1 files changed, 184 insertions, 0 deletions
diff --git a/dom/script/ScriptElement.cpp b/dom/script/ScriptElement.cpp
new file mode 100644
index 0000000000..d242888ce3
--- /dev/null
+++ b/dom/script/ScriptElement.cpp
@@ -0,0 +1,184 @@
+/* -*- 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 "ScriptElement.h"
+#include "ScriptLoader.h"
+#include "mozilla/BasicEvents.h"
+#include "mozilla/CycleCollectedJSContext.h"
+#include "mozilla/EventDispatcher.h"
+#include "mozilla/dom/Document.h"
+#include "mozilla/dom/Element.h"
+#include "mozilla/dom/MutationEventBinding.h"
+#include "nsContentUtils.h"
+#include "nsThreadUtils.h"
+#include "nsPresContext.h"
+#include "nsIParser.h"
+#include "nsGkAtoms.h"
+#include "nsContentSink.h"
+
+using namespace mozilla;
+using namespace mozilla::dom;
+
+NS_IMETHODIMP
+ScriptElement::ScriptAvailable(nsresult aResult, nsIScriptElement* aElement,
+                               bool aIsInlineClassicScript, nsIURI* aURI,
+                               uint32_t aLineNo) {
+  if (!aIsInlineClassicScript && NS_FAILED(aResult)) {
+    nsCOMPtr<nsIParser> parser = do_QueryReferent(mCreatorParser);
+    if (parser) {
+      parser->IncrementScriptNestingLevel();
+    }
+    nsresult rv = FireErrorEvent();
+    if (parser) {
+      parser->DecrementScriptNestingLevel();
+    }
+    return rv;
+  }
+  return NS_OK;
+}
+
+/* virtual */
+nsresult ScriptElement::FireErrorEvent() {
+  nsIContent* cont = GetAsContent();
+
+  return nsContentUtils::DispatchTrustedEvent(
+      cont->OwnerDoc(), cont, u"error"_ns, CanBubble::eNo, Cancelable::eNo);
+}
+
+NS_IMETHODIMP
+ScriptElement::ScriptEvaluated(nsresult aResult, nsIScriptElement* aElement,
+                               bool aIsInline) {
+  nsresult rv = NS_OK;
+  if (!aIsInline) {
+    nsCOMPtr<nsIContent> cont = GetAsContent();
+
+    RefPtr<nsPresContext> presContext =
+        nsContentUtils::GetContextForContent(cont);
+
+    nsEventStatus status = nsEventStatus_eIgnore;
+    EventMessage message = NS_SUCCEEDED(aResult) ? eLoad : eLoadError;
+    WidgetEvent event(true, message);
+    // Load event doesn't bubble.
+    event.mFlags.mBubbles = (message != eLoad);
+
+    EventDispatcher::Dispatch(cont, presContext, &event, nullptr, &status);
+  }
+
+  return rv;
+}
+
+void ScriptElement::CharacterDataChanged(nsIContent* aContent,
+                                         const CharacterDataChangeInfo&) {
+  MaybeProcessScript();
+}
+
+void ScriptElement::AttributeChanged(Element* aElement, int32_t aNameSpaceID,
+                                     nsAtom* aAttribute, int32_t aModType,
+                                     const nsAttrValue* aOldValue) {
+  // https://html.spec.whatwg.org/#script-processing-model
+  // When a script element el that is not parser-inserted experiences one of the
+  // events listed in the following list, the user agent must immediately
+  // prepare the script element el:
+  //  - The script element is connected and has a src attribute set where
+  //  previously the element had no such attribute.
+  if (aElement->IsSVGElement() && ((aNameSpaceID != kNameSpaceID_XLink &&
+                                    aNameSpaceID != kNameSpaceID_None) ||
+                                   aAttribute != nsGkAtoms::href)) {
+    return;
+  }
+  if (aElement->IsHTMLElement() &&
+      (aNameSpaceID != kNameSpaceID_None || aAttribute != nsGkAtoms::src)) {
+    return;
+  }
+  if (mParserCreated == NOT_FROM_PARSER &&
+      aModType == MutationEvent_Binding::ADDITION) {
+    auto* cont = GetAsContent();
+    if (cont->IsInComposedDoc()) {
+      MaybeProcessScript();
+    }
+  }
+}
+
+void ScriptElement::ContentAppended(nsIContent* aFirstNewContent) {
+  MaybeProcessScript();
+}
+
+void ScriptElement::ContentInserted(nsIContent* aChild) {
+  MaybeProcessScript();
+}
+
+bool ScriptElement::MaybeProcessScript() {
+  nsIContent* cont = GetAsContent();
+
+  NS_ASSERTION(cont->DebugGetSlots()->mMutationObservers.contains(this),
+               "You forgot to add self as observer");
+
+  // https://html.spec.whatwg.org/#parsing-main-incdata
+  // An end tag whose tag name is "script"
+  //  - If the active speculative HTML parser is null and the JavaScript
+  // execution context stack is empty, then perform a microtask checkpoint.
+  nsContentUtils::AddScriptRunner(NS_NewRunnableFunction(
+      "ScriptElement::MaybeProcessScript", []() { nsAutoMicroTask mt; }));
+
+  if (mAlreadyStarted || !mDoneAddingChildren || !cont->GetComposedDoc() ||
+      mMalformed) {
+    return false;
+  }
+
+  if (!HasScriptContent()) {
+    // In the case of an empty, non-external classic script, there is nothing
+    // to process. However, we must perform a microtask checkpoint afterwards,
+    // as per https://html.spec.whatwg.org/#clean-up-after-running-script
+    if (mKind == JS::loader::ScriptKind::eClassic && !mExternal) {
+      nsContentUtils::AddScriptRunner(NS_NewRunnableFunction(
+          "ScriptElement::MaybeProcessScript", []() { nsAutoMicroTask mt; }));
+    }
+    return false;
+  }
+
+  // Check the type attribute to determine language and version. If type exists,
+  // it trumps the deprecated 'language='.
+  nsAutoString type;
+  bool hasType = GetScriptType(type);
+  if (!type.IsEmpty()) {
+    NS_ENSURE_TRUE(nsContentUtils::IsJavascriptMIMEType(type) ||
+                       type.LowerCaseEqualsASCII("module") ||
+                       type.LowerCaseEqualsASCII("importmap"),
+                   false);
+  } else if (!hasType) {
+    // "language" is a deprecated attribute of HTML, so we check it only for
+    // HTML script elements.
+    if (cont->IsHTMLElement()) {
+      nsAutoString language;
+      cont->AsElement()->GetAttr(kNameSpaceID_None, nsGkAtoms::language,
+                                 language);
+      if (!language.IsEmpty() &&
+          !nsContentUtils::IsJavaScriptLanguage(language)) {
+        return false;
+      }
+    }
+  }
+
+  Document* ownerDoc = cont->OwnerDoc();
+  FreezeExecutionAttrs(ownerDoc);
+
+  mAlreadyStarted = true;
+
+  nsCOMPtr<nsIParser> parser = ((nsIScriptElement*)this)->GetCreatorParser();
+  if (parser) {
+    nsCOMPtr<nsIContentSink> sink = parser->GetContentSink();
+    if (sink) {
+      nsCOMPtr<Document> parserDoc = do_QueryInterface(sink->GetTarget());
+      if (ownerDoc != parserDoc) {
+        // Willful violation of HTML5 as of 2010-12-01
+        return false;
+      }
+    }
+  }
+
+  RefPtr<ScriptLoader> loader = ownerDoc->ScriptLoader();
+  return loader->ProcessScriptElement(this, type);
+}