[rb] add support for element screenshots (#8533)

Extracts TakesScreenshot from DriverExtensions to apply it to Element too

rb/lib/selenium/webdriver/chrome/driver.rb

@@ -30,7 +30,6 @@ class Driver < WebDriver::Driver
         include DriverExtensions::HasNetworkConditions
         include DriverExtensions::HasWebStorage
         include DriverExtensions::HasLocation
-        include DriverExtensions::TakesScreenshot
         include DriverExtensions::DownloadsFiles
         include DriverExtensions::HasDevTools
         include DriverExtensions::HasAuthentication

rb/lib/selenium/webdriver/common.rb

@@ -50,7 +50,6 @@
 require 'selenium/webdriver/common/html5/shared_web_storage'
 require 'selenium/webdriver/common/html5/local_storage'
 require 'selenium/webdriver/common/html5/session_storage'
-require 'selenium/webdriver/common/driver_extensions/takes_screenshot'
 require 'selenium/webdriver/common/driver_extensions/rotatable'
 require 'selenium/webdriver/common/driver_extensions/has_web_storage'
 require 'selenium/webdriver/common/driver_extensions/downloads_files'
@@ -69,5 +68,6 @@
 require 'selenium/webdriver/common/keys'
 require 'selenium/webdriver/common/profile_helper'
 require 'selenium/webdriver/common/options'
+require 'selenium/webdriver/common/takes_screenshot'
 require 'selenium/webdriver/common/driver'
 require 'selenium/webdriver/common/element'

rb/lib/selenium/webdriver/common/driver.rb

@@ -30,6 +30,7 @@ module WebDriver
 
     class Driver
       include SearchContext
+      include TakesScreenshot
 
       class << self
         #
@@ -360,6 +361,10 @@ def service_url(opts)
         @service = service_config.launch
         @service.uri
       end
+
+      def screenshot
+        bridge.screenshot
+      end
     end # Driver
   end # WebDriver
 end # Selenium

rb/lib/selenium/webdriver/common/element.rb

@@ -23,6 +23,7 @@ class Element
       ELEMENT_KEY = 'element-6066-11e4-a52e-4f735466cecf'
 
       include SearchContext
+      include TakesScreenshot
 
       #
       # Creates a new Element
@@ -327,6 +328,10 @@ def selectable?
 
         tn == 'option' || (tn == 'input' && %w[radio checkbox].include?(type))
       end
+
+      def screenshot
+        bridge.element_screenshot(self)
+      end
     end # Element
   end # WebDriver
 end # Selenium

rb/lib/selenium/webdriver/common/takes_screenshot.rb

@@ -0,0 +1,63 @@
+# frozen_string_literal: true
+
+# Licensed to the Software Freedom Conservancy (SFC) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The SFC licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+
+module Selenium
+  module WebDriver
+    #
+    # @api private
+    #
+    module TakesScreenshot
+      #
+      # Save a PNG screenshot to the given path
+      #
+      # @api public
+      #
+
+      def save_screenshot(png_path)
+        extension = File.extname(png_path).downcase
+        if extension != '.png'
+          WebDriver.logger.warn "name used for saved screenshot does not match file type. "\
+                                "It should end with .png extension",
+                                id: :screenshot
+        end
+        File.open(png_path, 'wb') { |f| f << screenshot_as(:png) }
+      end
+
+      #
+      # Return a PNG screenshot in the given format as a string
+      #
+      # @param [:base64, :png] format
+      # @return String screenshot
+      #
+      # @api public
+
+      def screenshot_as(format)
+        case format
+        when :base64
+          screenshot
+        when :png
+          screenshot.unpack1('m')
+        else
+          raise Error::UnsupportedOperationError, "unsupported format: #{format.inspect}"
+        end
+      end
+
+    end # TakesScreenshot
+  end # WebDriver
+end # Selenium

rb/lib/selenium/webdriver/edge_html/driver.rb

@@ -28,7 +28,6 @@ module EdgeHtml
 
       class Driver < WebDriver::Driver
         include DriverExtensions::HasWebStorage
-        include DriverExtensions::TakesScreenshot
 
         def browser
           :edge_html

rb/lib/selenium/webdriver/firefox/driver.rb

@@ -29,7 +29,6 @@ module Firefox
       class Driver < WebDriver::Driver
         include DriverExtensions::HasAddons
         include DriverExtensions::HasWebStorage
-        include DriverExtensions::TakesScreenshot
 
         def browser
           :firefox

rb/lib/selenium/webdriver/ie/driver.rb

@@ -29,7 +29,6 @@ module IE
 
       class Driver < WebDriver::Driver
         include DriverExtensions::HasWebStorage
-        include DriverExtensions::TakesScreenshot
 
         def browser
           :internet_explorer

rb/lib/selenium/webdriver/remote/bridge.rb

@@ -251,6 +251,10 @@ def screenshot
           execute :take_screenshot
         end
 
