add performance test for loading models with many children that are already in session

test/mocha.opts

@@ -1,3 +1,4 @@
 --compilers em:ember-script/register
 --reporter list
---recursive
+--recursive
+--timeout 3000

test/rest/rest.performace.em

@@ -0,0 +1,56 @@
+describe "rest", ->
+
+  adapter = null
+  session = null
+
+  beforeEach ->
+    require('./_shared').setupRest.apply(this)
+    adapter = @adapter
+    session = @session
+    Ep.__container__ = @container
+
+  afterEach ->
+    delete Ep.__container__
+
+  context 'many children', ->
+
+    beforeEach ->
+
+      class @Post extends Ep.Model
+        title: Ep.attr 'string'
+        comments: Ep.hasMany 'comment'
+
+      @App.Post = @Post
+
+      class @Comment extends Ep.Model
+        message: Ep.attr 'string'
+        post: Ep.belongsTo 'post'
+
+      @App.Comment = @Comment
+
+      @container.register 'model:post', @Post
+      @container.register 'model:comment', @Comment
+
+    it 'loads model with many children to empty session fast', ->
+      # Tell mocha to highlight testcase if it take longer than this threshold
+      # As alternative it is possible to set `@timeout 500` to fail the test
+      @slow 500
+
+      adapter.r['GET:/posts'] = posts: [{id: 1, title: 'is it fast?', rev: 1, comments: [1..100]}],
+      comments: ({id: i, message: "message#{i}", post: 1, rev: 1} for i in [1..100])
+
+      session.query('post').then (posts) ->
+        expect(posts[0].comments.length).to.eq(100)
+
+
+    it 'loads model with many children repeatedly fast when rev is set', ->
+      # Tell mocha to highlight testcase if it take longer than this threshold
+      # As alternative it is possible to set `@timeout 2500` to fail the test
+      @slow 2500
+
+      adapter.r['GET:/posts'] = posts: [{id: 1, title: 'still fast?', rev: 1, comments: [1..100]}],
+      comments: ({id: i, message: "message#{i}", post: 1, rev: 1} for i in [1..100])
+
+      session.query('post').then (posts) ->
+        session.query('post').then (posts) ->
+          expect(posts[0].comments.length).to.eq(100)