Add support for decorators

Closes #163

Author: winstliu

grammars/javascript.cson

@@ -258,6 +258,63 @@
       }
     ]
   }
+  {
+    'begin': '^\\s*(?=@\\s*[A-Za-z_][A-Za-z0-9_]*(?:\\.[a-zA-Z_][a-zA-Z_0-9]*)*\\s*\\()'
+    'end': '(\\))'
+    'endCaptures':
+      '1':
+        'name': 'punctuation.definition.arguments.end.js'
+    'name': 'meta.function.decorator.js'
+    'patterns': [
+      {
+        'begin': '(?=(@)\\s*[A-Za-z_][A-Za-z0-9_]*(?:\\.[A-Za-z_][A-Za-z0-9_]*)*\\s*\\()'
+        'beginCaptures':
+          '1':
+            'name': 'punctuation.definition.decorator.js'
+        'contentName': 'entity.name.function.decorator.js'
+        'end': '(?=\\s*\\()'
+      }
+      {
+        'begin': '(\\()'
+        'beginCaptures':
+          '1':
+            'name': 'punctuation.definition.arguments.begin.js'
+        'contentName': 'meta.function.decorator.arguments.js'
+        'end': '(?=\\))'
+        'patterns': [
+          {
+            'include': '#function-params'
+          }
+          {
+            'include': '#comments'
+          }
+          {
+            'include': '$self'
+          }
+        ]
+      }
+    ]
+  }
+  {
+    'begin': '^\\s*(?=@\\s*[A-Za-z_][A-Za-z0-9_]*(?:\\.[a-zA-Z_][a-zA-Z_0-9]*)*)'
+    'contentName': 'entity.name.function.annotation.js'
+    'end': '(?=\\s|$\\n?|//)'
+    'name': 'meta.function.annotation.js'
+    'patterns': [
+      {
+        'begin': '(?=(@)\\s*[A-Za-z_][A-Za-z0-9_]*(\\.[A-Za-z_][A-Za-z0-9_]*)*)'
+        'beginCaptures':
+          '1':
+            'name': 'punctuation.definition.annotation.js'
+        'end': '(?=\\s|$\\n?|//)'
+        'patterns': [
+          {
+            'include': '#comments'
+          }
+        ]
+      }
+    ]
+  }
   {
     'begin': '\\b(constructor)\\s*(\\()'
     'beginCaptures':

spec/javascript-spec.coffee

@@ -478,6 +478,18 @@ describe "Javascript grammar", ->
       expect(tokens[4]).toEqual value: ')', scopes: ['source.js', 'meta.function.arrow.js', 'punctuation.definition.parameters.end.js']
       expect(tokens[5]).toEqual value: '=>', scopes: ['source.js', 'meta.function.arrow.js', 'storage.type.arrow.js']
 
+  describe "decorators and annotations", ->
+    it "tokenizes decorators", ->
+      {tokens} = grammar.tokenizeLine('@thisIsADecorator(true)')
+      expect(tokens[0]).toEqual value: '@thisIsADecorator', scopes: ['source.js', 'meta.function.decorator.js', 'entity.name.function.decorator.js']
+      expect(tokens[1]).toEqual value: '(', scopes: ['source.js', 'meta.function.decorator.js', 'punctuation.definition.arguments.begin.js']
+      expect(tokens[2]).toEqual value: 'true', scopes: ['source.js', 'meta.function.decorator.js', 'meta.function.decorator.arguments.js', 'variable.parameter.function.js']
+      expect(tokens[3]).toEqual value: ')', scopes: ['source.js', 'meta.function.decorator.js', 'punctuation.definition.arguments.end.js']
+
+    it "tokenizes annotations", ->
+      {tokens} = grammar.tokenizeLine('@thisIsAnAnnotation')
+      expect(tokens[0]).toEqual value: '@thisIsAnAnnotation', scopes: ['source.js', 'meta.function.annotation.js', 'entity.name.function.annotation.js']
+
   describe "comments", ->
     it "tokenizes /* */ comments", ->
       {tokens} = grammar.tokenizeLine('/**/')