diff --git a/flowtype.md b/flowtype.md
index 1d4df6444..756396bfc 100644
--- a/flowtype.md
+++ b/flowtype.md
@@ -119,6 +119,7 @@ function filter<T> (list: Array<T>, callback: (item: T) => boolean): Array<T> {
 
 ```js
 import type { Person } from '../person'
+import typeof Config from '../config'
 ```
 
 ```js
@@ -142,3 +143,26 @@ var add: ((num1: number, num2: number) => number) = function(num1, num2) {
   return num1 + num2;
 };
 ```
+
+## Comment syntax
+
+```js
+/*::
+  export type Foo = { ... }
+*/
+
+function add(n /*: number */) { ... }
+```
+
+## React
+
+```js
+React$Element<any>
+```
+
+```js
+class Foo extends React.Component {
+  /*:: state: { open: boolean } */
+  /*:: props: { open: boolean } */
+}
+```
diff --git a/nodejs-stream.md b/nodejs-stream.md
new file mode 100644
index 000000000..f23cb4903
--- /dev/null
+++ b/nodejs-stream.md
@@ -0,0 +1,83 @@
+---
+title: Stream
+category: Node.js
+---
+
+```js
+const Readable = require('stream').Readable
+const Writable = require('stream').Writable
+const Transform = require('stream').Transform
+```
+
+### Piping
+
+```js
+clock()                 // Readable stream
+  .pipe(xformer())      // Transform stream
+  .pipe(renderer())     // Writable stream
+```
+
+### Readable streams
+
+Readable streams are generators of data. Write data using `stream.push()`.
+
+```js
+function clock () {
+  const stream = new Readable({
+    objectMode: true,
+    read: () => {} // implement this if you need on-demand reading
+  })
+
+  setInterval(() => {
+    stream.push({ time: new Date() })
+
+    if (error) return stream.emit('error', error)
+    if (eof) return stream.push(null)
+  }, 1000)
+
+  return stream
+}
+```
+
+### Transform streams
+
+Pass the updated chunk to `done(null, chunk)`.
+
+```js
+function xformer () {
+  let count = 0
+
+  return new Transform({
+    objectMode: true,
+    transform: (data, _, done) => {
+      done(null, { time: data.time, index: count++ })
+    }
+  })
+}
+```
+
+### Writable streams
+
+```js
+function renderer () {
+  return new Writable({
+    objectMode: true,
+    write: (data, _, done) => {
+      console.log('<-', data)
+      done()
+    }
+  })
+}
+```
+
+### Reading
+
+```js
+const st = source()
+st.on('data', (data) => { console.log('<-', data) })
+st.on('close', () => { console.log('** bye') })
+```
+
+## Also see
+
+- <https://github.com/substack/stream-handbook>
diff --git a/rails-models.md b/rails-models.md
index c1aa09e55..3ac3e5458 100644
--- a/rails-models.md
+++ b/rails-models.md
@@ -348,9 +348,18 @@ Other API
 
 ### Joining
 
-    Student.joins(:schools).where(:schools => { :type => 'public' })
+    Student.joins(:schools).where(schools: { type: 'public' })
     Student.joins(:schools).where('schools.type' => 'public' )
 
+    # multiple associations
+    Article.joins(:category, :comments)
+
+    # nested assocations
+    Article.joins(comments: :guest)
+
+    # sql
+    Author.joins("INNER JOIN posts ON posts.author_id = authors.id AND posts.published = 't'")
+
 ### Where interpolation
 
     where("name = ?", "John")
diff --git a/rspec.md b/rspec.md
index 44afa2391..9c4301f6b 100644
--- a/rspec.md
+++ b/rspec.md
@@ -148,6 +148,7 @@ book = instance_double('Book', pages: 250)
 ```rb
 allow(die).to receive(:roll)
 allow(die).to receive(:roll) { 3 }
+allow_any_instance_of(Die).to receive(:roll)
 
 expect(die).to receive(:roll)
   .with(1)