Get window size

api/window.go

@@ -19,3 +19,17 @@ func (w *Window) SetSize(width, height int) error {
 
 	return w.Send("POST", "size", request, nil)
 }
+
+func (w *Window) GetSize() (width int, height int, err error) {
+	request := struct {
+		Width  int `json:"width"`
+		Height int `json:"height"`
+	}{}
+
+
+	if err := w.Send("GET", "size", nil, &request); err != nil {
+		return 0, 0 , err
+	}
+
+	return request.Width, request.Height, nil
+}

api/window_test.go

@@ -59,4 +59,23 @@ var _ = Describe("Window", func() {
 			})
 		})
 	})
+
+	Describe("#GetSize", func() {
+		It("should successfully send a GET request to the size endpoint", func() {
+			width, height, err := window.GetSize()
+			Expect(err).To(Succeed())
+			Expect(width).To(BeNumerically(">=", 0))
+			Expect(height).To(BeNumerically(">=", 0))
+			Expect(bus.SendCall.Method).To(Equal("GET"))
+			Expect(bus.SendCall.Endpoint).To(Equal("window/some-id/size"))
+		})
+
+		Context("when the bus indicates a failure", func() {
+			It("should return an error", func() {
+				bus.SendCall.Err = errors.New("some error")
+				_, _, err := window.GetSize()
+				Expect(err).To(MatchError("some error"))
+			})
+		})
+	})
 })

page.go

@@ -209,6 +209,20 @@ func (p *Page) Size(width, height int) error {
 	return nil
 }
 
+// GetSize gets the current page size in pixels.
+func (p *Page) GetSize() (width int, height int, err error) {
+	window, err := p.session.GetWindow()
+	if err != nil {
+		return 0, 0, fmt.Errorf("failed to retrieve window: %s", err)
+	}
+
+	if width, height, err = window.GetSize(); err != nil {
+		return 0, 0, fmt.Errorf("failed to get window size: %s", err)
+	}
+
+	return width, height, nil
+}
+
 // Screenshot takes a screenshot and saves it to the provided filename.
 // The provided filename may be an absolute or relative path.
 func (p *Page) Screenshot(filename string) error {

page_test.go

@@ -336,7 +336,7 @@ var _ = Describe("Page", func() {
 			})
 		})
 
-		Context("when the window fails to retrieve its size", func() {
+		Context("when the window fails to set its size", func() {
 			It("should return an error", func() {
 				session.GetWindowCall.ReturnWindow = window
 				bus.SendCall.Err = errors.New("some error")
@@ -345,6 +345,43 @@ var _ = Describe("Page", func() {
 		})
 	})
 
+	Describe("#GetSize", func() {
+		var (
+			bus    *mocks.Bus
+			window *api.Window
+		)
+
+		BeforeEach(func() {
+			bus = &mocks.Bus{}
+			window = &api.Window{Session: &api.Session{Bus: bus}}
+		})
+
+		It("should get the window width and height", func() {
+			session.GetWindowCall.ReturnWindow = window
+			width, height, err := page.GetSize()
+			Expect(err).To(Succeed())
+			Expect(width).To(BeNumerically(">=", 0))
+			Expect(height).To(BeNumerically(">=", 0))
+		})
+
+		Context("when the session fails to retrieve a window", func() {
+			It("should return an error", func() {
+				session.GetWindowCall.Err = errors.New("some error")
+				_, _, err := page.GetSize()
+				Expect(err).To(MatchError("failed to retrieve window: some error"))
+			})
+		})
+
+		Context("when the window fails to retrieve its size", func() {
+			It("should return an error", func() {
+				session.GetWindowCall.ReturnWindow = window
+				bus.SendCall.Err = errors.New("some error")
+				_, _, err := page.GetSize()
+				Expect(err).To(MatchError("failed to get window size: some error"))
+			})
+		})
+	})
+
 	Describe("#Screenshot", func() {
 		It("should successfully saves the screenshot", func() {
 			session.GetScreenshotCall.ReturnImage = []byte("some-image")