Support unsetting explicit grammar for path

spec/app/grammar-view-spec.coffee

@@ -0,0 +1,49 @@
+RootView = require 'root-view'
+GrammarView = require 'grammar-view'
+_ = require 'underscore'
+
+describe "GrammarView", ->
+  [editor, rootView, textGrammar, jsGrammar] =  []
+
+  beforeEach ->
+    path = require.resolve('fixtures/sample.js')
+    syntax.removeGrammarForPath(path)
+    rootView = new RootView(path)
+    editor = rootView.getActiveEditor()
+    rootView.attachToDom()
+    textGrammar = _.find syntax.grammars, (grammar) -> grammar.name is 'Plain Text'
+    expect(textGrammar).toBeTruthy()
+    jsGrammar = _.find syntax.grammars, (grammar) -> grammar.name is 'JavaScript'
+    expect(jsGrammar).toBeTruthy()
+    expect(editor.getGrammar()).toBe jsGrammar
+
+  afterEach ->
+    rootView.deactivate()
+
+  describe "when editor:select-grammar is toggled", ->
+    it "displays a list of all the available grammars", ->
+      editor.trigger 'editor:select-grammar'
+      grammarView = rootView.find('.grammar-view').view()
+      expect(grammarView).toExist()
+      grammars = syntax.grammars
+      expect(grammarView.list.children('li').length).toBe grammars.length + 1
+      expect(grammarView.list.children('li:first').text()).toBe 'Auto Detect'
+
+  describe "when a grammar is selected", ->
+    it "sets the new grammar on the editor", ->
+      editor.trigger 'editor:select-grammar'
+      grammarView = rootView.find('.grammar-view').view()
+      grammarView.confirmed(textGrammar)
+      expect(editor.getGrammar()).toBe textGrammar
+
+  describe "when auto-detect is selected", ->
+    it "restores the auto-detected grammar on the editor", ->
+      editor.trigger 'editor:select-grammar'
+      grammarView = rootView.find('.grammar-view').view()
+      grammarView.confirmed(textGrammar)
+      expect(editor.getGrammar()).toBe textGrammar
+
+      editor.trigger 'editor:select-grammar'
+      grammarView = rootView.find('.grammar-view').view()
+      grammarView.confirmed(grammarView.array[0])
+      expect(editor.getGrammar()).toBe jsGrammar