Allow Banner to be rendered as a section

.changeset/nine-turtles-love.md

@@ -0,0 +1,5 @@
+---
+"@primer/view-components": patch
+---
+
+Allow `Banner` to be rendered as a section

app/components/primer/alpha/banner.rb

@@ -26,6 +26,9 @@ class Banner < Primer::Component
         }
       }
 
+      DEFAULT_TAG = :div
+      TAG_OPTIONS = [DEFAULT_TAG, :section].freeze
+
       DEFAULT_SCHEME = :default
       SCHEME_MAPPINGS = {
         DEFAULT_SCHEME => "",
@@ -57,6 +60,7 @@ class Banner < Primer::Component
 
       DEFAULT_DISMISS_LABEL = "Dismiss"
 
+      # @param tag [Symbol] <%= one_of(Primer::Alpha::Banner::TAG_OPTIONS) %>
       # @param full [Boolean] Whether the component should take up the full width of the screen.
       # @param full_when_narrow [Boolean] Whether the component should take up the full width of the screen when rendered inside smaller viewports.
       # @param dismiss_scheme [Symbol] Whether the component can be dismissed with an "x" button. <%= one_of(Primer::Alpha::Banner::DISMISS_SCHEMES) %>
@@ -65,15 +69,15 @@ class Banner < Primer::Component
       # @param icon [Symbol] The name of an <%= link_to_octicons %> icon to use. If no icon is provided, a default one will be chosen based on the scheme.
       # @param scheme [Symbol] <%= one_of(Primer::Alpha::Banner::SCHEME_MAPPINGS.keys) %>
       # @param system_arguments [Hash] <%= link_to_system_arguments_docs %>
-      def initialize(full: false, full_when_narrow: false, dismiss_scheme: DEFAULT_DISMISS_SCHEME, dismiss_label: DEFAULT_DISMISS_LABEL, description: nil, icon: nil, scheme: DEFAULT_SCHEME, **system_arguments)
+      def initialize(tag: DEFAULT_TAG, full: false, full_when_narrow: false, dismiss_scheme: DEFAULT_DISMISS_SCHEME, dismiss_label: DEFAULT_DISMISS_LABEL, description: nil, icon: nil, scheme: DEFAULT_SCHEME, **system_arguments)
         @scheme = fetch_or_fallback(SCHEME_MAPPINGS.keys, scheme, DEFAULT_SCHEME)
         @icon = icon || DEFAULT_ICONS[@scheme]
         @dismiss_scheme = dismiss_scheme
         @dismiss_label = dismiss_label
         @description = description
 
-        @system_arguments = deny_tag_argument(**system_arguments)
-        @system_arguments[:tag] = :div
+        @system_arguments = system_arguments
+        @system_arguments[:tag] = fetch_or_fallback(TAG_OPTIONS, tag, DEFAULT_TAG)
         @system_arguments[:classes] = class_names(
           @system_arguments[:classes],
           "Banner",

test/components/alpha/banner_test.rb

@@ -19,6 +19,18 @@ def test_renders
     assert_selector(".octicon")
   end
 
+  def test_default_renders_as_div
+    render_inline(Primer::Alpha::Banner.new) { "foo" }
+
+    assert_selector("div.Banner")
+  end
+
+  def test_renders_as_section
+    render_inline(Primer::Alpha::Banner.new(tag: :section)) { "foo" }
+
+    assert_selector("section.Banner")
+  end
+
   def test_includes_legacy_classes
     render_inline(Primer::Alpha::Banner.new) { "foo" }