Bug 1839316: part 2) Implement getting and setting "fetchpriority" content attribute of `<script>` element. r=smaug

Differential Revision: https://phabricator.services.mozilla.com/D181752

dom/html/FetchPriority.cpp

@@ -0,0 +1,13 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/dom/FetchPriority.h"
+
+namespace mozilla::dom {
+const char* kFetchPriorityAttributeValueHigh = "high";
+const char* kFetchPriorityAttributeValueLow = "low";
+const char* kFetchPriorityAttributeValueAuto = "auto";
+}  // namespace mozilla::dom

dom/html/FetchPriority.h

@@ -0,0 +1,23 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_dom_FetchPriority_h
+#define mozilla_dom_FetchPriority_h
+
+#include <cstdint>
+
+namespace mozilla::dom {
+
+// <https://html.spec.whatwg.org/multipage/urls-and-fetching.html#fetch-priority-attributes>.
+enum class FetchPriority : uint8_t { High, Low, Auto };
+
+extern const char* kFetchPriorityAttributeValueHigh;
+extern const char* kFetchPriorityAttributeValueLow;
+extern const char* kFetchPriorityAttributeValueAuto;
+
+}  // namespace mozilla::dom
+
+#endif  // mozilla_dom_FetchPriority_h

dom/html/HTMLScriptElement.cpp

@@ -4,6 +4,7 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
+#include "nsAttrValue.h"
 #include "nsGkAtoms.h"
 #include "nsStyleConsts.h"
 #include "mozilla/dom/Document.h"
@@ -18,6 +19,7 @@
 #include "nsDOMJSUtils.h"
 #include "nsIScriptError.h"
 #include "nsISupportsImpl.h"
+#include "mozilla/dom/FetchPriority.h"
 #include "mozilla/dom/HTMLScriptElement.h"
 #include "mozilla/dom/HTMLScriptElementBinding.h"
 #include "mozilla/StaticPrefs_dom.h"
@@ -58,6 +60,19 @@ nsresult HTMLScriptElement::BindToTree(BindContext& aContext,
   return NS_OK;
 }
 
+namespace {
+// <https://html.spec.whatwg.org/multipage/urls-and-fetching.html#fetch-priority-attributes>.
+static const nsAttrValue::EnumTable kFetchPriorityEnumTable[] = {
+    {kFetchPriorityAttributeValueHigh, FetchPriority::High},
+    {kFetchPriorityAttributeValueLow, FetchPriority::Low},
+    {kFetchPriorityAttributeValueAuto, FetchPriority::Auto},
+    {nullptr, 0}};
+
+// <https://html.spec.whatwg.org/multipage/urls-and-fetching.html#fetch-priority-attributes>.
+static const nsAttrValue::EnumTable*
+    kFetchPriorityEnumTableInvalidValueDefault = &kFetchPriorityEnumTable[2];
+}  // namespace
+
 bool HTMLScriptElement::ParseAttribute(int32_t aNamespaceID, nsAtom* aAttribute,
                                        const nsAString& aValue,
                                        nsIPrincipal* aMaybeScriptedPrincipal,
@@ -72,6 +87,13 @@ bool HTMLScriptElement::ParseAttribute(int32_t aNamespaceID, nsAtom* aAttribute,
       aResult.ParseStringOrAtom(aValue);
       return true;
     }
+
+    if (aAttribute == nsGkAtoms::fetchpriority) {
+      aResult.ParseEnumValue(aValue, kFetchPriorityEnumTable,
+                             false /* aCaseSensitive */,
+                             kFetchPriorityEnumTableInvalidValueDefault);
+      return true;
+    }
   }
 
   return nsGenericHTMLElement::ParseAttribute(aNamespaceID, aAttribute, aValue,
@@ -211,6 +233,12 @@ bool HTMLScriptElement::HasScriptContent() {
          nsContentUtils::HasNonEmptyTextContent(this);
 }
 
+void HTMLScriptElement::GetFetchPriority(nsAString& aFetchPriority) const {
+  // <https://html.spec.whatwg.org/multipage/urls-and-fetching.html#fetch-priority-attributes>.
+  GetEnumAttr(nsGkAtoms::fetchpriority, kFetchPriorityAttributeValueAuto,
+              aFetchPriority);
+}
+
 // https://html.spec.whatwg.org/multipage/scripting.html#dom-script-supports
 /* static */
 bool HTMLScriptElement::Supports(const GlobalObject& aGlobal,

dom/html/HTMLScriptElement.h

@@ -128,12 +128,10 @@ class HTMLScriptElement final : public nsGenericHTMLElement,
     GetEnumAttr(nsGkAtoms::referrerpolicy, "", aReferrerPolicy);
   }
 
-  void GetFetchPriority(nsAString& aFetchPriority) {
-    // TODO: impl.
-  }
+  void GetFetchPriority(nsAString& aFetchPriority) const;
 
   void SetFetchPriority(const nsAString& aFetchPriority) {
-    // TODO: impl.
+    SetHTMLAttr(nsGkAtoms::fetchpriority, aFetchPriority);
   }
 
   [[nodiscard]] static bool Supports(const GlobalObject& aGlobal,

dom/html/moz.build

@@ -43,6 +43,7 @@ EXPORTS.mozilla += [
 EXPORTS.mozilla.dom += [
     "ConstraintValidation.h",
     "ElementInternals.h",
+    "FetchPriority.h",
     "HTMLAllCollection.h",
     "HTMLAnchorElement.h",
     "HTMLAreaElement.h",
@@ -127,6 +128,7 @@ EXPORTS.mozilla.dom += [
 UNIFIED_SOURCES += [
     "ConstraintValidation.cpp",
     "ElementInternals.cpp",
+    "FetchPriority.cpp",
     "HTMLAllCollection.cpp",
     "HTMLAnchorElement.cpp",
     "HTMLAreaElement.cpp",

testing/web-platform/meta/html/scripting/the-script-element/attr-script-fetchpriority.html.ini

@@ -1,6 +0,0 @@
-[attr-script-fetchpriority.html]
-  [fetchpriority attribute on <script> elements should reflect valid IDL values]
-    expected: FAIL
-
-  [default fetchpriority attribute on <script> elements should be 'auto']
-    expected: FAIL