Add ability to save and open screenshot

This adds a new method `save_and_open_screenshot` that saves the screenshot then
opens it for inspection.

Refactor duplicate logic for `save_and_open_page` and `save_and_open_screenshot`

README.md

@@ -507,6 +507,12 @@ Finally, in drivers that support it, you can save a screenshot:
 page.save_screenshot('screenshot.png')
 ```
 
+Or have it save and automatically open:
+
+```ruby
+save_and_open_screenshot
+```
+
 ## Matching
 
 It is possible to customize how Capybara finds elements. At your disposal

lib/capybara/session.rb

@@ -42,8 +42,8 @@ class Session
       :execute_script, :evaluate_script, :visit, :go_back, :go_forward,
       :within, :within_fieldset, :within_table, :within_frame, :within_window,
       :save_page, :save_and_open_page, :save_screenshot,
-      :reset_session!, :response_headers, :status_code,
-      :title, :has_title?, :has_no_title?, :current_scope
+      :save_and_open_screenshot, :reset_session!, :response_headers,
+      :status_code, :title, :has_title?, :has_no_title?, :current_scope
     ]
     DSL_METHODS = NODE_METHODS + SESSION_METHODS
 
@@ -360,8 +360,7 @@ def evaluate_script(script)
     # @param  [String] path     The path to where it should be saved [optional]
     #
     def save_page(path=nil)
-      path ||= "capybara-#{Time.new.strftime("%Y%m%d%H%M%S")}#{rand(10**10)}.html"
-      path = File.expand_path(path, Capybara.save_and_open_page_path)
+      path ||= default_path('html')
 
       FileUtils.mkdir_p(File.dirname(path))
 
@@ -377,14 +376,7 @@ def save_page(path=nil)
     #
     def save_and_open_page(file_name=nil)
       file_name = save_page(file_name)
-
-      begin
-        require "launchy"
-        Launchy.open(file_name)
-      rescue LoadError
-        warn "Page saved to #{file_name} with save_and_open_page."
-        warn "Please install the launchy gem to open page automatically."
-      end
+      open_file(file_name)
     end
 
     ##
@@ -394,7 +386,23 @@ def save_and_open_page(file_name=nil)
     # @param  [String] path    A string of image path
     # @option [Hash]   options Options for saving screenshot
     def save_screenshot(path, options={})
+      path ||= default_path('png')
+
+      FileUtils.mkdir_p(File.dirname(path))
+
       driver.save_screenshot(path, options)
+      path
+    end
+
+    ##
+    #
+    # Save a screenshot of the page and open it for inspection
+    #
+    # @param  [String] file_name  The path to where it should be saved [optional]
+    #
+    def save_and_open_screenshot(file_name=nil)
+      file_name = save_screenshot(file_name)
+      open_file(file_name)
     end
 
     def document
@@ -440,6 +448,22 @@ def current_scope
 
   private
 
+    def open_file(file_name)
+      begin
+        require "launchy"
+        Launchy.open(file_name)
+      rescue LoadError
+        warn "File saved to #{file_name}."
+        warn "Please install the launchy gem to open the file automatically."
+      end
+    end
+
+    def default_path(extension)
+      timestamp = Time.new.strftime("%Y%m%d%H%M%S")
+      path = "capybara-#{timestamp}#{rand(10**10)}.#{extension}"
+      File.expand_path(path, Capybara.save_and_open_page_path)
+    end
+
     def scopes
       @scopes ||= [document]
     end

lib/capybara/spec/session/save_and_open_screenshot_spec.rb

@@ -0,0 +1,46 @@
+require 'launchy'
+
+Capybara::SpecHelper.spec '#save_and_open_screenshot' do
+  before do
+    @session.visit '/'
+  end
+
+  it 'opens file from the default directory', :requires => [:screenshot] do
+    expected_file_regex = %r{capybara/capybara-\d+\.png}
+    @session.driver.stub(:save_screenshot)
+    Launchy.stub(:open)
+
+    @session.save_and_open_screenshot
+
+    expect(@session.driver).to have_received(:save_screenshot).
+      with(expected_file_regex, {})
+    expect(Launchy).to have_received(:open).with(expected_file_regex)
+  end
+
+  it 'opens file from the provided directory', :requires => [:screenshot] do
+    custom_path = 'screenshots/1.png'
+    @session.driver.stub(:save_screenshot)
+    Launchy.stub(:open)
+
+    @session.save_and_open_screenshot(custom_path)
+
+    expect(@session.driver).to have_received(:save_screenshot).
+      with(custom_path, {})
+    expect(Launchy).to have_received(:open).with(custom_path)
+  end
+
+  context 'when launchy cannot be required' do
+    it 'prints out a correct warning message', :requires => [:screenshot] do
+      file_path = File.join(Dir.tmpdir, 'test.png')
+      @session.stub(:require).with('launchy').and_raise(LoadError)
+      @session.stub(:warn)
+
+      @session.save_and_open_screenshot(file_path)
+
+      expect(@session).to have_received(:warn).
+        with("File saved to #{file_path}.")
+      expect(@session).to have_received(:warn).
+        with('Please install the launchy gem to open the file automatically.')
+    end
+  end
+end

lib/capybara/spec/session/screenshot.rb → lib/capybara/spec/session/screenshot_spec.rb

@@ -4,11 +4,13 @@
 
   before do
     @session.visit '/'
-    @session.save_screenshot image_path
   end
 
   it "should generate PNG file", :requires => [:screenshot] do
+    path = @session.save_screenshot image_path
+
     magic = File.read(image_path, 4)
     expect(magic).to eq "\x89PNG"
+    expect(path).to eq image_path
   end
 end