Add ability to modify a selector

lib/capybara.rb

@@ -37,24 +37,24 @@ module Capybara
     #
     # === Configurable options
     #
-    # [app_host = String]                 The default host to use when giving a relative URL to visit  
+    # [app_host = String]                 The default host to use when giving a relative URL to visit
-    # [always_include_port = Boolean]     Whether the Rack server's port should automatically be inserted into every visited URL (Default: false)  
+    # [always_include_port = Boolean]     Whether the Rack server's port should automatically be inserted into every visited URL (Default: false)
-    # [asset_host = String]               Where dynamic assets are hosted - will be prepended to relative asset locations if present (Default: nil)  
+    # [asset_host = String]               Where dynamic assets are hosted - will be prepended to relative asset locations if present (Default: nil)
-    # [run_server = Boolean]              Whether to start a Rack server for the given Rack app (Default: true)  
+    # [run_server = Boolean]              Whether to start a Rack server for the given Rack app (Default: true)
-    # [raise_server_errors = Boolean]     Should errors raised in the server be raised in the tests? (Default: true)  
+    # [raise_server_errors = Boolean]     Should errors raised in the server be raised in the tests? (Default: true)
-    # [server_errors = Array\<Class\>]    Error classes that should be raised in the tests if they are raised in the server and Capybara.raise_server_errors is true (Default: [StandardError])  
+    # [server_errors = Array\<Class\>]    Error classes that should be raised in the tests if they are raised in the server and Capybara.raise_server_errors is true (Default: [StandardError])
-    # [default_selector = :css/:xpath]    Methods which take a selector use the given type by default (Default: :css)  
+    # [default_selector = :css/:xpath]    Methods which take a selector use the given type by default (Default: :css)
-    # [default_max_wait_time = Numeric]   The maximum number of seconds to wait for asynchronous processes to finish (Default: 2)  
+    # [default_max_wait_time = Numeric]   The maximum number of seconds to wait for asynchronous processes to finish (Default: 2)
-    # [ignore_hidden_elements = Boolean]  Whether to ignore hidden elements on the page (Default: true)  
+    # [ignore_hidden_elements = Boolean]  Whether to ignore hidden elements on the page (Default: true)
-    # [automatic_reload = Boolean]        Whether to automatically reload elements as Capybara is waiting (Default: true)  
+    # [automatic_reload = Boolean]        Whether to automatically reload elements as Capybara is waiting (Default: true)
-    # [save_and_open_page_path = String]  Where to put pages saved through save_and_open_page (Default: Dir.pwd)  
+    # [save_and_open_page_path = String]  Where to put pages saved through save_and_open_page (Default: Dir.pwd)
-    # [wait_on_first_by_default = Boolean]   Whether Node#first defaults to Capybara waiting behavior for at least 1 element to match (Default: false) 
+    # [wait_on_first_by_default = Boolean]   Whether Node#first defaults to Capybara waiting behavior for at least 1 element to match (Default: false)
     # === DSL Options
     #
     # when using capybara/dsl, the following options are also available:
     #
-    # [default_driver = Symbol]           The name of the driver to use by default. (Default: :rack_test)  
+    # [default_driver = Symbol]           The name of the driver to use by default. (Default: :rack_test)
-    # [javascript_driver = Symbol]        The name of a driver to use for JavaScript enabled tests. (Default: :selenium)  
+    # [javascript_driver = Symbol]        The name of a driver to use for JavaScript enabled tests. (Default: :selenium)
     #
     def configure
       yield self
@@ -109,6 +109,23 @@ module Capybara
       Capybara::Selector.add(name, &block)
     end
 
+    ##
+    #
+    # Modify a selector previously craeated by {Capybara.add_selector}.
+    # For example modifying the :button selector to also find divs styled
+    # to look like buttons might look like this
+    #
+    #     Capybara.modfiy_selector(:button) do
+    #       xpath { |locator| XPath::HTML.button(locator).or(XPath::css('div.btn')[XPath::string.n.is(locator)]) }
+    #     end
+    #
+    # @param [Symbol] name    The name of the selector to modify
+    # @yield                  A block executed in the context of the existing {Capybara::Selector}
+    #
+    def modify_selector(name, &block)
+      Capybara::Selector.update(name, &block)
+    end
+
     def drivers
       @drivers ||= {}
     end
@@ -305,13 +322,13 @@ module Capybara
         end
       end
     end
-    
+
     # @deprecated Use default_max_wait_time instead
     def default_wait_time
       deprecate('default_wait_time', 'default_max_wait_time', true)
       default_max_wait_time
     end
-    
+
     # @deprecated Use default_max_wait_time= instead
     def default_wait_time=(t)
       deprecate('default_wait_time=', 'default_max_wait_time=')
@@ -357,7 +374,7 @@ module Capybara
   require 'capybara/queries/text_query'
   require 'capybara/queries/title_query'
   require 'capybara/queries/current_path_query'
-  
+
   require 'capybara/node/finders'
   require 'capybara/node/matchers'
   require 'capybara/node/actions'

lib/capybara/selector.rb

@@ -49,6 +49,10 @@ module Capybara
         all[name.to_sym] = Capybara::Selector.new(name.to_sym, &block)
       end
 
+      def update(name, &block)
+        all[name.to_sym].instance_eval(&block)
+      end
+
       def remove(name)
         all.delete(name.to_sym)
       end
@@ -65,15 +69,19 @@ module Capybara
     end
 
     def xpath(&block)
-      @format = :xpath
+      if block
-      @xpath = block if block
+        @format = :xpath
+        @xpath, @css = block, nil
+      end
       @xpath
     end
 
     # Same as xpath, but wrap in XPath.css().
     def css(&block)
-      @format = :css
+      if block
-      @css = block if block
+        @format = :css
+        @css, @xpath = block, nil
+      end
       @css
     end
 

spec/selector_spec.rb

@@ -0,0 +1,53 @@
+require 'spec_helper'
+
+RSpec.describe Capybara do
+  describe 'Selectors' do
+    let :string do
+      Capybara.string <<-STRING
+        <html>
+          <head>
+            <title>selectors</title>
+          </head>
+          <body>
+            <div class="a" id="page">
+              <div class="b" id="content">
+                <h1 class="a">Totally awesome</h1>
+                <p>Yes it is</p>
+              </div>
+              <p class="b">Some Content</p>
+              <p class="b"></p>
+            </div>
+          </body>
+        </html>
+      STRING
+    end
+
+    before do
+      Capybara.add_selector :custom_selector do
+        css { |css_class| "div.#{css_class}" }
+        filter(:not_empty, boolean: true, default: true, skip_if: :all) { |node, value| value ^ (node.text == '') }
+      end
+    end
+
+    describe "modfiy_selector" do
+      it "allows modifying a selector" do
+        el = string.find(:custom_selector, 'a')
+        expect(el.tag_name).to eq 'div'
+        Capybara.modify_selector :custom_selector do
+          css { |css_class| "h1.#{css_class}" }
+        end
+        el = string.find(:custom_selector, 'a')
+        expect(el.tag_name).to eq 'h1'
+      end
+
+      it "doesn't change existing filters" do
+        Capybara.modify_selector :custom_selector do
+          css { |css_class| "p.#{css_class}"}
+        end
+        expect(string).to have_selector(:custom_selector, 'b', count: 1)
+        expect(string).to have_selector(:custom_selector, 'b', not_empty: false, count: 1)
+        expect(string).to have_selector(:custom_selector, 'b', not_empty: :all, count: 2)
+      end
+    end
+  end
+end