LibWeb: Replace ARIA role static FlyStrings with an enum

This replaces the FlyStrings for ARIA roles that were constructed in
a [[gnu::constructor]] with a single enum. I came across this as the
DOM inspector was crashing due to a null FlyString for an ARIA role.

After fixing that, I was confused as to why these roles were not an
enum. Looking at the spec there's a fixed list of roles and switching
from references to static strings to an enum was pretty much an
exercise in find and replace :).

No functional changes (outside of fixing the mentioned crash).

Userland/Libraries/LibWeb/DOM/ARIAMixin.cpp

@@ -5,13 +5,13 @@
  */
 
 #include <LibWeb/DOM/ARIAMixin.h>
-#include <LibWeb/DOM/ARIARoleNames.h>
+#include <LibWeb/DOM/ARIARoles.h>
 #include <LibWeb/Infra/CharacterTypes.h>
 
 namespace Web::DOM {
 
 // https://www.w3.org/TR/wai-aria-1.2/#introroles
-DeprecatedFlyString ARIAMixin::role_or_default() const
+Optional<ARIARoles::Role> ARIAMixin::role_or_default() const
 {
     // 1. Use the rules of the host language to detect that an element has a role attribute and to identify the attribute value string for it.
     auto role_string = role();
@@ -20,10 +20,13 @@ DeprecatedFlyString ARIAMixin::role_or_default() const
     auto role_list = role_string.split_view(Infra::is_ascii_whitespace);
 
     // 3. Compare the substrings to all the names of the non-abstract WAI-ARIA roles. Case-sensitivity of the comparison inherits from the case-sensitivity of the host language.
-    for (auto const& role : role_list) {
+    for (auto const& role_name : role_list) {
         // 4. Use the first such substring in textual order that matches the name of a non-abstract WAI-ARIA role.
-        if (ARIARoleNames::is_non_abstract_aria_role(role))
-            return role;
+        auto role = ARIARoles::from_string(role_name);
+        if (!role.has_value())
+            continue;
+        if (ARIARoles::is_non_abstract_aria_role(*role))
+            return *role;
     }
 
     // https://www.w3.org/TR/wai-aria-1.2/#document-handling_author-errors_roles

Userland/Libraries/LibWeb/DOM/ARIAMixin.h

@@ -7,6 +7,7 @@
 #pragma once
 
 #include <AK/DeprecatedFlyString.h>
+#include <LibWeb/DOM/ARIARoles.h>
 #include <LibWeb/WebIDL/ExceptionOr.h>
 
 namespace Web::DOM {
@@ -132,9 +133,9 @@ public:
     virtual WebIDL::ExceptionOr<void> set_aria_value_text(DeprecatedString const&) = 0;
 
     // https://www.w3.org/TR/html-aria/#docconformance
-    virtual DeprecatedFlyString default_role() const { return {}; };
+    virtual Optional<ARIARoles::Role> default_role() const { return {}; };
 
-    DeprecatedFlyString role_or_default() const;
+    Optional<ARIARoles::Role> role_or_default() const;
 
     // https://www.w3.org/TR/wai-aria-1.2/#tree_exclusion
     virtual bool exclude_from_accessibility_tree() const = 0;

