Only auto-load .cson and .json keymap files

This now prevents files such as .DS_Store from being loaded as a
keymap where previously all paths were loaded regardless of extension.

Closes #205

spec/app/atom-spec.coffee

@@ -26,17 +26,20 @@ describe "the `atom` global", ->
 
     describe "keymap loading", ->
       describe "when package.json does not contain a 'keymaps' manifest", ->
-        it "loads all keymaps in the directory", ->
+        it "loads all the .cson/.json files in the keymaps directory", ->
           element1 = $$ -> @div class: 'test-1'
           element2 = $$ -> @div class: 'test-2'
+          element3 = $$ -> @div class: 'test-3'
 
           expect(keymap.bindingsForElement(element1)['ctrl-z']).toBeUndefined()
           expect(keymap.bindingsForElement(element2)['ctrl-z']).toBeUndefined()
+          expect(keymap.bindingsForElement(element3)['ctrl-z']).toBeUndefined()
 
           atom.loadPackage("package-with-module")
 
           expect(keymap.bindingsForElement(element1)['ctrl-z']).toBe "test-1"
           expect(keymap.bindingsForElement(element2)['ctrl-z']).toBe "test-2"
+          expect(keymap.bindingsForElement(element3)['ctrl-z']).toBeUndefined()
 
       describe "when package.json contains a 'keymaps' manifest", ->
         it "loads only the keymaps specified by the manifest, in the specified order", ->

spec/fixtures/packages/package-with-module/keymaps/keymap-3.cjson

@@ -0,0 +1,2 @@
+".test-3":
+  "ctrl-z": "test-3"

spec/stdlib/fs-spec.coffee

@@ -128,3 +128,8 @@ describe "fs", ->
   describe ".md5ForPath(path)", ->
     it "returns the MD5 hash of the file at the given path", ->
       expect(fs.md5ForPath(require.resolve('fixtures/sample.js'))).toBe 'dd38087d0d7e3e4802a6d3f9b9745f2b'
+
+  describe ".list(path, extensions)", ->
+    it "returns the paths with the specified extensions", ->
+      path = require.resolve('fixtures/css.css')
+      expect(fs.list(require.resolve('fixtures'), ['.css'])).toEqual [path]

src/app/atom-package.coffee

@@ -26,15 +26,12 @@ class AtomPackage extends Package
       @metadata = fs.readObject(metadataPath)
 
   loadKeymaps: ->
-    for keymapPath in @getKeymapPaths()
-      keymap.load(keymapPath)
-
-  getKeymapPaths: ->
     if keymaps = @metadata?.keymaps
-      keymaps.map (relativePath) =>
+      keymaps = keymaps.map (relativePath) =>
         fs.resolve(@keymapsDirPath, relativePath, ['cson', 'json', ''])
+      keymap.load(keymapPath) for keymapPath in keymaps
     else
-      fs.list(@keymapsDirPath)
+      keymap.loadDirectory(@keymapsDirPath)
 
   loadStylesheets: ->
     for stylesheetPath in @getStylesheetPaths()

src/app/keymap.coffee

@@ -35,7 +35,7 @@ class Keymap
     @loadDirectory(fs.join(config.configDirPath, 'keymaps'))
 
   loadDirectory: (directoryPath) ->
-    @load(filePath) for filePath in fs.list(directoryPath)
+    @load(filePath) for filePath in fs.list(directoryPath, ['.cson', '.json'])
 
   load: (path) ->
     @add(fs.readObject(path))

src/stdlib/fs.coffee

@@ -59,11 +59,16 @@ module.exports =
 
   # Returns an array with all the names of files contained
   # in the directory path.
-  list: (rootPath) ->
+  list: (rootPath, extensions) ->
     paths = []
-    onPath = (path) =>
-      paths.push(@join(rootPath, path))
-      false
+    if extensions
+      onPath = (path) =>
+        paths.push(@join(rootPath, path)) if _.contains(extensions, @extension(path))
+        false
+    else
+      onPath = (path) =>
+        paths.push(@join(rootPath, path))
+        false
     @traverseTree(rootPath, onPath, onPath)
     paths