(resArr, ['B', 'C', 'D'].sort());

      q = `FOR v,e,p IN 1..3 OUTBOUND "circles/A" GRAPH "traversalGraph"
      FILTER p.vertices[1]._key != "G"
      FILTER "left_blub" > p.edges[1].label
      RETURN v._key`;
      res = db._query(q);
      assertEqual(res.count(), 3);
      resArr = res.toArray().sort();
      assertEqual(resArr, ['B', 'C', 'D'].sort());
    },

    testMinDepthFilterNIN: () => {
      let q = `FOR v,e,p IN 1..3 OUTBOUND "circles/A" GRAPH "traversalGraph"
      FILTER p.vertices[1]._key != "G"
      FILTER p.edges[1].label NOT IN ["left_blub", "foo", "bar", "foxx"]
      RETURN v._key`;
      let res = db._query(q);
      assertEqual(res.count(), 3);
      let resArr = res.toArray().sort();
      assertEqual(resArr, ['B', 'C', 'D'].sort());
    },

    testMinDepthFilterComplexNode: () => {
      let q = `LET condition = { value: "left_blub" }
      FOR v,e,p IN 1..3 OUTBOUND "circles/A" GRAPH "traversalGraph"
      FILTER p.vertices[1]._key != "G"
      FILTER p.edges[1].label != condition.value
      RETURN v._key`;
      let res = db._query(q);
      assertEqual(res.count(), 3);
      let resArr = res.toArray().sort();
      assertEqual(resArr, ['B', 'C', 'D'].sort());

      q = `LET condition = { value: "left_blub" }
      FOR v,e,p IN 1..3 OUTBOUND "circles/A" GRAPH "traversalGraph"
      FILTER p.vertices[1]._key != "G"
      FILTER condition.value != p.edges[1].label
      RETURN v._key`;
      res = db._query(q);
      assertEqual(res.count(), 3);
      resArr = res.toArray().sort();
      assertEqual(resArr, ['B', 'C', 'D'].sort());
    },

    testMinDepthFilterReference: () => {
      let q = `FOR snippet IN ["right"]
      LET test = CONCAT(snippet, "_blob")
      FOR v, e, p IN 1..2 OUTBOUND "circles/A" GRAPH "traversalGraph"
      FILTER p.edges[1].label != test
      RETURN v._key`;

      let res = db._query(q);
      assertEqual(res.count(), 5);
      let resArr = res.toArray().sort();
      assertEqual(resArr, ['B', 'C', 'E', 'G', 'J'].sort());
    }
  };
}

function pruneTraversalSuite() {
  const optionsToTest = {
    DFS: { bfs: false },
    BFS: { bfs: true },
    Neighbors: { bfs: true, uniqueVertices: 'global' }
  };

  // We have identical tests for all traversal options.
  const appendTests = (testObj, name, opts) => {

    testObj[`testAllowPruningOnV${name}`] = () => {
      const q = `
        WITH ${vn}
        FOR v IN 1..3 ANY "${vertex.B}" ${en}
          PRUNE v._key == "C"
          OPTIONS ${JSON.stringify(opts)}
          RETURN v._key
      `;
      const res = db._query(q);

      if (name === "Neighbors") {
        assertEqual(res.count(), 4, `In query ${q}`);
        assertEqual(res.toArray().sort(), ['A', 'C', 'E', 'F'].sort(), `In query ${q}`);
      } else {
        assertEqual(res.count(), 5, `In query ${q}`);
        assertEqual(res.toArray().sort(), ['A', 'C', 'C', 'E', 'F'].sort(), `In query ${q}`);
      }
    };

    testObj[`testAllowPruningOnE${name}`] = () => {
      const q = `
        WITH ${vn}
        FOR v, e IN 1..3 ANY "${vertex.B}" ${en}
          PRUNE e._to == "${vertex.C}"
          OPTIONS ${JSON.stringify(opts)}
          RETURN v._key
      `;
      const res = db._query(q);
      if (name === "Neighbors") {
        assertEqual(res.count(), 4, `In query ${q}`);
        assertEqual(res.toArray().sort(), ['A', 'C', 'E', 'F'].sort(), `In query ${q}`);
      } else {
        assertEqual(res.count(), 5, `In query ${q}`);
        assertEqual(res.toArray().sort(), ['A', 'C', 'C', 'E', 'F'].sort(), `In query ${q}`);
      }
    };

    testObj[`testAllowPruningOnP${name}`] = () => {
      const q = `
                WITH ${vn}
                FOR v, e, p IN 1..3 ANY "${vertex.B}" ${en}
                  PRUNE p.vertices[1]._key == "C"
                  OPTIONS ${JSON.stringify(opts)}
                  RETURN v._key
              `;
      const res = db._query(q);
      if (name === "Neighbors") {
        assertEqual(res.count(), 4, `In query ${q}`);
        assertEqual(res.toArray().sort(), ['A', 'C', 'E', 'F'].sort(), `In query ${q}`);
      } else {
        assertEqual(res.count(), 5, `In query ${q}`);
        assertEqual(res.toArray().sort(), ['A', 'C', 'C', 'E', 'F'].sort(), `In query ${q}`);
      }
    };