+        def element_screenshot(element)
+          execute :take_element_screenshot, id: element.ref
+        end
+
         #
         # HTML 5
         #

rb/lib/selenium/webdriver/remote/driver.rb

@@ -28,7 +28,6 @@ module Remote
 
       class Driver < WebDriver::Driver
         include DriverExtensions::UploadsFiles
-        include DriverExtensions::TakesScreenshot
         include DriverExtensions::HasSessionId
         include DriverExtensions::Rotatable
         include DriverExtensions::HasRemoteStatus

rb/lib/selenium/webdriver/safari/driver.rb

@@ -30,7 +30,6 @@ class Driver < WebDriver::Driver
         include DriverExtensions::HasDebugger
         include DriverExtensions::HasPermissions
         include DriverExtensions::HasWebStorage
-        include DriverExtensions::TakesScreenshot
 
         def browser
           :safari

rb/spec/integration/selenium/webdriver/driver_spec.rb

@@ -60,53 +60,6 @@ module WebDriver
         expect(driver.find_element(id: 'dynamo').text).to eq("What's for dinner?")
       end
 
-      context 'screenshots' do
-        it 'should save' do
-          driver.navigate.to url_for('xhtmlTest.html')
-          path = "#{Dir.tmpdir}/test#{SecureRandom.urlsafe_base64}.png"
-
-          save_screenshot_and_assert(path)
-        end
-
-        it 'should warn if extension of provided path is not png' do
-          driver.navigate.to url_for('xhtmlTest.html')
-          path = "#{Dir.tmpdir}/test#{SecureRandom.urlsafe_base64}.jpg"
-          message = "name used for saved screenshot does not match file type. "\
-                    "It should end with .png extension"
-          expect(WebDriver.logger).to receive(:warn).with(message, id: :screenshot)
-
-          save_screenshot_and_assert(path)
-        end
-
-        it 'should not warn if extension of provided path is png' do
-          driver.navigate.to url_for('xhtmlTest.html')
-          path = "#{Dir.tmpdir}/test#{SecureRandom.urlsafe_base64}.PNG"
-          expect(WebDriver.logger).not_to receive(:warn)
-
-          save_screenshot_and_assert(path)
-        end
-
-        it 'should return in the specified format' do
-          driver.navigate.to url_for('xhtmlTest.html')
-
-          ss = driver.screenshot_as(:png)
-          expect(ss).to be_kind_of(String)
-          expect(ss.size).to be_positive
-        end
-
-        it 'raises an error when given an unknown format' do
-          expect { driver.screenshot_as(:jpeg) }.to raise_error(WebDriver::Error::UnsupportedOperationError)
-        end
-
-        def save_screenshot_and_assert(path)
-          driver.save_screenshot path
-          expect(File.exist?(path)).to be true
-          expect(File.size(path)).to be_positive
-        ensure
-          File.delete(path) if File.exist?(path)
-        end
-      end
-
       describe 'one element' do
         it 'should find by id' do
           driver.navigate.to url_for('xhtmlTest.html')

rb/spec/integration/selenium/webdriver/takes_screenshot_spec.rb

@@ -0,0 +1,75 @@
+# frozen_string_literal: true
+
+# Licensed to the Software Freedom Conservancy (SFC) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The SFC licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+
+require_relative 'spec_helper'
+
+module Selenium
+  module WebDriver
+    describe TakesScreenshot do
+      before do
+        driver.navigate.to url_for('xhtmlTest.html')
+      end
+
+      let(:element) { driver.find_element(css: '.content') }
+      let(:path) { "#{Dir.tmpdir}/test#{SecureRandom.urlsafe_base64}.png" }
+
+      it 'should save' do
+        save_screenshots_and_assert(path)
+      end
+
+      it 'should warn if extension of provided path is not png' do
+        jpg_path = "#{Dir.tmpdir}/test#{SecureRandom.urlsafe_base64}.jpg"
+        message = "name used for saved screenshot does not match file type. "\
+                  "It should end with .png extension"
+        expect(WebDriver.logger).to receive(:warn).with(message, id: :screenshot).twice
+
+        save_screenshots_and_assert(jpg_path)
+      end
+
+      it 'should not warn if extension of provided path is png' do
+        expect(WebDriver.logger).not_to receive(:warn)
+
+        save_screenshots_and_assert(path)
+      end
+
+      it 'should return in the specified format' do
+        ss = element.screenshot_as(:png)
+        expect(ss).to be_kind_of(String)
+        expect(ss.size).to be_positive
+      end
+
+      it 'raises an error when given an unknown format' do
+        expect { element.screenshot_as(:jpeg) }.to raise_error(WebDriver::Error::UnsupportedOperationError)
+      end
+
+      def save_screenshots_and_assert(path)
+        save_screenshot_and_assert(driver, path)
+        save_screenshot_and_assert(element, path)
+      end
+
+      def save_screenshot_and_assert(source, path)
+        source.save_screenshot path
+        expect(File.exist?(path)).to be true
+        expect(File.size(path)).to be_positive
+      ensure
+        File.delete(path) if File.exist?(path)
+      end
+    end
+  end
+end