Use config.update w/ a key path everywhere we update the config

spec/app/config-spec.coffee

@@ -1,5 +1,13 @@
 describe "Config", ->
-  describe "#observe(keyPath)", ->
+  describe ".update(keyPath, value)", ->
+    it "sets the value at the given key path and emits an update event", ->
+      updateHandler = jasmine.createSpy 'updateHandler'
+      config.on 'update', updateHandler
+      config.update("foo.bar.baz", "hello")
+      expect(config.foo.bar.baz).toBe "hello"
+      expect(updateHandler).toHaveBeenCalled()
+
+  describe ".observe(keyPath)", ->
     observeHandler = null
 
     beforeEach ->
@@ -12,23 +20,19 @@ describe "Config", ->
 
     it "fires the callback every time the observed value changes", ->
       observeHandler.reset() # clear the initial call
-      config.foo.bar.baz = "value 2"
-      config.update()
+      config.update('foo.bar.baz', "value 2")
       expect(observeHandler).toHaveBeenCalledWith("value 2")
       observeHandler.reset()
 
-      config.foo.bar.baz = "value 1"
-      config.update()
+      config.update('foo.bar.baz', "value 1")
       expect(observeHandler).toHaveBeenCalledWith("value 1")
 
     it "fires the callback when the full key path goes into and out of existence", ->
       observeHandler.reset() # clear the initial call
-      delete config.foo.bar
-      config.update()
+      config.update("foo.bar", undefined)
 
       expect(observeHandler).toHaveBeenCalledWith(undefined)
       observeHandler.reset()
 
-      config.foo.bar = { baz: "i'm back" }
-      config.update()
+      config.update("foo.bar.baz", "i'm back")
       expect(observeHandler).toHaveBeenCalledWith("i'm back")

spec/app/editor-spec.coffee

@@ -504,8 +504,7 @@ describe "Editor", ->
 
   describe "font size", ->
     it "sets the initial font size based on the value from config", ->
-      config.editor.fontSize = 20
-      config.update()
+      config.update("editor.fontSize", 20)
       newEditor = editor.splitRight()
       expect(editor.css('font-size')).toBe '20px'
       expect(newEditor.css('font-size')).toBe '20px'
@@ -516,14 +515,12 @@ describe "Editor", ->
         rootView.height(200)
         rootView.width(200)
 
-        config.editor.fontSize = 10
-        config.update()
+        config.update("editor.fontSize", fontSize)
         lineHeightBefore = editor.lineHeight
         charWidthBefore = editor.charWidth
         editor.setCursorScreenPosition [5, 6]
 
-        config.editor.fontSize = 30
-        config.update()
+        config.update("editor.fontSize", 30)
         expect(editor.css('font-size')).toBe '30px'
         expect(editor.lineHeight).toBeGreaterThan lineHeightBefore
         expect(editor.charWidth).toBeGreaterThan charWidthBefore
@@ -533,12 +530,10 @@ describe "Editor", ->
 
       it "updates the position and size of selection regions", ->
         rootView.attachToDom()
-        config.editor.fontSize = 10
-        config.update()
+        config.update("editor.fontSize", 10)
         editor.setSelectedBufferRange([[5, 2], [5, 7]])
 
-        config.editor.fontSize = 30
-        config.update()
+        config.update("editor.fontSize", 30)
         selectionRegion = editor.find('.region')
         expect(selectionRegion.position().top).toBe 5 * editor.lineHeight
         expect(selectionRegion.position().left).toBe 2 * editor.charWidth
@@ -547,8 +542,7 @@ describe "Editor", ->
 
       it "updates the gutter width and font size", ->
         rootView.attachToDom()
-        config.editor.fontSize = 16 * 4
-        config.update()
+        config.update("editor.fontSize", 16 * 4)
         expect(editor.gutter.css('font-size')).toBe "#{16 * 4}px"
         expect(editor.gutter.width()).toBe(141)
 
@@ -557,8 +551,7 @@ describe "Editor", ->
         originalLineCount = editor.renderedLines.find(".line").length
         expect(originalLineCount).toBeGreaterThan 0
 
-        config.editor.fontSize = 10
-        config.update()
+        config.update("editor.fontSize", 10)
         expect(editor.renderedLines.find(".line").length).toBeGreaterThan originalLineCount
 
   describe "mouse events", ->
@@ -1562,11 +1555,10 @@ describe "Editor", ->
         expect(config.editor.showInvisibles).toBeFalsy()
         expect(editor.renderedLines.find('.line').text()).toBe " a line with tabs  and spaces "
 
