Add a utility class to call stream methods implemented with v8 extras.

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

Index: third_party/WebKit/Source/bindings/core/v8/ReadableStreamOperationsTest.cpp
diff --git a/third_party/WebKit/Source/bindings/core/v8/ReadableStreamOperationsTest.cpp b/third_party/WebKit/Source/bindings/core/v8/ReadableStreamOperationsTest.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..e489d64202661ac22916cd8c42bbfe7df2eb4724
--- /dev/null
+++ b/third_party/WebKit/Source/bindings/core/v8/ReadableStreamOperationsTest.cpp
@@ -0,0 +1,307 @@
+// Copyright 2015 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 "config.h"
+#include "bindings/core/v8/ReadableStreamOperations.h"
+
+#include "bindings/core/v8/ScriptFunction.h"
+#include "bindings/core/v8/ScriptState.h"
+#include "bindings/core/v8/V8Binding.h"
+#include "core/testing/DummyPageHolder.h"
+#include "platform/heap/Handle.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include <v8.h>
+
+namespace blink {
+
+namespace {
+
+class NotReached : public ScriptFunction {
+public:
+    static v8::Local<v8::Function> createFunction(ScriptState* scriptState)
+    {
+        NotReached* self = new NotReached(scriptState);
+        return self->bindToV8Function();
+    }
+
+private:
+    explicit NotReached(ScriptState* scriptState)
+        : ScriptFunction(scriptState)
+    {
+    }
+
+    ScriptValue call(ScriptValue) override;
+};
+
+ScriptValue NotReached::call(ScriptValue)
+{
+    EXPECT_TRUE(false) << "'Unreachable' code was reached";
+    return ScriptValue();
+}
+
+class Iteration final : public GarbageCollectedFinalized<Iteration> {
+public:
+    Iteration()
+        : m_isSet(false)
+        , m_isDone(false)
+        , m_isValid(true) {}
+
+    void set(ScriptValue v)
+    {
+        m_isSet = true;
+        if (v.isEmpty() || !v.v8Value()->IsObject()) {
+            m_isValid = false;
+            return;
+        }
+        v8::Local<v8::Object> object = v.v8Value().As<v8::Object>();
+        v8::Local<v8::Value> done;
+        if (!object->Get(v.scriptState()->context(), v8String(v.isolate(), "done")).ToLocal(&done)
+            || done->IsUndefined()) {
+            m_isValid = false;
+            return;
+        }
+        m_isDone = done->ToBoolean()->Value();
+
+        v8::Local<v8::Value> value;
+        if (!object->Get(v.scriptState()->context(), v8String(v.isolate(), "value")).ToLocal(&value)) {
+            m_isValid = false;
+            return;
+        }
+        m_value = toCoreString(value->ToString());
+    }
+
+    bool isSet() const { return m_isSet; }
+    bool isDone() const { return m_isDone; }
+    bool isValid() const { return m_isValid; }
+    const String& value() const { return m_value; }
+
+    DEFINE_INLINE_TRACE() {}
+
+private:
+    bool m_isSet;
+    bool m_isDone;
+    bool m_isValid;
+    String m_value;
+};
+
+class Function : public ScriptFunction {
+public:
+    static v8::Local<v8::Function> createFunction(ScriptState* scriptState, Iteration* iteration)
+    {
+        Function* self = new Function(scriptState, iteration);
+        return self->bindToV8Function();
+    }
+
+    DEFINE_INLINE_VIRTUAL_TRACE()
+    {
+        visitor->trace(m_iteration);
+        ScriptFunction::trace(visitor);
+    }
+
+private:
+    Function(ScriptState* scriptState, Iteration* iteration)
+        : ScriptFunction(scriptState)
+        , m_iteration(iteration)
+    {
+    }
+
+    ScriptValue call(ScriptValue value) override
+    {
+        m_iteration->set(value);
+        return value;
+    }
+
+    Member<Iteration> m_iteration;
+};
+
+class ReadableStreamOperationsTest : public ::testing::Test {
+public:
+    ReadableStreamOperationsTest()
+        : m_pageHolder(DummyPageHolder::create())
+    {
+    }
+
+    ~ReadableStreamOperationsTest() override
+    {
+        ScriptState::Scope scope(scriptState());
+        // Execute all pending microtasks
+        isolate()->RunMicrotasks();
+    }
+
+    OwnPtr<DummyPageHolder> m_pageHolder;
+    ScriptState* scriptState() const { return ScriptState::forMainWorld(&m_pageHolder->frame()); }
+    v8::Isolate* isolate() const { return scriptState()->isolate(); }
+
+    v8::MaybeLocal<v8::Value> eval(const char* s)
+    {
+        v8::MaybeLocal<v8::String> source = v8::String::NewFromUtf8(isolate(), s, v8::String::kNormalString);
+        if (source.IsEmpty()) {
+            ADD_FAILURE();
+            return v8::MaybeLocal<v8::Value>();
+        }
+        v8::MaybeLocal<v8::Script> script = v8::Script::Compile(scriptState()->context(), source.ToLocalChecked());
+        if (script.IsEmpty()) {
+            ADD_FAILURE() << "Compilation fails";