    testObj[`testAllowPruningOnPReturnE${name}`] = () => {
      const q = `
                WITH ${vn}
                FOR v, e, p IN 1..3 ANY "${vertex.B}" ${en}
                  PRUNE p.vertices[1]._key == "C"
                  OPTIONS ${JSON.stringify(opts)}
                  RETURN e._id
              `;
      const res = db._query(q);
      if (name === "Neighbors") {
        assertEqual(res.count(), 4, `In query ${q}`);
        assertEqual(res.toArray().sort(), [edge.AB, edge.BC, edge.EB, edge.FE].sort(), `In query ${q}`);
      } else {
        assertEqual(res.count(), 5, `In query ${q}`);
        assertEqual(res.toArray().sort(), [edge.AB, edge.BC, edge.EB, edge.FE, edge.CF].sort(), `In query ${q}`);
      }
    };

    testObj[`testAllowPruningOnOuterVar${name}`] = () => {
      const q = `
                WITH ${vn} 
                FOR key IN ["C", "F"]
                FOR v IN 1..3 ANY "${vertex.B}" ${en}
                  PRUNE v._key == key
                  OPTIONS ${JSON.stringify(opts)}
                  RETURN v._key
              `;
      const res = db._query(q);

      if (name === "Neighbors") {
        const resKeyC = ['A', 'C', 'E', 'F'];
        const resKeyF = ['A', 'C', 'D', 'F', 'E'];
        assertEqual(res.count(), resKeyC.length + resKeyF.length, `In query ${q}`);
        assertEqual(res.toArray().sort(), resKeyC.concat(resKeyF).sort(), `In query ${q}`);
      } else {
        const resKeyC = ['A', 'C', 'C', 'E', 'F'];
        const resKeyF = ['A', 'C', 'D', 'F', 'E', 'F'];
        assertEqual(res.count(), resKeyC.length + resKeyF.length, `In query ${q}`);
        assertEqual(res.toArray().sort(), resKeyC.concat(resKeyF).sort(), `In query ${q}`);
      }
    };

    testObj[`testAllowPruningOnVBelowMinDepth${name}`] = () => {
      const q = `
        WITH ${vn}
        FOR v IN 3 ANY "${vertex.B}" ${en}
          PRUNE v._key == "C"
          OPTIONS ${JSON.stringify(opts)}
          RETURN v._key
      `;
      const res = db._query(q);

      if (name === "Neighbors") {
        assertEqual(res.count(), 0, `In query ${q}`);
        assertEqual(res.toArray().sort(), [].sort(), `In query ${q}`);
      } else {
        assertEqual(res.count(), 1, `In query ${q}`);
        assertEqual(res.toArray().sort(), ['C'].sort(), `In query ${q}`);
      }
    };

    testObj[`testMultipleCoordinatorParts${name}`] = () => {
      // This is intendent to test Cluster to/from VPack function of traverser Nodes
      // On SingleServer this tests pruning on the startVertex
      const q = `
        WITH ${vn}
        FOR v IN 1 ANY "${vertex.B}" ${en}
          PRUNE v._key == "C" /* this actually does not prune */
          OPTIONS ${JSON.stringify(opts)}
          FOR source IN ${vn}
            FILTER source._key == v._key
            FOR k IN 2 ANY source ${en}
            PRUNE k._key == "C"
            OPTIONS ${JSON.stringify(opts)}
            RETURN k._key
      `;

      // The first traversal will find A, C, E
      // The Primary Index Scan in the middle is actually
      // a noop and only enforces a walk thorugh DBServer
      // The Second traversal will find:
      // A => C,E
      // C => [] // it shall prune the startvertex
      // E => A,C,C 
      const res = db._query(q);

      if (name === "Neighbors") {
        // The E part does not find C twice
        assertEqual(res.count(), 4, `In query ${q}`);
        assertEqual(res.toArray().sort(), ["C", "E", "A", "C"].sort(), `In query ${q}`);
      } else {
        assertEqual(res.count(), 5, `In query ${q}`);
        assertEqual(res.toArray().sort(), ["C", "E", "A", "C", "C"].sort(), `In query ${q}`);
      }
    };

  };

  const testObj = {
    setUpAll: () => {
      cleanup();
      createBaseGraph();
    },

    tearDownAll: () => {
      cleanup();
    }
  };

  for (let [name, opts] of Object.entries(optionsToTest)) {
    appendTests(testObj, name, opts);
  }

  return testObj;
}

jsunity.run(invalidStartVertexSuite);
jsunity.run(simpleInboundOutboundSuite);
jsunity.run(limitSuite);
jsunity.run(nestedSuite);
jsunity.run(namedGraphSuite);
jsunity.run(multiCollectionGraphSuite);
jsunity.run(multiEdgeCollectionGraphSuite);
jsunity.run(potentialErrorsSuite);
jsunity.run(complexInternaSuite);
jsunity.run(optimizeInSuite);
jsunity.run(complexFilteringSuite);
jsunity.run(brokenGraphSuite);
jsunity.run(multiEdgeDirectionSuite);
jsunity.run(subQuerySuite);
jsunity.run(optionsSuite);
jsunity.run(optimizeQuantifierSuite);
jsunity.run(exampleGraphsSuite);
if (!isCluster) {
  jsunity.run(optimizeNonVertexCentricIndexesSuite);
}
jsunity.run(pruneTraversalSuite);

return jsunity.done();