Userland/Libraries/LibWeb/DOM/ARIARoleNames.cpp

@@ -1,167 +0,0 @@
-/*
- * Copyright (c) 2022, Jonah Shafran <jonahshafran@gmail.com>
- *
- * SPDX-License-Identifier: BSD-2-Clause
- */
-
-#include <LibWeb/DOM/ARIARoleNames.h>
-
-namespace Web::DOM::ARIARoleNames {
-
-#define __ENUMERATE_ARIA_ROLE(name) DeprecatedFlyString name;
-ENUMERATE_ARIA_ROLES
-#undef __ENUMERATE_ARIA_ROLE
-
-[[gnu::constructor]] static void initialize()
-{
-    static bool s_initialized = false;
-    if (s_initialized)
-        return;
-
-#define __ENUMERATE_ARIA_ROLE(name) name = #name;
-    ENUMERATE_ARIA_ROLES
-#undef __ENUMERATE_ARIA_ROLE
-
-    // Special case for C++ keyword
-    switch_ = "switch";
-    s_initialized = true;
-}
-
-// https://www.w3.org/TR/wai-aria-1.2/#abstract_roles
-bool is_abstract_aria_role(DeprecatedFlyString const& role)
-{
-    return role.is_one_of(
-        ARIARoleNames::command,
-        ARIARoleNames::composite,
-        ARIARoleNames::input,
-        ARIARoleNames::landmark,
-        ARIARoleNames::range,
-        ARIARoleNames::roletype,
-        ARIARoleNames::section,
-        ARIARoleNames::sectionhead,
-        ARIARoleNames::select,
-        ARIARoleNames::structure,
-        ARIARoleNames::widget,
-        ARIARoleNames::window);
-}
-
-// https://www.w3.org/TR/wai-aria-1.2/#widget_roles
-bool is_widget_aria_role(DeprecatedFlyString const& role)
-{
-    return role.to_lowercase().is_one_of(
-        ARIARoleNames::button,
-        ARIARoleNames::checkbox,
-        ARIARoleNames::gridcell,
-        ARIARoleNames::link,
-        ARIARoleNames::menuitem,
-        ARIARoleNames::menuitemcheckbox,
-        ARIARoleNames::option,
-        ARIARoleNames::progressbar,
-        ARIARoleNames::radio,
-        ARIARoleNames::scrollbar,
-        ARIARoleNames::searchbox,
-        ARIARoleNames::separator, // TODO: Only when focusable
-        ARIARoleNames::slider,
-        ARIARoleNames::spinbutton,
-        ARIARoleNames::switch_,
-        ARIARoleNames::tab,
-        ARIARoleNames::tabpanel,
-        ARIARoleNames::textbox,
-        ARIARoleNames::treeitem,
-        ARIARoleNames::combobox,
-        ARIARoleNames::grid,
-        ARIARoleNames::listbox,
-        ARIARoleNames::menu,
-        ARIARoleNames::menubar,
-        ARIARoleNames::radiogroup,
-        ARIARoleNames::tablist,
-        ARIARoleNames::tree,
-        ARIARoleNames::treegrid);
-}
-
-// https://www.w3.org/TR/wai-aria-1.2/#document_structure_roles
-bool is_document_structure_aria_role(DeprecatedFlyString const& role)
-{
-    return role.to_lowercase().is_one_of(
-        ARIARoleNames::application,
-        ARIARoleNames::article,
-        ARIARoleNames::blockquote,
-        ARIARoleNames::caption,
-        ARIARoleNames::cell,
-        ARIARoleNames::columnheader,
-        ARIARoleNames::definition,
-        ARIARoleNames::deletion,
-        ARIARoleNames::directory,
-        ARIARoleNames::document,
-        ARIARoleNames::emphasis,
-        ARIARoleNames::feed,
-        ARIARoleNames::figure,
-        ARIARoleNames::generic,
-        ARIARoleNames::group,
-        ARIARoleNames::heading,
-        ARIARoleNames::img,
-        ARIARoleNames::insertion,
-        ARIARoleNames::list,
-        ARIARoleNames::listitem,
-        ARIARoleNames::math,
-        ARIARoleNames::meter,
-        ARIARoleNames::none,
-        ARIARoleNames::note,
-        ARIARoleNames::paragraph,
-        ARIARoleNames::presentation,
-        ARIARoleNames::row,
-        ARIARoleNames::rowgroup,
-        ARIARoleNames::rowheader,
-        ARIARoleNames::separator, // TODO: Only when not focusable
-        ARIARoleNames::strong,
-        ARIARoleNames::subscript,
-        ARIARoleNames::table,
-        ARIARoleNames::term,
-        ARIARoleNames::time,
-        ARIARoleNames::toolbar,
-        ARIARoleNames::tooltip);
-}
-
-// https://www.w3.org/TR/wai-aria-1.2/#landmark_roles
-bool is_landmark_aria_role(DeprecatedFlyString const& role)
-{
-    return role.to_lowercase().is_one_of(
-        ARIARoleNames::banner,
-        ARIARoleNames::complementary,
-        ARIARoleNames::contentinfo,
-        ARIARoleNames::form,
-        ARIARoleNames::main,
-        ARIARoleNames::navigation,
-        ARIARoleNames::region,
-        ARIARoleNames::search);
-}
-
-// https://www.w3.org/TR/wai-aria-1.2/#live_region_roles
-bool is_live_region_aria_role(DeprecatedFlyString const& role)
-{
-    return role.to_lowercase().is_one_of(
-        ARIARoleNames::alert,
-        ARIARoleNames::log,
-        ARIARoleNames::marquee,
-        ARIARoleNames::status,
-        ARIARoleNames::timer);
-}
-
-// https://www.w3.org/TR/wai-aria-1.2/#window_roles
-bool is_windows_aria_role(DeprecatedFlyString const& role)
-{
-    return role.to_lowercase().is_one_of(
-        ARIARoleNames::alertdialog,
-        ARIARoleNames::dialog);
-}
-
-bool is_non_abstract_aria_role(DeprecatedFlyString const& role)
-{
-    return is_widget_aria_role(role)
-        || is_document_structure_aria_role(role)
-        || is_landmark_aria_role(role)
-        || is_live_region_aria_role(role)
-        || is_windows_aria_role(role);
-}
-
-}