+            return v8::MaybeLocal<v8::Value>();
+        }
+        return script.ToLocalChecked()->Run(scriptState()->context());
+    }
+    v8::MaybeLocal<v8::Value> evalNoThrow(const char* s)
+    {
+        v8::TryCatch block(isolate());
+        v8::MaybeLocal<v8::Value> r = eval(s);
+        if (block.HasCaught())
+            ADD_FAILURE() << toCoreString(block.Exception()->ToString(isolate())).utf8().data();
+        return r;
+    }
+};
+
+TEST_F(ReadableStreamOperationsTest, IsReadableStream)
+{
+    ScriptState::Scope scope(scriptState());
+
+    {
+        v8::TryCatch block(isolate());
+        EXPECT_FALSE(ReadableStreamOperations::isReadableStream(scriptState(), v8::Undefined(isolate())));
+        EXPECT_FALSE(block.HasCaught());
+    }
+    {
+        v8::TryCatch block(isolate());
+        EXPECT_FALSE(ReadableStreamOperations::isReadableStream(scriptState(), v8::Null(isolate())));
+        EXPECT_FALSE(block.HasCaught());
+    }
+    {
+        v8::TryCatch block(isolate());
+        EXPECT_FALSE(ReadableStreamOperations::isReadableStream(scriptState(), v8::Object::New(isolate())));
+        EXPECT_FALSE(block.HasCaught());
+    }
+    {
+        v8::Local<v8::Value> stream;
+        ASSERT_TRUE(evalNoThrow("new ReadableStream()").ToLocal(&stream));
+
+        v8::TryCatch block(isolate());
+        EXPECT_TRUE(ReadableStreamOperations::isReadableStream(scriptState(), stream));
+        EXPECT_FALSE(block.HasCaught());
+    }
+}
+
+TEST_F(ReadableStreamOperationsTest, IsReadableStreamReaderInvalid)
+{
+    ScriptState::Scope scope(scriptState());
+
+    {
+        v8::TryCatch block(isolate());
+        EXPECT_FALSE(ReadableStreamOperations::isReadableStreamReader(scriptState(), v8::Undefined(isolate())));
+        EXPECT_FALSE(block.HasCaught());
+    }
+    {
+        v8::TryCatch block(isolate());
+        EXPECT_FALSE(ReadableStreamOperations::isReadableStreamReader(scriptState(), v8::Null(isolate())));
+        EXPECT_FALSE(block.HasCaught());
+    }
+    {
+        v8::TryCatch block(isolate());
+        EXPECT_FALSE(ReadableStreamOperations::isReadableStreamReader(scriptState(), v8::Object::New(isolate())));
+        EXPECT_FALSE(block.HasCaught());
+    }
+    {
+        v8::Local<v8::Value> stream;
+        ASSERT_TRUE(evalNoThrow("new ReadableStream()").ToLocal(&stream));
+
+        v8::TryCatch block(isolate());
+        EXPECT_FALSE(ReadableStreamOperations::isReadableStreamReader(scriptState(), stream));
+        EXPECT_FALSE(block.HasCaught());
+    }
+}
+
+TEST_F(ReadableStreamOperationsTest, GetReader)
+{
+    ScriptState::Scope scope(scriptState());
+    v8::Local<v8::Value> stream;
+    ASSERT_TRUE(evalNoThrow("new ReadableStream()").ToLocal(&stream));
+
+    {
+        v8::TryCatch block(isolate());
+        EXPECT_FALSE(ReadableStreamOperations::isLocked(scriptState(), stream));
+        ScriptValue reader = ReadableStreamOperations::getReader(scriptState(), stream);
+        EXPECT_TRUE(ReadableStreamOperations::isLocked(scriptState(), stream));
+        ASSERT_FALSE(reader.isEmpty());
+        EXPECT_FALSE(block.HasCaught());
+
+        EXPECT_FALSE(ReadableStreamOperations::isReadableStream(scriptState(), reader.v8Value()));
+        EXPECT_TRUE(ReadableStreamOperations::isReadableStreamReader(scriptState(), reader.v8Value()));
+        EXPECT_FALSE(block.HasCaught());
+    }
+
+    {
+        // Already locked!
+        v8::TryCatch block(isolate());
+        ScriptValue reader = ReadableStreamOperations::getReader(scriptState(), stream);
+        ASSERT_TRUE(reader.isEmpty());
+        EXPECT_TRUE(block.HasCaught());
+    }
+}
+
+TEST_F(ReadableStreamOperationsTest, IsDisturbed)
+{
+    ScriptState::Scope scope(scriptState());
+    v8::Local<v8::Value> stream;
+    ASSERT_TRUE(evalNoThrow("stream = new ReadableStream()").ToLocal(&stream));
+
+    v8::TryCatch block(isolate());
+    EXPECT_FALSE(ReadableStreamOperations::isDisturbed(scriptState(), stream));
+
+    ASSERT_FALSE(evalNoThrow("stream.cancel()").IsEmpty());
+
+    EXPECT_TRUE(ReadableStreamOperations::isDisturbed(scriptState(), stream));
+    EXPECT_FALSE(block.HasCaught());
+}
+
+TEST_F(ReadableStreamOperationsTest, Read)
+{
+    ScriptState::Scope scope(scriptState());
+    v8::Local<v8::Value> reader;
+    ASSERT_TRUE(evalNoThrow(
+        "var controller;"
+        "function start(c) { controller = c; }"
+        "new ReadableStream({start}).getReader()").ToLocal(&reader));
+    ASSERT_TRUE(ReadableStreamOperations::isReadableStreamReader(scriptState(), reader));
+
+    Iteration* it1 = new Iteration();
+    Iteration* it2 = new Iteration();
+    v8::TryCatch block(isolate());
+    ReadableStreamOperations::read(scriptState(), reader).then(

