Add methods for creating V8 extras-based ReadableStreams from C++

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

 // 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 "bindings/core/v8/ReadableStreamOperations.h"
 
 #include "bindings/core/v8/ExceptionState.h"
 #include "bindings/core/v8/ScriptFunction.h"
 #include "bindings/core/v8/ScriptState.h"
 #include "bindings/core/v8/ScriptValue.h"
 #include "bindings/core/v8/V8Binding.h"
 #include "bindings/core/v8/V8BindingForTesting.h"
 #include "bindings/core/v8/V8BindingMacros.h"
 #include "bindings/core/v8/V8IteratorResultValue.h"
 #include "bindings/core/v8/V8ThrowException.h"
 #include "core/dom/Document.h"
+#include "core/streams/ReadableStreamController.h"
+#include "core/streams/UnderlyingSourceBase.h"
 #include "platform/heap/Handle.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include <v8.h>
 
 namespace blink {
 
 namespace {
 
 class NotReached : public ScriptFunction {
 public:
@@ skipping 76 matching lines @@
 
     ScriptValue call(ScriptValue value) override
     {
         m_iteration->set(value);
         return value;
     }
 
     Member<Iteration> m_iteration;
 };
 
+class TestUnderlyingSource final : public UnderlyingSourceBase {
+public:
+    explicit TestUnderlyingSource(ScriptState* scriptState)
+        : UnderlyingSourceBase(scriptState)
+    {
+    }
+
+    // Just expose the controller methods for easy testing
+    void enqueue(ScriptValue value) { controller()->enqueue(value); }
+    void close() { controller()->close(); }
+    void error(ScriptValue value) { controller()->error(value); }
+    double desiredSize() { return controller()->desiredSize(); }
+};
+
 class ReadableStreamOperationsTest : public ::testing::Test {
 public:
     ReadableStreamOperationsTest()
         : m_scope(v8::Isolate::GetCurrent())
         , m_block(isolate())
         , m_document(Document::create())
     {
         scriptState()->setExecutionContext(m_document.get());
     }
     ~ReadableStreamOperationsTest() override
@@ skipping 130 matching lines @@
     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());
 }
 
+TEST_F(ReadableStreamOperationsTest, CreateReadableStreamWithCustomUnderlyingSourceAndStrategy)
+{
+    auto underlyingSource = new TestUnderlyingSource(scriptState());
+
+    ScriptValue strategy = ReadableStreamOperations::createCountQueuingStrategy(scriptState(), 10);
+    ASSERT_FALSE(strategy.isEmpty());
+
+    ScriptValue stream = ReadableStreamOperations::createReadableStream(scriptState(), underlyingSource, strategy);
+    ASSERT_FALSE(stream.isEmpty());
+
+    EXPECT_EQ(10, underlyingSource->desiredSize());
+
+    underlyingSource->enqueue(ScriptValue::from(scriptState(), "a"));
+    EXPECT_EQ(9, underlyingSource->desiredSize());
+
+    underlyingSource->enqueue(ScriptValue::from(scriptState(), "b"));
+    EXPECT_EQ(8, underlyingSource->desiredSize());
+
+    ScriptValue reader;
+    {
+        TrackExceptionState es;
+        reader = ReadableStreamOperations::getReader(scriptState(), stream, es);
+        ASSERT_FALSE(es.hadException());
+    }
+    ASSERT_FALSE(reader.isEmpty());
+
+    Iteration* it1 = new Iteration();
+    Iteration* it2 = new Iteration();
+    Iteration* it3 = new Iteration();
+    ReadableStreamOperations::read(scriptState(), reader).then(Function::createFunction(scriptState(), it1), NotReached::createFunction(scriptState()));
+    ReadableStreamOperations::read(scriptState(), reader).then(Function::createFunction(scriptState(), it2), NotReached::createFunction(scriptState()));
+    ReadableStreamOperations::read(scriptState(), reader).then(Function::createFunction(scriptState(), it3), NotReached::createFunction(scriptState()));
+
+    isolate()->RunMicrotasks();
+
+    EXPECT_EQ(10, underlyingSource->desiredSize());
+
+    EXPECT_TRUE(it1->isSet());
+    EXPECT_TRUE(it1->isValid());
+    EXPECT_FALSE(it1->isDone());
+    EXPECT_EQ("a", it1->value());
+
+    EXPECT_TRUE(it2->isSet());
+    EXPECT_TRUE(it2->isValid());
+    EXPECT_FALSE(it2->isDone());
+    EXPECT_EQ("b", it2->value());
+
+    EXPECT_FALSE(it3->isSet());
+
+    underlyingSource->close();
+    isolate()->RunMicrotasks();
+
+    EXPECT_TRUE(it3->isSet());
+    EXPECT_TRUE(it3->isValid());
+    EXPECT_TRUE(it3->isDone());
+}
+
 } // namespace
 
 } // namespace blink