Userland/Libraries/LibWeb/DOM/ARIARoles.cpp

@@ -0,0 +1,172 @@
+/*
+ * Copyright (c) 2022, Jonah Shafran <jonahshafran@gmail.com>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <AK/GenericShorthands.h>
+#include <LibWeb/DOM/ARIARoles.h>
+
+namespace Web::DOM::ARIARoles {
+
+StringView role_name(Role role)
+{
+    switch (role) {
+#define __ENUMERATE_ARIA_ROLE(name) \
+    case Role::name:                \
+        return #name##sv;
+        ENUMERATE_ARIA_ROLES
+#undef __ENUMERATE_ARIA_ROLE
+    default:
+        VERIFY_NOT_REACHED();
+    }
+}
+
+Optional<Role> from_string(StringView role_name)
+{
+#define __ENUMERATE_ARIA_ROLE(name)                \
+    if (role_name.equals_ignoring_case(#name##sv)) \
+        return Role::name;
+    ENUMERATE_ARIA_ROLES
+#undef __ENUMERATE_ARIA_ROLE
+    return {};
+}
+
+// https://www.w3.org/TR/wai-aria-1.2/#abstract_roles
+bool is_abstract_aria_role(Role role)
+{
+    return first_is_one_of(role,
+        Role::command,
+        Role::composite,
+        Role::input,
+        Role::landmark,
+        Role::range,
+        Role::roletype,
+        Role::section,
+        Role::sectionhead,
+        Role::select,
+        Role::structure,
+        Role::widget,
+        Role::window);
+}
+
+// https://www.w3.org/TR/wai-aria-1.2/#widget_roles
+bool is_widget_aria_role(Role role)
+{
+    return first_is_one_of(role,
+        Role::button,
+        Role::checkbox,
+        Role::gridcell,
+        Role::link,
+        Role::menuitem,
+        Role::menuitemcheckbox,
+        Role::option,
+        Role::progressbar,
+        Role::radio,
+        Role::scrollbar,
+        Role::searchbox,
+        Role::separator, // TODO: Only when focusable
+        Role::slider,
+        Role::spinbutton,
+        Role::switch_,
+        Role::tab,
+        Role::tabpanel,
+        Role::textbox,
+        Role::treeitem,
+        Role::combobox,
+        Role::grid,
+        Role::listbox,
+        Role::menu,
+        Role::menubar,
+        Role::radiogroup,
+        Role::tablist,
+        Role::tree,
+        Role::treegrid);
+}
+
+// https://www.w3.org/TR/wai-aria-1.2/#document_structure_roles
+bool is_document_structure_aria_role(Role role)
+{
+    return first_is_one_of(role,
+        Role::application,
+        Role::article,
+        Role::blockquote,
+        Role::caption,
+        Role::cell,
+        Role::columnheader,
+        Role::definition,
+        Role::deletion,
+        Role::directory,
+        Role::document,
+        Role::emphasis,
+        Role::feed,
+        Role::figure,
+        Role::generic,
+        Role::group,
+        Role::heading,
+        Role::img,
+        Role::insertion,
+        Role::list,
+        Role::listitem,
+        Role::math,
+        Role::meter,
+        Role::none,
+        Role::note,
+        Role::paragraph,
+        Role::presentation,
+        Role::row,
+        Role::rowgroup,
+        Role::rowheader,
+        Role::separator, // TODO: Only when not focusable
+        Role::strong,
+        Role::subscript,
+        Role::table,
+        Role::term,
+        Role::time,
+        Role::toolbar,
+        Role::tooltip);
+}
+
+// https://www.w3.org/TR/wai-aria-1.2/#landmark_roles
+bool is_landmark_aria_role(Role role)
+{
+    return first_is_one_of(role,
+        Role::banner,
+        Role::complementary,
+        Role::contentinfo,
+        Role::form,
+        Role::main,
+        Role::navigation,
+        Role::region,
+        Role::search);
+}
+
+// https://www.w3.org/TR/wai-aria-1.2/#live_region_roles
+bool is_live_region_aria_role(Role role)
+{
+    return first_is_one_of(role,
+        Role::alert,
+        Role::log,
+        Role::marquee,
+        Role::status,
+        Role::timer);
+}
+
+// https://www.w3.org/TR/wai-aria-1.2/#window_roles
+bool is_windows_aria_role(Role role)
+{
+    return first_is_one_of(role,
+        Role::alertdialog,
+        Role::dialog);
+}
+
+bool is_non_abstract_aria_role(Role role)
+{
+    return is_widget_aria_role(role)
+        || is_document_structure_aria_role(role)
+        || is_landmark_aria_role(role)
+        || is_live_region_aria_role(role)
+        || is_windows_aria_role(role);
+}
+
+}

