[WIP Prototype] ES6 https://html.spec.whatwg.org/#fetch-a-single-module-script implementation

third_party/WebKit/Source/core/dom/ScriptLoader.cpp

Index: third_party/WebKit/Source/core/dom/ScriptLoader.cpp
diff --git a/third_party/WebKit/Source/core/dom/ScriptLoader.cpp b/third_party/WebKit/Source/core/dom/ScriptLoader.cpp
index f85f7ca523bfd0215bbf113a5eea03f0935ae9b5..35377b8b84234fc8425fd6e7b410dde98c0f5f26 100644
--- a/third_party/WebKit/Source/core/dom/ScriptLoader.cpp
+++ b/third_party/WebKit/Source/core/dom/ScriptLoader.cpp
@@ -26,11 +26,14 @@
 
 #include "bindings/core/v8/ScriptController.h"
 #include "bindings/core/v8/ScriptSourceCode.h"
+#include "bindings/core/v8/ScriptState.h"
 #include "core/HTMLNames.h"
 #include "core/SVGNames.h"
 #include "core/dom/Document.h"
 #include "core/dom/DocumentParserTiming.h"
 #include "core/dom/IgnoreDestructiveWriteCountIncrementer.h"
+#include "core/dom/Modulator.h"
+#include "core/dom/ModuleScript.h"
 #include "core/dom/ScriptLoaderClient.h"
 #include "core/dom/ScriptRunner.h"
 #include "core/dom/ScriptableDocumentParser.h"
@@ -45,6 +48,7 @@
 #include "core/html/imports/HTMLImport.h"
 #include "core/html/parser/HTMLParserIdioms.h"
 #include "core/inspector/ConsoleMessage.h"
+#include "core/loader/modulescript/ModuleScriptFetchRequest.h"
 #include "core/svg/SVGScriptElement.h"
 #include "platform/WebFrameScheduler.h"
 #include "platform/loader/fetch/AccessControlStatus.h"
@@ -60,6 +64,48 @@
 
 namespace blink {
 
+class ScriptElementModuleClient
+    : public GarbageCollectedFinalized<ScriptElementModuleClient>,
+      public ModuleTreeClient {
+  USING_GARBAGE_COLLECTED_MIXIN(ScriptElementModuleClient);
+
+ public:
+  static ScriptElementModuleClient* create(Element* element) {
+    return new ScriptElementModuleClient(element);
+  }
+  virtual ~ScriptElementModuleClient() = default;
+
+  DECLARE_TRACE();
+
+ private:
+  ScriptElementModuleClient(Element* element) : m_element(element) {}
+
+  // Implements ModuleTreeClient
+  void notifyModuleTreeLoadFinished(ModuleScript*) override;
+
+  Member<Element> m_element;
+};
+
+void ScriptElementModuleClient::notifyModuleTreeLoadFinished(
+    ModuleScript* moduleScript) {
+  printf("notifyFinishedModuleTree!!! moduleScript: %p\n", moduleScript);
+  if (!moduleScript)
+    return;
+  DCHECK_EQ(moduleScript->instantiationState(),
+            ModuleInstantiationState::Instantiated);
+
+  LocalFrame* frame = m_element->document().frame();
+
+  // TODO(kouhei): Actually we should just return w/ the prepared script here.
+  // In this prototype, we will execute the module immediately just for fun. :)
+  Modulator::from(frame)->executeModule(moduleScript->record());
+}
+
+DEFINE_TRACE(ScriptElementModuleClient) {
+  visitor->trace(m_element);
+  ModuleTreeClient::trace(visitor);
+}
+
 ScriptLoader::ScriptLoader(Element* element,
                            bool parserInserted,
                            bool alreadyStarted,
@@ -107,6 +153,7 @@ ScriptLoader::~ScriptLoader() {}
 DEFINE_TRACE(ScriptLoader) {
   visitor->trace(m_element);
   visitor->trace(m_resource);
+  visitor->trace(m_elementModuleClient);
   visitor->trace(m_pendingScript);
   PendingScriptClient::trace(visitor);
 }
@@ -319,6 +366,7 @@ bool ScriptLoader::prepareScript(const TextPosition& scriptStartPosition,
     if (m_documentWriteIntervention ==
         DocumentWriteIntervention::FetchDocWrittenScriptDeferIdle)
       defer = FetchRequest::IdleLoad;
+
     if (!fetchScript(client->sourceAttributeValue(), encoding, defer))
       return false;
   }
@@ -522,19 +570,52 @@ bool ScriptLoader::fetchScript(const String& sourceUrl,
   DCHECK(!m_resource);
   // 21. "If the element has a src content attribute, run these substeps:"
   if (!stripLeadingAndTrailingHTMLSpaces(sourceUrl).isEmpty()) {
-    // 21.4. "Parse src relative to the element's node document."
-    FetchRequest request(
-        ResourceRequest(elementDocument->completeURL(sourceUrl)),
-        m_element->localName());
+    KURL url = elementDocument->completeURL(sourceUrl);
 
     // 15. "Let CORS setting be the current state of the element's
     //      crossorigin content attribute."
     CrossOriginAttributeValue crossOrigin = crossOriginAttributeValue(
         m_element->fastGetAttribute(HTMLNames::crossoriginAttr));
 
-    // 16. "Let module script credentials mode be determined by switching
-    //      on CORS setting:"
-    // TODO(hiroshige): Implement this step for "module".
+    if (RuntimeEnabledFeatures::moduleScriptsEnabled() &&
+        client()->typeAttributeValue() == "module") {
+      m_elementModuleClient = ScriptElementModuleClient::create(m_element);
+
+      String nonce;
+      if (ContentSecurityPolicy::isNonceableElement(m_element.get())) {
+        nonce = m_element->fastGetAttribute(HTMLNames::nonceAttr);
+      }
+      ParserDisposition parserState =
+          isParserInserted() ? ParserInserted : NotParserInserted;
+
+      // 16. "Let module script credentials mode be determined by switching
+      //      on CORS setting:"
+      WebURLRequest::FetchCredentialsMode credentialsMode;
+      switch (crossOrigin) {
+        case CrossOriginAttributeNotSet:
+          credentialsMode = WebURLRequest::FetchCredentialsModeOmit;
+          break;
+        case CrossOriginAttributeAnonymous:
+          credentialsMode = WebURLRequest::FetchCredentialsModeSameOrigin;
+          break;
+        case CrossOriginAttributeUseCredentials:
+          credentialsMode = WebURLRequest::FetchCredentialsModeInclude;
+          break;
+        default:
+          NOTREACHED();
+      }
+
+      ModuleScriptFetchRequest moduleRequest(url, nonce, parserState,
+                                             credentialsMode);
+      Modulator::from(elementDocument->frame())
+          ->fetchTree(moduleRequest, m_elementModuleClient);
+      return true;
+    }
+
+    // 21.4. "Parse src relative to the element's node document."
+    FetchRequest request(
+        ResourceRequest(elementDocument->completeURL(sourceUrl)),
+        m_element->localName());
 
     // 21.6, "classic": "Fetch a classic script given ... CORS setting
     //                   ... and encoding."