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

third_party/WebKit/Source/core/dom/Modulator.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 "core/dom/Modulator.h"
 
 #include "bindings/core/v8/ScriptState.h"
+#include "bindings/core/v8/V8PerContextData.h"
+#include "core/dom/Document.h"
+#include "core/dom/ModulatorImpl.h"
+#include "core/frame/LocalFrame.h"
 
 namespace blink {
 
+Modulator::~Modulator() {}
+
 Modulator* Modulator::from(LocalFrame* frame) {
   ScriptState* scriptState = ScriptState::forMainWorld(frame);
   if (!scriptState)
     return nullptr;
-  // TODO(kouhei): setModulator in V8PerContextData when we land ModulatorImpl.
-  return scriptState->perContextData()->modulator();
+  Modulator* modulator = scriptState->perContextData()->modulator();
+  if (!modulator) {
+    if (Document* document = frame->document()) {
+      ScriptState* scriptState = ScriptState::forMainWorld(frame);
+      modulator = ModulatorImpl::create(scriptState, *document);
+      scriptState->perContextData()->setModulator(modulator);
+    }
+  }
+  return modulator;
 }
 
-KURL Modulator::resolveModuleSpecifier(const String& moduleRequest,
+KURL Modulator::resolveModuleSpecifier(const String& moduleRequest0,
                                        const KURL& baseURL) {
+  String moduleRequest = moduleRequest0.isolatedCopy();
+  if (!moduleRequest.endsWith(".js") && !moduleRequest.endsWith(".glsl")) {
+    moduleRequest.append('.');
+    moduleRequest.append('j');
+    moduleRequest.append('s');
+  }
+  if (moduleRequest.endsWith(".glsl")) {
+    moduleRequest =
+        KURL(KURL(), "data:text/javascript, export default 'glslsrc';");
+  }
   // Step 1. Apply the URL parser to specifier. If the result is not failure,
   // return the result.
   KURL url(KURL(), moduleRequest);
   if (url.isValid())
     return url;
 
   // Step 2. If specifier does not start with the character U+002F SOLIDUS (/),
   // the two-character sequence U+002E FULL STOP, U+002F SOLIDUS (./), or the
   // three-character sequence U+002E FULL STOP, U+002E FULL STOP, U+002F SOLIDUS
   // (../), return failure and abort these steps.
   if (!moduleRequest.startsWith("/") && !moduleRequest.startsWith("./") &&
       !moduleRequest.startsWith("../"))
     return KURL();
 
   // Step 3. Return the result of applying the URL parser to specifier with
   // script's base URL as the base URL.
   DCHECK(baseURL.isValid());
   KURL absoluteURL(baseURL, moduleRequest);
   if (absoluteURL.isValid())
     return absoluteURL;
 
   return KURL();
 }
 
 }  // namespace blink