Add open attribute to component wrapper

- adds the ability to pass an open attribute to the component wrapper helper
- needed for the details component, where open can be passed as true to have the details component expanded by default

CHANGELOG.md

@@ -9,6 +9,7 @@
 
 ## Unreleased
 
+* Add open attribute to component wrapper ([PR #4074](https://github.com/alphagov/govuk_publishing_components/pull/4074))
 * Add guard to accordion component init method ([PR #4069](https://github.com/alphagov/govuk_publishing_components/pull/4069))
 * Prevent screen readers from announcing document list child/parts items dashes ([PR #4066](https://github.com/alphagov/govuk_publishing_components/pull/4066))
 * Align checkboxes component more toward Design System ([PR #4061](https://github.com/alphagov/govuk_publishing_components/pull/4061))

app/models/govuk_publishing_components/component_wrapper_helper_options.rb

@@ -10,6 +10,7 @@ def self.description
 - `classes` - accepts a space separated string of classes, these should not be used for styling and must be prefixed with `js-`
 - `role` - accepts a space separated string of roles
 - `lang` - accepts a language attribute value
+- `open` - accepts an open attribute value (true or false)
       "
     end
   end

docs/component-wrapper-helper.md

@@ -31,6 +31,7 @@ These options can be passed to any component that uses the component wrapper.
 - `classes` - accepts a space separated string of classes, these should not be used for styling and must be prefixed with `js-`
 - `role` - accepts a space separated string of roles
 - `lang` - accepts a language attribute value
+- `open` - accepts an open attribute value (true or false)
 
 To prevent breaking [component isolation](https://github.com/alphagov/govuk_publishing_components/blob/main/docs/component_principles.md#a-component-is-isolated-when), passed classes should only be used for JavaScript hooks and not styling. All component styling should be included only in the component itself. Any passed classes should be prefixed with `js-`. To allow for extending this option, classes prefixed with `gem-c-`, `app-c-` or `govuk-` are also permitted, but should only be used within the component and not passed to it.
 
@@ -71,6 +72,7 @@ The component wrapper includes several methods to make managing options easier,
   component_helper.add_aria_attribute({ label: "my-label" }) # works like 'add_data_attribute'
   component_helper.add_role("button") # works like 'add_class'
   component_helper.set_lang("en") # works like 'set_id' (can only have one lang)
+  component_helper.set_open(true) # can pass true or false
 %>
 <%= tag.div(**component_helper.all_attributes) do %>
   component content

lib/govuk_publishing_components/presenters/component_wrapper_helper.rb

@@ -10,6 +10,7 @@ def initialize(options)
         check_aria_is_valid(@options[:aria]) if @options.include?(:aria)
         check_role_is_valid(@options[:role]) if @options.include?(:role)
         check_lang_is_valid(@options[:lang]) if @options.include?(:lang)
+        check_open_is_valid(@options[:open]) if @options.include?(:open)
       end
 
       def all_attributes
@@ -21,6 +22,7 @@ def all_attributes
         attributes[:class] = @options[:classes] unless @options[:classes].blank?
         attributes[:role] = @options[:role] unless @options[:role].blank?
         attributes[:lang] = @options[:lang] unless @options[:lang].blank?
+        attributes[:open] = @options[:open] unless @options[:open].blank?
 
         attributes
       end
@@ -55,6 +57,11 @@ def set_lang(lang)
         @options[:lang] = lang
       end
 
+      def set_open(open_attribute)
+        check_open_is_valid(open_attribute)
+        @options[:open] = open_attribute
+      end
+
     private
 
       def check_id_is_valid(id)
@@ -114,6 +121,15 @@ def check_lang_is_valid(lang)
         end
       end
 
+      def check_open_is_valid(open_attribute)
+        return if open_attribute.blank?
+
+        options = [true, false]
+        unless options.include? open_attribute
+          raise(ArgumentError, "open attribute (#{open_attribute}) is not recognised")
+        end
+      end
+
       def extend_string(option, string)
         ((@options[option] ||= "") << " #{string}").strip!
       end

spec/lib/govuk_publishing_components/components/component_wrapper_helper_spec.rb

@@ -11,6 +11,7 @@
         },
         role: "navigation",
         lang: "en",
+        open: true,
       }
       component_helper = GovukPublishingComponents::Presenters::ComponentWrapperHelper.new(args)
       expected = {
@@ -23,6 +24,7 @@
         },
         role: "navigation",
         lang: "en",
+        open: true,
       }
       expect(component_helper.all_attributes).to eql(expected)
     end
@@ -167,5 +169,31 @@
         GovukPublishingComponents::Presenters::ComponentWrapperHelper.new(lang: "klingon")
       }.to raise_error(ArgumentError, error)
     end
+
+    it "accepts valid open attribute value" do
+      component_helper = GovukPublishingComponents::Presenters::ComponentWrapperHelper.new(open: true)
+      expected = {
+        open: true,
+      }
+      expect(component_helper.all_attributes).to eql(expected)
+    end
+
+    it "can set an open attribute, overriding a passed value" do
+      helper = GovukPublishingComponents::Presenters::ComponentWrapperHelper.new(open: true)
+      helper.set_open(false)
+      expect(helper.all_attributes[:open]).to eql(nil)
+    end
+
+    it "by default does not include an open attribute" do
+      component_helper = GovukPublishingComponents::Presenters::ComponentWrapperHelper.new(open: false)
+      expect(component_helper.all_attributes).to eql({})
+    end
+
+    it "does not accept an invalid open value" do
+      error = "open attribute (false) is not recognised"
+      expect {
+        GovukPublishingComponents::Presenters::ComponentWrapperHelper.new(open: "false")
+      }.to raise_error(ArgumentError, error)
+    end
   end
 end