Merge pull request #3671 from atom/ns-require-stylesheet-disposable

Return a Disposable from ThemeManager::requireStylesheet

spec/theme-manager-spec.coffee

@@ -52,7 +52,7 @@ describe "ThemeManager", ->
 
       expect(themeManager.getEnabledThemeNames()).toEqual ['atom-dark-ui', 'atom-light-ui']
 
-  describe "getImportPaths()", ->
+  describe "::getImportPaths()", ->
     it "returns the theme directories before the themes are loaded", ->
       atom.config.set('core.themes', ['theme-with-index-less', 'atom-dark-ui', 'atom-light-ui'])
 
@@ -129,7 +129,7 @@ describe "ThemeManager", ->
       spyOn(console, 'warn')
       expect(-> atom.packages.activatePackage('a-theme-that-will-not-be-found')).toThrow()
 
-  describe "requireStylesheet(path)", ->
+  describe "::requireStylesheet(path)", ->
     it "synchronously loads css at the given path and installs a style tag for it in the head", ->
       themeManager.onDidChangeStylesheets stylesheetsChangedHandler = jasmine.createSpy("stylesheetsChangedHandler")
       themeManager.onDidAddStylesheet stylesheetAddedHandler = jasmine.createSpy("stylesheetAddedHandler")
@@ -185,18 +185,17 @@ describe "ThemeManager", ->
       $('head style[id*="css.css"]').remove()
       $('head style[id*="sample.less"]').remove()
 
-  describe ".removeStylesheet(path)", ->
-    it "removes styling applied by given stylesheet path", ->
+    it "returns a disposable allowing styles applied by the given path to be removed", ->
       cssPath = require.resolve('./fixtures/css.css')
 
       expect($(document.body).css('font-weight')).not.toBe("bold")
-      themeManager.requireStylesheet(cssPath)
+      disposable = themeManager.requireStylesheet(cssPath)
       expect($(document.body).css('font-weight')).toBe("bold")
 
       themeManager.onDidRemoveStylesheet stylesheetRemovedHandler = jasmine.createSpy("stylesheetRemovedHandler")
       themeManager.onDidChangeStylesheets stylesheetsChangedHandler = jasmine.createSpy("stylesheetsChangedHandler")
 
-      themeManager.removeStylesheet(cssPath)
+      disposable.dispose()
 
       expect($(document.body).css('font-weight')).not.toBe("bold")
 

src/theme-manager.coffee

@@ -2,7 +2,7 @@ path = require 'path'
 
 _ = require 'underscore-plus'
 EmitterMixin = require('emissary').Emitter
-{Emitter} = require 'event-kit'
+{Emitter, Disposable} = require 'event-kit'
 {File} = require 'pathwatcher'
 fs = require 'fs-plus'
 Q = require 'q'
@@ -182,16 +182,16 @@ class ThemeManager
   # * `stylesheetPath` A {String} path to the stylesheet that can be an absolute
   #   path or a relative path that will be resolved against the load path.
   #
-  # Returns the absolute path to the required stylesheet.
+  # Returns a {Disposable} on which `.dispose()` can be called to remove the
+  # required stylesheet.
   requireStylesheet: (stylesheetPath, type='bundled') ->
     if fullPath = @resolveStylesheet(stylesheetPath)
       content = @loadStylesheet(fullPath)
       @applyStylesheet(fullPath, content, type)
+      new Disposable => @removeStylesheet(fullPath)
     else
       throw new Error("Could not find a file at path '#{stylesheetPath}'")
 
-    fullPath
-
   unwatchUserStylesheet: ->
     @userStylesheetFile?.off()
     @userStylesheetFile = null