Userland/Libraries/LibWeb/DOM/ARIARoles.h

@@ -8,7 +8,7 @@
 
 #include <AK/DeprecatedFlyString.h>
 
-namespace Web::DOM::ARIARoleNames {
+namespace Web::DOM::ARIARoles {
 
 #define ENUMERATE_ARIA_ROLES                \
     __ENUMERATE_ARIA_ROLE(alert)            \
@@ -106,17 +106,22 @@ namespace Web::DOM::ARIARoleNames {
     __ENUMERATE_ARIA_ROLE(widget)           \
     __ENUMERATE_ARIA_ROLE(window)
 
-#define __ENUMERATE_ARIA_ROLE(name) extern DeprecatedFlyString name;
-ENUMERATE_ARIA_ROLES
+enum class Role {
+#define __ENUMERATE_ARIA_ROLE(name) name,
+    ENUMERATE_ARIA_ROLES
 #undef __ENUMERATE_ARIA_ROLE
+};
 
-bool is_abstract_aria_role(DeprecatedFlyString const&);
-bool is_widget_aria_role(DeprecatedFlyString const&);
-bool is_document_structure_aria_role(DeprecatedFlyString const&);
-bool is_landmark_aria_role(DeprecatedFlyString const&);
-bool is_live_region_aria_role(DeprecatedFlyString const&);
-bool is_windows_aria_role(DeprecatedFlyString const&);
+StringView role_name(Role);
+Optional<Role> from_string(StringView role_name);
 
-bool is_non_abstract_aria_role(DeprecatedFlyString const&);
+bool is_abstract_aria_role(Role);
+bool is_widget_aria_role(Role);
+bool is_document_structure_aria_role(Role);
+bool is_landmark_aria_role(Role);
+bool is_live_region_aria_role(Role);
+bool is_windows_aria_role(Role);
+
+bool is_non_abstract_aria_role(Role);
 
 }

Userland/Libraries/LibWeb/DOM/AccessibilityTreeNode.cpp

@@ -35,10 +35,10 @@ void AccessibilityTreeNode::serialize_tree_as_json(JsonObjectSerializer<StringBu
             MUST(object.add("type"sv, "element"sv));
 
             auto role = element->role_or_default();
-            bool has_role = !role.is_null() && !role.is_empty() && !ARIARoleNames::is_abstract_aria_role(role);
+            bool has_role = role.has_value() && !ARIARoles::is_abstract_aria_role(*role);
 
             if (has_role)
-                MUST(object.add("role"sv, role.view()));
+                MUST(object.add("role"sv, ARIARoles::role_name(*role)));
             else
                 MUST(object.add("role"sv, ""sv));
         } else {

Userland/Libraries/LibWeb/DOM/Element.cpp

@@ -1282,8 +1282,8 @@ bool Element::exclude_from_accessibility_tree() const
 
     // Elements with none or presentation as the first role in the role attribute. However, their exclusion is conditional. In addition, the element's descendants and text content are generally included. These exceptions and conditions are documented in the presentation (role) section.
     // FIXME: Handle exceptions to excluding presentation role
-    auto role = role_or_default().to_lowercase();
-    if (role == ARIARoleNames::none || role == ARIARoleNames::presentation)
+    auto role = role_or_default();
+    if (role == ARIARoles::Role::none || role == ARIARoles::Role::presentation)
         return true;
 
     // TODO: If not already excluded from the accessibility tree per the above rules, user agents SHOULD NOT include the following elements in the accessibility tree:
@@ -1322,7 +1322,7 @@ bool Element::include_in_accessibility_tree() const
     // Elements that have an explicit role or a global WAI-ARIA attribute and do not have aria-hidden set to true. (See Excluding Elements in the Accessibility Tree for additional guidance on aria-hidden.)
     // NOTE: The spec says only explicit roles count, but playing around in other browsers, this does not seem to be true in practice (for example button elements are always exposed with their implicit role if none is set)
     //       This issue https://github.com/w3c/aria/issues/1851 seeks clarification on this point
-    if ((!role_or_default().is_empty() || has_global_aria_attribute()) && aria_hidden() != "true")
+    if ((role_or_default().has_value() || has_global_aria_attribute()) && aria_hidden() != "true")
         return true;
 
     // TODO: Elements that are not hidden and have an ID that is referenced by another element via a WAI-ARIA property.

Userland/Libraries/LibWeb/DOM/Node.h

@@ -12,7 +12,7 @@
 #include <AK/RefPtr.h>
 #include <AK/TypeCasts.h>
 #include <AK/Vector.h>
-#include <LibWeb/DOM/ARIARoleNames.h>
+#include <LibWeb/DOM/ARIARoles.h>
 #include <LibWeb/DOM/AccessibilityTreeNode.h>
 #include <LibWeb/DOM/EventTarget.h>
 #include <LibWeb/DOMParsing/XMLSerializer.h>