[modules] Expand API to allow linking and use it in d8

test/cctest/test-modules.cc

+// Copyright 2016 the V8 project 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 "src/flags.h"
+
+#include "test/cctest/cctest.h"
+
+using v8::Context;
+using v8::HandleScope;
+using v8::Isolate;
+using v8::Local;
+using v8::MaybeLocal;
+using v8::Module;
+using v8::ScriptCompiler;
+using v8::ScriptOrigin;
+using v8::String;
+using v8::Value;
+
+static MaybeLocal<Module> AlwaysEmptyResolveCallback(Local<Context> context,
+                                                     Local<String> specifier,
+                                                     Local<Module> referrer,
+                                                     Local<Value> data) {
+  return MaybeLocal<Module>();
+}
+
+static int g_count = 0;
+static MaybeLocal<Module> FailOnSecondCallResolveCallback(
+    Local<Context> context, Local<String> specifier, Local<Module> referrer,
+    Local<Value> data) {
+  if (g_count++ > 0) return MaybeLocal<Module>();
+  Local<String> source_text = v8_str("");
+  ScriptOrigin origin(v8_str("module.js"));
+  ScriptCompiler::Source source(source_text, origin);
+  return ScriptCompiler::CompileModule(CcTest::isolate(), &source)
+      .ToLocalChecked();
+}
+
+TEST(ModuleInstantiationFailures) {
+  Isolate* isolate = CcTest::isolate();
+  HandleScope scope(isolate);
+  LocalContext env;
+
+  Local<String> source_text = v8_str(
+      "import './foo.js';"
+      "export {} from './bar.js';");
+  ScriptOrigin origin(v8_str("file.js"));
+  ScriptCompiler::Source source(source_text, origin);
+  Local<Module> module =
+      ScriptCompiler::CompileModule(isolate, &source).ToLocalChecked();
+  CHECK_EQ(2, module->GetModuleRequestsLength());
+  CHECK(v8_str("./foo.js")->StrictEquals(module->GetModuleRequest(0)));
+  CHECK(v8_str("./bar.js")->StrictEquals(module->GetModuleRequest(1)));
+
+  // Instantiation should fail.
+  CHECK(!module->Instantiate(env.local(), AlwaysEmptyResolveCallback));
+
+  // Start over again...
+  module = ScriptCompiler::CompileModule(isolate, &source).ToLocalChecked();
+
+  // Instantiation should fail if a sub-module fails to resolve.
+  g_count = 0;
+  CHECK(!module->Instantiate(env.local(), FailOnSecondCallResolveCallback));
+}
+
+static MaybeLocal<Module> CompileSpecifierAsModuleResolveCallback(
+    Local<Context> context, Local<String> specifier, Local<Module> referrer,
+    Local<Value> data) {
+  ScriptOrigin origin(v8_str("module.js"));
+  ScriptCompiler::Source source(specifier, origin);
+  return ScriptCompiler::CompileModule(CcTest::isolate(), &source)
+      .ToLocalChecked();
+}
+
+TEST(ModuleEvaluation) {
+  Isolate* isolate = CcTest::isolate();
+  HandleScope scope(isolate);
+  LocalContext env;
+
+  Local<String> source_text = v8_str(
+      "import 'Object.expando = 5';"
+      "import 'Object.expando *= 2';");
+  ScriptOrigin origin(v8_str("file.js"));
+  ScriptCompiler::Source source(source_text, origin);
+  Local<Module> module =
+      ScriptCompiler::CompileModule(isolate, &source).ToLocalChecked();
+  CHECK(module->Instantiate(env.local(),
+                            CompileSpecifierAsModuleResolveCallback));
+  CHECK(!module->Evaluate(env.local()).IsEmpty());
+  ExpectInt32("Object.expando", 10);
+}