Add :valid node filter to :field and :fillable_field selectors

.rubocop.yml

@@ -31,6 +31,7 @@ Metrics/BlockLength:
     - 'capybara.gemspec'
   ExcludedMethods:
     - Capybara.add_selector
+    - Capybara::Selector::FilterSet.add
 
 Metrics/AbcSize:
   Enabled: false

History.md

@@ -5,6 +5,7 @@ Release date: unreleased
 
 * Allow forcing HTML5 or legacy dragging via the `:html5` option to `drag_to` when using Selenium with Chrome or Firefox
 * Autodetection of drag type interprets not seeing the mousedown event as legacy.
+* HTML5 form validation `:valid` node filter added to `:field` and `:fillable_field` selectors
 
 # Version 3.27.0
 Release date: 2019-07-28

lib/capybara/selector.rb

@@ -34,6 +34,7 @@ require 'capybara/selector/definition'
 #       * :unchecked (Boolean) - Match unchecked fields?
 #       * :disabled (Boolean, :all) - Match disabled field? (Default: false)
 #       * :multiple (Boolean) - Match fields that accept multiple values
+#       * :valid (Boolean) - Match fields that are valid/invalid according to HTML5 form validation
 #
 # * **:fieldset** - Select fieldset elements
 #   * Locator: Matches id, {Capybara.configure test_id}, or contents of wrapped legend
@@ -72,6 +73,7 @@ require 'capybara/selector/definition'
 #       * :type (String) - Matches the type attribute of the field or element type for 'textarea'
 #       * :disabled (Boolean, :all) - Match disabled field? (Default: false)
 #       * :multiple (Boolean) - Match fields that accept multiple values
+#       * :valid (Boolean) - Match fields that are valid/invalid according to HTML5 form validation
 #
 # * **:radio_button** - Find radio buttons
 #   * Locator: Match id, {Capybara.configure test_id} attribute, name, or associated label text
@@ -166,6 +168,7 @@ Capybara::Selector::FilterSet.add(:_field) do
   node_filter(:checked, :boolean) { |node, value| !(value ^ node.checked?) }
   node_filter(:unchecked, :boolean) { |node, value| (value ^ node.checked?) }
   node_filter(:disabled, :boolean, default: false, skip_if: :all) { |node, value| !(value ^ node.disabled?) }
+  node_filter(:valid, :boolean) { |node, value| node.evaluate_script('this.validity.valid') == value }
 
   expression_filter(:name) { |xpath, val| xpath[XPath.attr(:name) == val] }
   expression_filter(:placeholder) { |xpath, val| xpath[XPath.attr(:placeholder) == val] }
@@ -182,12 +185,14 @@ Capybara::Selector::FilterSet.add(:_field) do
     desc
   end
 
-  describe(:node_filters) do |checked: nil, unchecked: nil, disabled: nil, **|
+  describe(:node_filters) do |checked: nil, unchecked: nil, disabled: nil, valid: nil, **|
     desc, states = +'', []
     states << 'checked' if checked || (unchecked == false)
     states << 'not checked' if unchecked || (checked == false)
     states << 'disabled' if disabled == true
     desc << " that is #{states.join(' and ')}" unless states.empty?
+    desc << ' that is valid' if valid == true
+    desc << ' that is invalid' if valid == false
     desc
   end
 end

lib/capybara/selector/definition/fillable_field.rb

@@ -18,7 +18,7 @@ Capybara.add_selector(:fillable_field, locator_type: [String, Symbol]) do
     end
   end
 
-  filter_set(:_field, %i[disabled multiple name placeholder])
+  filter_set(:_field, %i[disabled multiple name placeholder valid])
 
   node_filter(:with) do |node, with|
     val = node.value

lib/capybara/spec/session/has_field_spec.rb

@@ -93,6 +93,24 @@ Capybara::SpecHelper.spec '#has_field' do
       expect(@session).not_to have_field('Html5 Multiple Email', multiple: false)
     end
   end
+
+  context 'with valid', requires: [:js] do
+    it 'should be true if field is valid' do
+      @session.fill_in 'required', with: 'something'
+      @session.fill_in 'length', with: 'abcd'
+
+      expect(@session).to have_field('required', valid: true)
+      expect(@session).to have_field('length', valid: true)
+    end
+
+    it 'should be false if field is invalid' do
+      expect(@session).not_to have_field('required', valid: true)
+      expect(@session).to have_field('required', valid: false)
+
+      @session.fill_in 'length', with: 'abc'
+      expect(@session).not_to have_field('length', valid: true)
+    end
+  end
 end
 
 Capybara::SpecHelper.spec '#has_no_field' do

lib/capybara/spec/views/form.erb

@@ -1,7 +1,7 @@
 
 <h1>Form</h1>
 
-<form action="/form" method="post">
+<form action="/form" method="post" novalidate>
 
   <p>
     <label for="form_title">Title</label>
@@ -460,6 +460,11 @@ New line after and before textarea tag
     <input id="readonly" name="form[readonly_test]" readonly/>
     <input id="not_readonly" name="form[readonly_test]" />
   </p>
+
+  <p>
+    <input id="required" name="form[required]" required />
+    <input id="length" name="form[length]" minlength="4" maxlength="4" />
+  </p>
 </form>
 
 <input type="text" name="form[outside_input]" value="outside_input" form="form1"/>