-        config.editor.showInvisibles = true
-        config.update()
+        config.update("editor.showInvisibles", true)
         expect(editor.renderedLines.find('.line').text()).toBe "•a line with tabs▸ and spaces•¬"
 
-        config.editor.showInvisibles = false
+        config.update("editor.showInvisibles", false)
         config.update()
         expect(editor.renderedLines.find('.line').text()).toBe " a line with tabs  and spaces "
 

spec/app/root-view-spec.coffee

@@ -557,8 +557,7 @@ describe "RootView", ->
       expect(editor.getFontSize()).toBe fontSizeBefore
 
     it "does not allow the font size to be less than 1", ->
-      config.editor.fontSize = 1
-      config.update()
+      config.update("editor.fontSize", 1)
       rootView.trigger 'window:decrease-font-size'
       expect(editor.getFontSize()).toBe 1
 

spec/stdlib/space-pen-extensions-spec.coffee

@@ -24,24 +24,21 @@ describe "SpacePen extensions", ->
       expect(observeHandler).toHaveBeenCalledWith(undefined)
       observeHandler.reset()
 
-      config.foo = { bar: "hello" }
-      config.update()
+      config.update("foo.bar", "hello")
 
       expect(observeHandler).toHaveBeenCalledWith("hello")
       observeHandler.reset()
 
       view.unsubscribe()
 
-      config.foo.bar = "goodbye"
-      config.update()
+      config.update("foo.bar", "goodbye")
 
       expect(observeHandler).not.toHaveBeenCalled()
 
     it "unsubscribes when the view is removed", ->
       observeHandler.reset()
       parent.remove()
-      config.foo = { bar: "hello" }
-      config.update()
+      config.update("foo.bar", "hello")
       expect(observeHandler).not.toHaveBeenCalled()
 
   describe "View#subscribe(eventEmitter, eventName, callback)", ->

src/app/config.coffee

@@ -21,7 +21,8 @@ class Config
     @editor ?= {}
     _.defaults(@editor, require('editor').configDefaults)
 
-  update: ->
+  update: (keyPathString, value) ->
+    @setValueAtKeyPath(keyPathString.split('.'), value) if keyPathString
     @save()
     @trigger 'update'
 
@@ -47,6 +48,15 @@ class Config
       break unless value = value[key]
     value
 
+  setValueAtKeyPath: (keyPath, value) ->
+    keyPath = new Array(keyPath...)
+    hash = this
+    while keyPath.length > 1
+      key = keyPath.shift()
+      hash[key] ?= {}
+      hash = hash[key]
+    hash[keyPath.shift()] = value
+
   observe: (keyPathString, callback) ->
     keyPath = keyPathString.split('.')
     value = @valueAtKeyPath(keyPath)

src/app/root-view.coffee

@@ -88,11 +88,9 @@ class RootView extends View
     @command 'window:focus-next-pane', => @focusNextPane()
     @command 'window:save-all', => @saveAll()
     @command 'window:toggle-invisibles', =>
-      config.editor.showInvisibles = not config.editor.showInvisibles
-      config.update()
+      config.update("editor.showInvisibles", not config.editor.showInvisibles)
     @command 'window:toggle-ignored-files', =>
-      config.core.hideGitIgnoredFiles = not config.core.hideGitIgnoredFiles
-      config.update()
+      config.update("core.hideGitIgnoredFiles", not config.core.hideGitIgnoredFiles)
 
   afterAttach: (onDom) ->
     @focus() if onDom

src/extensions/tree-view/spec/tree-view-spec.coffee

@@ -865,12 +865,10 @@ describe "TreeView", ->
     it "hides git-ignored files if the option is set, but otherwise shows them", ->
       expect(treeView.find('.file:contains(tree-view.js)').length).toBe 1
 
-      config.core.hideGitIgnoredFiles = true
-      config.update()
+      config.update("core.hideGitIgnoredFiles", true)
 
       expect(treeView.find('.file:contains(tree-view.js)').length).toBe 0
 
-      config.core.hideGitIgnoredFiles = false
-      config.update()
+      config.update("core.hideGitIgnoredFiles", false)
 
       expect(treeView.find('.file:contains(tree-view.js)').length).toBe 1