Add Project::addPath

spec/project-spec.coffee

@@ -259,6 +259,16 @@ describe "Project", ->
           expect(repo3.getShortHead()).toBe "master"
           expect(repo3.getPath()).toBe fs.realpathSync(path.join(directory3, ".git"))
 
+      it "calls callbacks registered with ::onDidChangePaths", ->
+        onDidChangePathsSpy = jasmine.createSpy('onDidChangePaths spy')
+        atom.project.onDidChangePaths(onDidChangePathsSpy)
+
+        paths = [ temp.mkdirSync("dir1"), temp.mkdirSync("dir2") ]
+        atom.project.setPaths(paths)
+
+        expect(onDidChangePathsSpy.callCount).toBe 1
+        expect(onDidChangePathsSpy.mostRecentCall.args[0]).toEqual(paths)
+
     describe "when path is null", ->
       it "sets its path and root directory to null", ->
         atom.project.setPaths([])
@@ -270,6 +280,19 @@ describe "Project", ->
       expect(atom.project.getPaths()[0]).toEqual path.dirname(require.resolve('./fixtures/dir/a'))
       expect(atom.project.getDirectories()[0].path).toEqual path.dirname(require.resolve('./fixtures/dir/a'))
 
+  describe ".addPath(path)", ->
+    it "calls callbacks registered with ::onDidChangePaths", ->
+      onDidChangePathsSpy = jasmine.createSpy('onDidChangePaths spy')
+      atom.project.onDidChangePaths(onDidChangePathsSpy)
+
+      [oldPath] = atom.project.getPaths()
+
+      newPath = temp.mkdirSync("dir")
+      atom.project.addPath(newPath)
+
+      expect(onDidChangePathsSpy.callCount).toBe 1
+      expect(onDidChangePathsSpy.mostRecentCall.args[0]).toEqual([oldPath, newPath])
+
   describe ".relativize(path)", ->
     it "returns the path, relative to whichever root directory it is inside of", ->
       rootPath = atom.project.getPaths()[0]

src/project.coffee

@@ -165,22 +165,7 @@ class Project extends Model
     @rootDirectories = []
     @repositories = []
 
-    for projectPath, i in projectPaths
-      projectPath = path.normalize(projectPath)
-
-      directoryPath = if fs.isDirectorySync(projectPath)
-        projectPath
-      else
-        path.dirname(projectPath)
-
-      directory = new Directory(directoryPath)
-      @rootDirectories.push(directory)
-
-      # For now, use only the repositoryProviders with a sync API.
-      repo = null
-      for provider in @repositoryProviders
-        break if repo = provider.repositoryForDirectorySync?(directory)
-      @repositories.push(repo ? null)
+    @addPath(projectPath, emitEvent: false) for projectPath in projectPaths
 
     @emit "path-changed"
     @emitter.emit 'did-change-paths', projectPaths
@@ -189,6 +174,28 @@ class Project extends Model
     Grim.deprecate("Use ::setPaths instead")
     @setPaths([path])
 
+  # Public: Add a path the project's list of root paths
+  #
+  # * `projectPath` {String} The path to the directory to add.
+  addPath: (projectPath, options) ->
+    projectPath = path.normalize(projectPath)
+
+    directoryPath = if fs.isDirectorySync(projectPath)
+      projectPath
+    else
+      path.dirname(projectPath)
+    directory = new Directory(directoryPath)
+    @rootDirectories.push(directory)
+
+    repo = null
+    for provider in @repositoryProviders
+      break if repo = provider.repositoryForDirectorySync?(directory)
+    @repositories.push(repo ? null)
+
+    unless options?.emitEvent is false
+      @emit "path-changed"
+      @emitter.emit 'did-change-paths', @getPaths()
+
   # Public: Get an {Array} of {Directory}s associated with this project.
   getDirectories: ->
     @rootDirectories