Allow "select" of datalist values from input element

lib/capybara/node/actions.rb

@@ -174,8 +174,42 @@ module Capybara
       #
       # @return [Capybara::Node::Element]  The option element selected
       def select(value = nil, from: nil, **options)
-        scope = from ? find(:select, from, options) : self
-        scope.find(:option, value, options).select_option
+        scope = if from
+          synchronize(Capybara::Queries::BaseQuery.wait(options, session_options.default_max_wait_time)) do
+            begin
+              find(:select, from, options)
+            rescue Capybara::ElementNotFound => select_error
+              raise if %i[selected with_selected multiple].any? { |option| options.key?(option) }
+              begin
+                find(:datalist_input, from, options)
+              rescue Capybara::ElementNotFound => dlinput_error
+                raise Capybara::ElementNotFound, "#{select_error.message} and #{dlinput_error.message}"
+              end
+            end
+          end
+        else
+          self
+        end
+
+        if scope.respond_to?(:tag_name) && scope.tag_name == "input"
+          begin
+            # TODO: this is a more efficient but won't work with non-JS drivers
+            # datalist_options = session.evaluate_script('Array.prototype.slice.call((arguments[0].list||{}).options || []).filter(function(el){ return !el.disabled }).map(function(el){ return { "value": el.value, "label": el.label} })', scope)
+            datalist_options = session.evaluate_script(DATALIST_OPTIONS_SCRIPT, scope)
+            if (option = datalist_options.find { |o| o['value'] == value || o['label'] == value })
+              scope.set(option["value"])
+            else
+              raise ::Capybara::ElementNotFound, "Unable to find datalist option \"#{value}\""
+            end
+          rescue ::Capybara::NotSupportedByDriverError
+            # Implement for drivers that don't support JS
+            datalist = find(:xpath, XPath.descendant(:datalist)[XPath.attr(:id) == scope[:list]], visible: false)
+            option = datalist.find(:datalist_option, value, disabled: false)
+            scope.set(option.value)
+          end
+        else
+          scope.find(:option, value, options).select_option
+        end
       end
 
       ##
@@ -291,6 +325,12 @@ module Capybara
           delete el.capybara_style_cache;
         }
       JS
+
+      DATALIST_OPTIONS_SCRIPT = <<-'JS'.freeze
+        Array.prototype.slice.call((arguments[0].list||{}).options || []).
+          filter(function(el){ return !el.disabled }).
+          map(function(el){ return { "value": el.value, "label": el.label} })
+      JS
     end
   end
 end

lib/capybara/rack_test/node.rb

@@ -90,7 +90,7 @@ class Capybara::RackTest::Node < Capybara::Driver::Node
     return true if string_node.disabled?
 
     if %w[option optgroup].include? tag_name
-      find_xpath("parent::*[self::optgroup or self::select]")[0].disabled?
+      find_xpath("parent::*[self::optgroup or self::select or self::datalist]")[0].disabled?
     else
       !find_xpath("parent::fieldset[@disabled] | ancestor::*[not(self::legend) or preceding-sibling::legend][parent::fieldset[@disabled]]").empty?
     end

lib/capybara/selector.rb

@@ -407,6 +407,34 @@ Capybara.add_selector(:select) do
   end
 end
 
+Capybara.add_selector(:datalist_input) do
+  label "input box with datalist completion"
+
+  xpath do |locator, **options|
+    xpath = XPath.descendant(:input)[XPath.attr(:list)]
+    locate_field(xpath, locator, options)
+  end
+
+  filter_set(:_field, %i[disabled name placeholder])
+
+  filter(:options) do |node, options|
+    actual = node.find("//datalist[@id=#{node[:list]}]", visible: :all).all(:datalist_option, wait: false).map(&:value)
+    options.sort == actual.sort
+  end
+
+  filter(:with_options) do |node, options|
+    options.all? { |option| node.find("//datalist[@id=#{node[:list]}]", visible: :all).first(:datalist_option, option) }
+  end
+
+  describe do |options: nil, with_options: nil, **opts|
+    desc = "".dup
+    desc << " with options #{options.inspect}" if options
+    desc << " with at least options #{with_options.inspect}" if with_options
+    desc << describe_all_expression_filters(opts)
+    desc
+  end
+end
+
 ##
 #
 # Find option elements
@@ -433,6 +461,25 @@ Capybara.add_selector(:option) do
   end
 end
 
+Capybara.add_selector(:datalist_option) do
+  label "datalist option"
+  visible(:all)
+
+  xpath do |locator|
+    xpath = XPath.descendant(:option)
+    xpath = xpath[XPath.string.n.is(locator.to_s) | (XPath.attr(:value) == locator.to_s)] unless locator.nil?
+    xpath
+  end
+
+  filter(:disabled, :boolean) { |node, value| !(value ^ node.disabled?) }
+
+  describe do |**options|
+    desc = "".dup
+    desc << " that is#{' not' unless options[:disabled]} disabled" if options.key?(:disabled)
+    desc
+  end
+end
+
 ##
 #
 # Find file input elements

lib/capybara/spec/session/select_spec.rb

@@ -84,9 +84,35 @@ Capybara::SpecHelper.spec "#select" do
     expect(@session.find_field('Title').value).to eq('Miss')
   end
 
+  context "input with datalist" do
+    it "should select an option" do
+      @session.select("Audi", from: 'manufacturer')
+      @session.click_button('awesome')
+      expect(extract_results(@session)['manufacturer']).to eq('Audi')
+    end
+
+    it "should not find an input without a datalist" do
+      expect do
+        @session.select("Thomas", from: 'form_first_name')
+      end.to raise_error(/Unable to find visible input box with datalist completion "form_first_name" that is not disabled/)
+    end
+
+    it "should not select an option that doesn't exist" do
+      expect do
+        @session.select("Tata", from: 'manufacturer')
+      end.to raise_error(/Unable to find datalist option "Tata"/)
+    end
+
+    it "should not select a disabled option" do
+      expect do
+        @session.select("Mercedes", from: 'manufacturer')
+      end.to raise_error(/Unable to find datalist option "Mercedes"/)
+    end
+  end
+
   context "with a locator that doesn't exist" do
     it "should raise an error" do
-      msg = "Unable to find visible select box \"does not exist\" that is not disabled"
+      msg = /Unable to find visible select box "does not exist" that is not disabled/
       expect do
         @session.select('foo', from: 'does not exist')
       end.to raise_error(Capybara::ElementNotFound, msg)

lib/capybara/spec/views/form.erb

@@ -197,6 +197,15 @@ New line after and before textarea tag
     </label>
   </p>
 
+  <p>
+    <input type="text" name="form[manufacturer]" list="manufacturers" id="manufacturer"/>
+    <datalist id="manufacturers">
+      <option value="Jaguar">J</option>
+      <option value="Audi">
+      <option value="Mercedes" disabled>
+    </datalist>
+  </p>
+
   <p>
     <input type="checkbox" name="form[valueless_checkbox]" id="valueless_checkbox" checked="checked"/>
     <label for="valueless_checkbox">Valueless Checkbox</label>