Create a warning notification when buffer has a watch error

spec/project-spec.coffee

@@ -51,6 +51,25 @@ describe "Project", ->
         editor.saveAs(tempFile)
         expect(atom.project.getPaths()[0]).toBe path.dirname(tempFile)
 
+  describe "when a watch error is thrown from the TextBuffer", ->
+    editor = null
+    beforeEach ->
+      waitsForPromise ->
+        atom.project.open(require.resolve('./fixtures/dir/a')).then (o) -> editor = o
+
+    it "creates a warning notification", ->
+      atom.notifications.onDidAddNotification noteSpy = jasmine.createSpy()
+
+      editor.buffer.emitter.emit 'will-throw-watch-error',
+        handle: jasmine.createSpy()
+        error: new Error('SomeError')
+
+      expect(noteSpy).toHaveBeenCalled()
+
+      notification = noteSpy.mostRecentCall.args[0]
+      expect(notification.getType()).toBe 'warning'
+      expect(notification.getDetail()).toBe 'SomeError'
+
   describe ".open(path)", ->
     [absolutePath, newBufferHandler] = []
 

src/project.coffee

@@ -39,9 +39,7 @@ class Project extends Model
     @emitter = new Emitter
     @buffers ?= []
 
-    for buffer in @buffers
-      do (buffer) =>
-        buffer.onDidDestroy => @removeBuffer(buffer)
+    @subscribeToBuffer(buffer) for buffer in @buffers
 
     Grim.deprecate("Pass 'paths' array instead of 'path' to project constructor") if path?
     paths ?= _.compact([path])
@@ -297,11 +295,11 @@ class Project extends Model
 
   addBuffer: (buffer, options={}) ->
     @addBufferAtIndex(buffer, @buffers.length, options)
-    buffer.onDidDestroy => @removeBuffer(buffer)
+    @subscribeToBuffer(buffer)
 
   addBufferAtIndex: (buffer, index, options={}) ->
     @buffers.splice(index, 0, buffer)
-    buffer.onDidDestroy => @removeBuffer(buffer)
+    @subscribeToBuffer(buffer)
     @emit 'buffer-created', buffer
     buffer
 
@@ -330,6 +328,17 @@ class Project extends Model
     else
       @on 'buffer-created', (buffer) -> callback(buffer)
 
+  subscribeToBuffer: (buffer) ->
+    buffer.onDidDestroy => @removeBuffer(buffer)
+    buffer.onWillThrowWatchError ({error, handle}) =>
+      handle()
+      atom.notifications.addWarning """
+        Unable to read file after file change event.
+        Make sure you have permission to access the file.
+        """,
+        detail: error.message
+        dismissable: true
+
   # Deprecated: delegate
   registerOpener: (opener) ->
     deprecate("Use Workspace::addOpener instead")