From 3b1df26a79fd3755b0c77b21b1de9b33b6605844 Mon Sep 17 00:00:00 2001
From: Jan Steemann <jan@arangodb.com>
Date: Fri, 4 Dec 2015 10:53:01 +0100
Subject: [PATCH 1/2] added AQL function `IS_DATESTRING`

---
 CHANGELOG                                     | 11 +++
 .../Books/Users/Aql/DateFunctions.mdpp        |  5 ++
 arangod/Aql/Executor.cpp                      |  1 +
 js/server/modules/org/arangodb/aql.js         | 30 +++++++
 js/server/tests/aql-functions-date.js         | 87 +++++++++++++++++++
 5 files changed, 134 insertions(+)

diff --git a/CHANGELOG b/CHANGELOG
index de35f61f10..aea5ca63f0 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,6 +1,17 @@
 v2.8.0 (XXXX-XX-XX)
 -------------------
 
+* added AQL function `IS_DATESTRING(value)`
+
+  Returns true if *value* is a string that can be used in a date function. 
+  This includes partial dates such as *2015* or *2015-10* and strings containing
+  invalid dates such as *2015-02-31*. The function will return false for all 
+  non-string values, even if some of them may be usable in date functions.
+
+
+v2.8.0-alpha1 (2015-12-03)
+--------------------------
+
 * added AQL keywords `GRAPH`, `OUTBOUND`, `INBOUND` and `ANY` for use in graph 
   traversals, reserved AQL keyword `ALL` for future use
 
