Project.proto.open emits a 'new-buffer' event if a new buffer is created

RootView.proto.open always uses Project's open method now. RootView creates a project with no path when editing a new buffer, so there's always a project.

spec/app/project-spec.coffee

@@ -6,6 +6,39 @@ describe "Project", ->
   beforeEach ->
     project = new Project(require.resolve('fixtures/dir'))
 
+  describe ".open(path)", ->
+    [absolutePath, newBufferHandler] = []
+    beforeEach ->
+      absolutePath = require.resolve('fixtures/dir/a')
+      newBufferHandler = jasmine.createSpy('newBufferHandler')
+      project.on 'new-buffer', newBufferHandler
+
+    describe "when given an absolute path that hasn't been opened previously", ->
+      it "returns a new buffer for the given path and emits a 'new-buffer' event", ->
+        buffer = project.open(absolutePath)
+        expect(buffer.path).toBe absolutePath
+        expect(newBufferHandler).toHaveBeenCalledWith buffer
+        
+    describe "when given a relative path that hasn't been opened previously", ->
+      it "returns a buffer for the given path (relative to the project root) and emits a 'new-buffer' event", ->
+        buffer = project.open('a')
+        expect(buffer.path).toBe absolutePath
+        expect(newBufferHandler).toHaveBeenCalledWith buffer
+
+    describe "when passed the path to a buffer that has already been opened", ->
+      it "returns the previously opened buffer", ->
+        buffer = project.open(absolutePath)
+        newBufferHandler.reset()        
+        expect(project.open(absolutePath)).toBe buffer        
+        expect(project.open('a')).toBe buffer
+        expect(newBufferHandler).not.toHaveBeenCalled()
+        
+    describe "when not passed a path", ->
+      it "returns a new buffer and emits a new-buffer event", ->
+        buffer = project.open()
+        expect(buffer.path).toBeUndefined()
+        expect(newBufferHandler).toHaveBeenCalledWith(buffer)
+    
   describe ".getFilePaths()", ->
     it "returns a promise which resolves to a list of all file paths in the project, recursively", ->
       expectedPaths = (path.replace(project.path, '') for path in fs.listTree(project.path) when fs.isFile path)
@@ -14,28 +47,9 @@ describe "Project", ->
         project.getFilePaths().done (result) ->
           expect(result).toEqual(expectedPaths)
 
-  describe ".open(path)", ->
-    absolutePath = null
-    beforeEach ->
-      absolutePath = require.resolve('fixtures/dir/a')
-
-    it "always returns the same buffer for the same canonical path", ->
-      buffer = project.open(absolutePath)
-      expect(project.open(absolutePath)).toBe buffer
-      expect(project.open('a')).toBe buffer
-
-    describe "when given an absolute path", ->
-      it "returns a buffer for the given path", ->
-        expect(project.open(absolutePath).path).toBe absolutePath
-
-    describe "when given a relative path", ->
-      it "returns a buffer for the given path (relative to the project root)", ->
-        expect(project.open('a').path).toBe absolutePath
-
   describe ".resolve(path)", ->
     it "returns an absolute path based on the project's root", ->
       absolutePath = require.resolve('fixtures/dir/a')
       expect(project.resolve('a')).toBe absolutePath
       expect(project.resolve(absolutePath + '/../a')).toBe absolutePath
       expect(project.resolve('a/../a')).toBe absolutePath
-

spec/app/root-view-spec.coffee

@@ -396,7 +396,7 @@ describe "RootView", ->
 
     it "creates a project if there isn't one yet and the buffer was previously unsaved", ->
       rootView = new RootView
-      expect(rootView.project).toBeUndefined()
+      expect(rootView.project.path).toBeUndefined()
       rootView.activeEditor().buffer.saveAs('/tmp/ignore-me')
       expect(rootView.project.path).toBe '/tmp/'
 

src/app/project.coffee

@@ -1,8 +1,9 @@
 fs = require 'fs'
 Buffer = require 'buffer'
+_ = require 'underscore'
+EventEmitter = require 'event-emitter'
 
 module.exports =
-
 class Project
   buffers: null
 
@@ -15,10 +16,19 @@ class Project
       path.replace(projectPath, "") for path in paths when fs.isFile(path)
 
   open: (filePath) ->
-    filePath = @resolve filePath
-    @buffers[filePath] ?= new Buffer(filePath)
+    if filePath?
+      filePath = @resolve(filePath)
+      buffer = @buffers[filePath]
+      unless buffer
+        @buffers[filePath] = buffer = new Buffer(filePath)
+        @trigger 'new-buffer', buffer
+    else
+      buffer = new Buffer
+      @trigger 'new-buffer', buffer
+    buffer
 
   resolve: (filePath) ->
     filePath = fs.join(@path, filePath) unless filePath[0] == '/'
     fs.absolute filePath
 
+_.extend Project.prototype, EventEmitter

src/app/root-view.coffee

@@ -42,6 +42,7 @@ class RootView extends View
       @project = new Project(fs.directory(pathToOpen))
       @open(pathToOpen) if fs.isFile(pathToOpen)
     else if not panesViewState?
+      @project = new Project
       @open()
 
     @deserializePanes(panesViewState) if panesViewState
@@ -65,7 +66,7 @@ class RootView extends View
       when 'Editor' then Editor.deserialize(viewState)
 
   open: (path) ->
-    buffer = if path then @project.open(path) else new Buffer
+    buffer = @project.open(path)
 
     if @activeEditor()
       @activeEditor().setBuffer(buffer)
@@ -86,7 +87,7 @@ class RootView extends View
         .on 'buffer-path-change.root-view', =>
           path = editor.buffer.path
           @setTitle(path)
-          @project ?= new Project(fs.directory(path)) if path
+          @project.path ?= fs.directory(path) if path
 
       @setTitle(editor.buffer.path)
 
@@ -108,7 +109,7 @@ class RootView extends View
     rootPane?.adjustDimensions()
 
   toggleFileFinder: ->
-    return unless @project
+    return unless @project.path?
 
     if @fileFinder and @fileFinder.parent()[0]
       @fileFinder.remove()