Break AtomTheme out into its own file.

spec/app/theme-spec.coffee

@@ -2,7 +2,16 @@ $ = require 'jquery'
 fs = require 'fs'
 Theme = require 'theme'
 
-describe "Theme", ->
+describe "TextMateTheme", ->
+  describe "@load(name)", ->
+    it "applies the theme's stylesheet to the current window", ->
+      themePath = require.resolve(fs.join('fixtures', 'test.tmTheme'))
+      spyOn window, 'applyStylesheet'
+      theme = Theme.load(themePath)
+      expect(window.applyStylesheet).toHaveBeenCalledWith(themePath, theme.getStylesheet())
+      theme.deactivate()
+
+describe "AtomTheme", ->
   describe "@load(name)", ->
     it "Loads and applies css from package.json in the correct order", ->
       themePath = require.resolve(fs.join('fixtures', 'test-atom-theme'))
@@ -14,4 +23,5 @@ describe "Theme", ->
       expect($(document.body).css("padding-top")).toBe("101px")
       expect($(document.body).css("padding-right")).toBe("102px")
       expect($(document.body).css("padding-bottom")).toBe("103px")
+
       theme.deactivate()

src/app/atom-theme.coffee

@@ -0,0 +1,11 @@
+fs = require 'fs'
+Theme = require 'theme'
+
+module.exports =
+class AtomTheme extends Theme
+  constructor: (@path) ->
+    super
+    json = fs.read(fs.join(path, "package.json"))
+    for stylesheetName in JSON.parse(json).stylesheets
+      stylesheetPath = fs.join(@path, stylesheetName)
+      @stylesheets[stylesheetPath] = fs.read(stylesheetPath)

src/app/text-mate-theme.coffee

@@ -5,12 +5,11 @@ Theme = require 'Theme'
 module.exports =
 class TextMateTheme extends Theme
   constructor: (@path, {settings}) ->
+    super
     @rulesets = []
     globalSettings = settings[0]
     @buildGlobalSettingsRulesets(settings[0])
     @buildScopeSelectorRulesets(settings[1..])
-
-    @stylesheets = {}
     @stylesheets[@path] = @getStylesheet()
 
   getStylesheet: ->

src/app/theme.coffee

@@ -4,6 +4,8 @@ _ = require 'underscore'
 
 module.exports =
 class Theme
+  @stylesheets: null
+
   @load: (name) ->
     if fs.exists(name)
       path = name
@@ -11,18 +13,13 @@ class Theme
       regex = new RegExp("#{_.escapeRegExp(name)}(\.[^.]*)?$", "i")
       path = _.find fs.list(config.themeDirPath), (path) -> regex.test(path)
 
-    return null unless path
-
     if @isTextMateTheme(path)
       theme = @loadTextMateTheme(path)
     else
       theme = @loadAtomTheme(path)
 
-    if theme
-      theme.activate()
-    else
-      throw new Error("Cannot activate theme named '#{name}'")
-
+    throw new Error("Cannot activate theme named '#{name}' located at '#{path}'") unless theme
+    theme.activate()
     theme
 
   @loadTextMateTheme: (path) ->
@@ -35,19 +32,14 @@ class Theme
     theme
 
   @loadAtomTheme: (path) ->
-    new Theme(path)
+    AtomTheme = require('atom-theme')
+    new AtomTheme(path)
 
   @isTextMateTheme: (path) ->
     /\.(tmTheme|plist)$/.test(path)
 
-  @stylesheets: null
-
   constructor: (@path) ->
-    json = fs.read(fs.join(path, "package.json"))
     @stylesheets = {}
-    for stylesheetName in JSON.parse(json).stylesheets
-      stylesheetPath = fs.join(@path, stylesheetName)
-      @stylesheets[stylesheetPath] = fs.read(stylesheetPath)
 
   activate: ->
     for stylesheetPath, stylesheetContent of @stylesheets