diff --git a/Documentation/Books/Users/Aql/DateFunctions.mdpp b/Documentation/Books/Users/Aql/DateFunctions.mdpp
index 6f1933d296..6eb9d799f7 100644
--- a/Documentation/Books/Users/Aql/DateFunctions.mdpp
+++ b/Documentation/Books/Users/Aql/DateFunctions.mdpp
@@ -370,6 +370,11 @@ DATE_FORMAT("2016", "%%l = %l") // "%l = 1" (2016 is a leap year)
 DATE_FORMAT("2016-03-01", "%xxx%") // "063", trailing % ignored
 ```
 
+- *IS_DATESTRING(value)*: Returns true if *value* is a string that can be used
+  in a date function. This includes partial dates such as *2015* or *2015-10* and
+  strings containing invalid dates such as *2015-02-31*. The function will return 
+  false for all non-string values, even if some of them may be usable in date functions.
+
 !SECTION Working with dates and indices
 
 There are two recommended ways to store timestamps in ArangoDB:
diff --git a/arangod/Aql/Executor.cpp b/arangod/Aql/Executor.cpp
index efa61ff7c1..0f4717e21a 100644
--- a/arangod/Aql/Executor.cpp
+++ b/arangod/Aql/Executor.cpp
@@ -111,6 +111,7 @@ std::unordered_map<std::string, Function const> const Executor::FunctionNames{
   { "IS_OBJECT",                   Function("IS_OBJECT",                   "AQL_IS_OBJECT", ".", true, true, false, true, true, &Functions::IsObject) },
   // IS_DOCUMENT is an alias for IS_OBJECT
   { "IS_DOCUMENT",                 Function("IS_DOCUMENT",                 "AQL_IS_DOCUMENT", ".", true, true, false, true, true, &Functions::IsObject) }, 
+  { "IS_DATESTRING",               Function("IS_DATESTRING",               "AQL_IS_DATESTRING", ".", true, true, false, true, true) }, 
   
   // type cast functions
   { "TO_NUMBER",                   Function("TO_NUMBER",                   "AQL_TO_NUMBER", ".", true, true, false, true, true, &Functions::ToNumber) },
diff --git a/js/server/modules/org/arangodb/aql.js b/js/server/modules/org/arangodb/aql.js
index 804ce2b02b..374b3002ac 100644
--- a/js/server/modules/org/arangodb/aql.js
+++ b/js/server/modules/org/arangodb/aql.js
@@ -2703,6 +2703,35 @@ function AQL_IS_OBJECT (value) {
   return (TYPEWEIGHT(value) === TYPEWEIGHT_OBJECT);
 }
 
+////////////////////////////////////////////////////////////////////////////////
+/// @brief test if value is of a valid datestring
+///
+/// returns a bool
+////////////////////////////////////////////////////////////////////////////////
+
+function AQL_IS_DATESTRING (value) {
+  'use strict';
+    
+  if (TYPEWEIGHT(value) !== TYPEWEIGHT_STRING) {
+    return false;
+  }
+
+  // argument is a string
+
+  // append zulu time specifier if no other present
+  if (! value.match(/([zZ]|[+\-]\d+(:\d+)?)$/) ||
+      (value.match(/-\d+(:\d+)?$/) && ! value.match(/[tT ]/))) {
+    value += 'Z';
+  }
+
+  // detect invalid dates ("foo" -> "fooZ" -> getTime() == NaN)
+  var date = new Date(value);
+  if (isNaN(date)) {
+    return false;
+  }
+  return true;
+}
+
 // -----------------------------------------------------------------------------
 // --SECTION--                                                 numeric functions
 // -----------------------------------------------------------------------------
@@ -9158,6 +9187,7 @@ exports.AQL_IS_ARRAY = AQL_IS_ARRAY;
 exports.AQL_IS_LIST = AQL_IS_ARRAY; // alias
 exports.AQL_IS_OBJECT = AQL_IS_OBJECT;
 exports.AQL_IS_DOCUMENT = AQL_IS_OBJECT; // alias
+exports.AQL_IS_DATESTRING = AQL_IS_DATESTRING;
 exports.AQL_FLOOR = AQL_FLOOR;
 exports.AQL_CEIL = AQL_CEIL;
 exports.AQL_ROUND = AQL_ROUND;
diff --git a/js/server/tests/aql-functions-date.js b/js/server/tests/aql-functions-date.js
index d445ed16f5..93963f3974 100644
--- a/js/server/tests/aql-functions-date.js
+++ b/js/server/tests/aql-functions-date.js
@@ -42,6 +42,93 @@ var assertQueryWarningAndNull = helper.assertQueryWarningAndNull;
 function ahuacatlDateFunctionsTestSuite () {
   return {
 
+////////////////////////////////////////////////////////////////////////////////
+/// @brief test is_datestring function
+////////////////////////////////////////////////////////////////////////////////
+
+    testIsDateString : function () {
+      var values = [
+        [ "2000-04-29", true ],
+        [ "2000-04-29Z", true ],
+        [ "2012-02-12 13:24:12", true ],
+        [ "2012-02-12 13:24:12Z", true ],
+        [ "2012-02-12 23:59:59.991", true ],
+        [ "2012-02-12 23:59:59.991Z", true ],
+        [ "2012-02-12", true ],
+        [ "2012-02-12Z", true ],
+        [ "2012-02-12T13:24:12Z", true ],
+        [ "2012-02-12Z", true ],
+        [ "2012-2-12Z", true ],
+        [ "1910-01-02T03:04:05Z", true ],
+        [ "1910-01-02 03:04:05Z", true ],
+        [ "1910-01-02", true ],
+        [ "1910-01-02Z", true ],
+        [ "1970-01-01T01:05:27", true ],
+        [ "1970-01-01T01:05:27Z", true ],
+        [ "1970-01-01 01:05:27Z", true ],
+        [ "1970-1-1Z", true ],
+        [ "1970-1-1", true ],
+        [ "1221-02-28T23:59:59Z", true ],
+        [ "1221-02-28 23:59:59Z", true ],
+        [ "1221-02-28Z", true ],
+        [ "1221-2-28Z", true ],
+        [ "1000-12-24T04:12:00Z", true ],
+        [ "1000-12-24Z", true ],
+        [ "1000-12-24 04:12:00Z", true ],
+        [ "6789-12-31T23:59:58.99Z", true ],
+        [ "6789-12-31Z", true ],
+        [ "9999-12-31T23:59:59.999Z", true ],
+        [ "9999-12-31Z", true ],
+        [ "9999-12-31z", true ],
+        [ "9999-12-31", true ],
+        [ "2012Z", true ],
+        [ "2012z", true ],
+        [ "2012", true ],
+        [ "2012-1Z", true ],
+        [ "2012-1z", true ],
+        [ "2012-1-1z", true ],
+        [ "2012-01-01Z", true ],
+        [ "2012-01-01Z", true ],
+        [ "  2012-01-01Z", true ],
+        [ "  2012-01-01z", true ],
+        [ "foo2012-01-01z", false ],
+        [ "2012-01-01foo", false ],
+        [ "foo", false ],
+        [ "bar", false ],
+        [ "2015-foobar", false ],
+        [ "", false ],
+        [ -95674000, false ],
+        [ 1399395674000, false ],
+        [ 60123, false ],
+        [ 1, false ],
+        [ 0, false ],
+        [ -4, false ],
+        [ true, false ],
+        [ false, false ],
+        [ null, false ],
+        [ [ ], false ],
+        [ [ 1 ], false ],
+        [ [ "foo" ], false ],
+        [ [ "foo", "bar" ], false ],
+        [ [ "2015-01-23" ], false ],
+        [ { }, false ]
+      ];
+
+      values.forEach(function (value) {
+        var actual = getQueryResults("RETURN IS_DATESTRING(@value)", { value: value[0] });
+        assertEqual([ value[1] ], actual, value);
+      });
+    },
+
+////////////////////////////////////////////////////////////////////////////////
+/// @brief test is_datestring function
+////////////////////////////////////////////////////////////////////////////////
+
+    testIsDateStringInvalid : function () {
+      assertQueryError(errors.ERROR_QUERY_FUNCTION_ARGUMENT_NUMBER_MISMATCH.code, "RETURN IS_DATESTRING()");
+      assertQueryError(errors.ERROR_QUERY_FUNCTION_ARGUMENT_NUMBER_MISMATCH.code, "RETURN IS_DATESTRING('foo', 'bar')");
+    },
+
 ////////////////////////////////////////////////////////////////////////////////
 /// @brief test date_now function
 ////////////////////////////////////////////////////////////////////////////////

From f4f90bb5a9c77464c6469740c5ce056cdae1955c Mon Sep 17 00:00:00 2001
From: Jan Steemann <jan@arangodb.com>
Date: Fri, 4 Dec 2015 11:16:02 +0100
Subject: [PATCH 2/2] updated docs

---
 Documentation/Books/Users/Aql/TypeCastFunctions.mdpp | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/Documentation/Books/Users/Aql/TypeCastFunctions.mdpp b/Documentation/Books/Users/Aql/TypeCastFunctions.mdpp
index 28ac3a1ea4..9659b27653 100644
--- a/Documentation/Books/Users/Aql/TypeCastFunctions.mdpp
+++ b/Documentation/Books/Users/Aql/TypeCastFunctions.mdpp
@@ -80,3 +80,8 @@ The following type check functions are available:
 - *IS_OBJECT(value)*: Checks whether *value* is an *object* / *document* value
 
 - *IS_DOCUMENT(value)*: This is an alias for *IS_OBJECT*
+
+- *IS_DATESTRING(value)*: Checks whether *value* is a string that can be used
+  in a date function. This includes partial dates such as *2015* or *2015-10* and
+  strings containing invalid dates such as *2015-02-31*. The function will return 
+  false for all non-string values, even if some of them may be usable in date functions.