Implement Page#emulate_cpu_throttling

docs/api_coverage.md

@@ -81,7 +81,7 @@
 * createPDFStream => `#create_pdf_stream`
 * deleteCookie => `#delete_cookie`
 * emulate
-* ~~emulateCPUThrottling~~
+* emulateCPUThrottling => `#emulate_cpu_throttling`
 * emulateIdleState => `#emulate_idle_state`
 * emulateMediaFeatures => `#emulate_media_features`
 * emulateMediaType => `#emulate_media_type`

lib/puppeteer/page.rb

@@ -799,6 +799,15 @@ def emulate_media_type(media_type)
     @client.send_message('Emulation.setEmulatedMedia', media: media_type_str)
   end
 
+  # @param factor [Number|nil] Factor at which the CPU will be throttled (2x, 2.5x. 3x, ...). Passing `nil` disables cpu throttling.
+  def emulate_cpu_throttling(factor)
+    if factor.nil? || factor >= 1
+      @client.send_message('Emulation.setCPUThrottlingRate', rate: factor || 1)
+    else
+      raise ArgumentError.new('Throttling rate should be greater or equal to 1')
+    end
+  end
+
   # @param features [Array]
   def emulate_media_features(features)
     if features.nil?

spec/integration/emulation_spec.rb

@@ -228,4 +228,11 @@
       expect { page.emulate_vision_deficiency('invalid') }.to raise_error(/Unsupported vision deficiency: invalid/)
     end
   end
+
+  describe 'Page.emulateCPUThrottling', skip: Puppeteer.env.firefox? do
+    it 'should change the CPU throttling rate successfully' do
+      page.emulate_cpu_throttling(100)
+      page.emulate_cpu_throttling(nil)
+    end
+  end
 end