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

third_party/WebKit/Source/bindings/core/v8/ScriptModule.cpp

 // Copyright 2017 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "bindings/core/v8/ScriptModule.h"
 
 #include "bindings/core/v8/V8Binding.h"
+#include "bindings/core/v8/V8PerContextData.h"
+#include "core/dom/DOMException.h"
+#include "core/dom/ExceptionCode.h"
+#include "core/dom/Modulator.h"
+#include "core/dom/ScriptModuleResolver.h"
 
 namespace blink {
 
 ScriptModule::ScriptModule(v8::Isolate* isolate, v8::Local<v8::Module> module)
-    : m_module(SharedPersistent<v8::Module>::create(module, isolate)) {}
+    : m_module(SharedPersistent<v8::Module>::create(module, isolate)),
+      m_identityHash(static_cast<unsigned>(module->GetIdentityHash())) {}
 
 ScriptModule::~ScriptModule() {}
 
 ScriptModule ScriptModule::compile(v8::Isolate* isolate,
                                    const String& source,
                                    const String& fileName) {
   v8::TryCatch tryCatch(isolate);
   tryCatch.SetVerbose(true);
   v8::Local<v8::Module> module;
   if (!v8Call(V8ScriptRunner::compileModule(isolate, source, fileName), module,
               tryCatch)) {
-    // TODO(adamk): Signal failure somehow.
-    return ScriptModule(isolate, module);
+    return ScriptModule();
   }
   return ScriptModule(isolate, module);
 }
 
-v8::MaybeLocal<v8::Module> dummyCallback(v8::Local<v8::Context> context,
-                                         v8::Local<v8::String> specifier,
-                                         v8::Local<v8::Module> referrer) {
-  return v8::MaybeLocal<v8::Module>();
+v8::MaybeLocal<v8::Module> ScriptModule::resolveModuleCallback(
+    v8::Local<v8::Context> context,
+    v8::Local<v8::String> specifier,
+    v8::Local<v8::Module> referrer) {
+  v8::Isolate* isolate = context->GetIsolate();
+  Modulator* modulator = V8PerContextData::from(context)->modulator();
+  DCHECK(modulator);
+
+  ScriptModule referrerRecord(isolate, referrer);
+  ExceptionState exceptionState(isolate, ExceptionState::ExecutionContext,
+                                "ScriptModule", "resolveModuleCallback");
+  ScriptModule resolved = modulator->scriptModuleResolver()->resolve(
+      toCoreStringWithNullCheck(specifier), referrerRecord,
+      exceptionState);
+  if (resolved.isNull()) {
+    DCHECK(exceptionState.hadException());
+    return v8::MaybeLocal<v8::Module>();
+  }
+
+  return v8::MaybeLocal<v8::Module>(resolved.m_module->newLocal(isolate));
 }
 
-bool ScriptModule::instantiate(ScriptState* scriptState) {
+ScriptValue ScriptModule::instantiate(ScriptState* scriptState) {
+  v8::Isolate* isolate = scriptState->isolate();
+  v8::TryCatch tryCatch(isolate);
+
   DCHECK(!isNull());
   v8::Local<v8::Context> context = scriptState->context();
-  // TODO(adamk): pass in a real callback.
-  return m_module->newLocal(scriptState->isolate())
-      ->Instantiate(context, &dummyCallback);
+  bool success = m_module->newLocal(scriptState->isolate())
+                     ->Instantiate(context, &resolveModuleCallback);
+  if (!success) {
+    DCHECK(tryCatch.HasCaught());
+    return ScriptValue(scriptState, tryCatch.Exception());
+  }
+  // DCHECK(!tryCatch.HasCaught());
+  return ScriptValue();
 }
 
 void ScriptModule::evaluate(ScriptState* scriptState) {
   v8::Isolate* isolate = scriptState->isolate();
   v8::TryCatch tryCatch(isolate);
   tryCatch.SetVerbose(true);
   v8::Local<v8::Value> result;
   if (!v8Call(V8ScriptRunner::evaluateModule(m_module->newLocal(isolate),
                                              scriptState->context(), isolate),
               result, tryCatch)) {
     // TODO(adamk): report error
   }
 }
 
+Vector<String> ScriptModule::moduleRequests(ScriptState* scriptState) {
+  if (isNull())
+    return Vector<String>();
+
+  v8::Local<v8::Module> module = m_module->newLocal(scriptState->isolate());
+
+  Vector<String> ret;
+
+  int length = module->GetModuleRequestsLength();
+  ret.reserveInitialCapacity(length);
+  for (int i = 0; i < length; ++i) {
+    v8::Local<v8::String> v8Name = module->GetModuleRequest(i);
+    String name = toCoreString(v8Name);
+    ret.push_back(name);
+  }
+  return ret;
+}
+
 }  // namespace blink