[domenic, 2015/12/02 17:53:03]

This is workable but kind of takes a lot of supporting code. I am OK with it if
you are but would it be possible to create the wrapper so that you could write

ReadableStreamOperations::read<String>(scriptState(), reader,
  [](option<String> value) {
    EXPECT_EQ("hello", *value);
  },
  [](auto err) {
    EXPECT_TRUE(false) << "'Unreachable' code was reached";
  });

?

Feel free to ignore though, this might just be my JavaScript brain saying things
that make less sense in C++ :)

[yhirano, 2015/12/03 11:18:29]

Unfortunately, we cannot use lambda for the purpose. See "Lambda Expressions" in
https://chromium-cpp.appspot.com/. I added a utility function to unpack an
iterator to make it less painful.

+        Function::createFunction(scriptState(), it1),
+        NotReached::createFunction(scriptState()));
+    ReadableStreamOperations::read(scriptState(), reader).then(
+        Function::createFunction(scriptState(), it2),
+        NotReached::createFunction(scriptState()));
+
+    isolate()->RunMicrotasks();
+    EXPECT_FALSE(it1->isSet());
+    EXPECT_FALSE(it2->isSet());
+
+    ASSERT_FALSE(evalNoThrow("controller.enqueue('hello')").IsEmpty());
+    isolate()->RunMicrotasks();
+    EXPECT_TRUE(it1->isSet());
+    EXPECT_TRUE(it1->isValid());
+    EXPECT_FALSE(it1->isDone());
+    EXPECT_EQ("hello", it1->value());
+    EXPECT_FALSE(it2->isSet());
+
+    ASSERT_FALSE(evalNoThrow("controller.close()").IsEmpty());
+    isolate()->RunMicrotasks();
+    EXPECT_TRUE(it1->isSet());
+    EXPECT_TRUE(it1->isValid());
+    EXPECT_FALSE(it1->isDone());
+    EXPECT_EQ("hello", it1->value());
+    EXPECT_TRUE(it2->isSet());
+    EXPECT_TRUE(it2->isValid());
+    EXPECT_TRUE(it2->isDone());
+}
+
+} // namespace
+
+} // namespace blink
+