Add WTF::makeCancellable

third_party/WebKit/Source/wtf/MakeCancellableTest.cpp

+// Copyright 2016 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 "wtf/MakeCancellable.h"
+
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace WTF {
+namespace {
+
+void add(int* x, int y) { *x += y; }
+
+class DestructionCounter {
+public:
+    explicit DestructionCounter(int* counter) : m_counter(counter) { }
+    ~DestructionCounter()
+    {
+        if (m_counter)
+            ++*m_counter;
+    }
+
+    DestructionCounter(DestructionCounter&& other) : m_counter(other.m_counter)
+    {
+        other.m_counter = nullptr;
+    }
+
+private:
+    int* m_counter;
+};
+
+} // namespace
+
+TEST(MakeCancellableTest, NotCancelled)
+{
+    int v = 0;
+    auto f = bind(&add, unretained(&v));
+    FunctionCanceller canceller;
+    std::tie(f, canceller) = makeCancellable(std::move(f));
+
+    EXPECT_EQ(0, v);
+    (*f)(3);
+    EXPECT_EQ(3, v);
+}
+
+TEST(MakeCancellableTest, ExplicitCancel)
+{
+    int v = 0;
+    auto f = bind(&add, unretained(&v));
+    FunctionCanceller canceller;
+    std::tie(f, canceller) = makeCancellable(std::move(f));
+
+    canceller.cancel();
+    EXPECT_EQ(0, v);
+    (*f)(3);
+    EXPECT_EQ(0, v);
+}
+
+TEST(MakeCancellableTest, ScopeOutCancel)
+{
+    int v = 0;
+    auto f = bind(&add, unretained(&v));
+    {
+        FunctionCanceller canceller;
+        std::tie(f, canceller) = makeCancellable(std::move(f));
+    }
+
+    EXPECT_EQ(0, v);
+    (*f)(3);
+    EXPECT_EQ(0, v);
+}
+
+TEST(MakeCancellableTest, Detach)
+{
+    int v = 0;
+    auto f = bind(&add, unretained(&v));
+    {
+        FunctionCanceller canceller;
+        std::tie(f, canceller) = makeCancellable(std::move(f));
+        canceller.detach();
+    }
+
+    EXPECT_EQ(0, v);
+    (*f)(3);
+    EXPECT_EQ(3, v);
+}
+
+TEST(MakeCancellableTest, CancellerMove)
+{
+    int v = 0;
+    auto f = bind(&add, unretained(&v));
+    FunctionCanceller canceller;
+    std::tie(f, canceller) = makeCancellable(std::move(f));
+
+    FunctionCanceller moved = std::move(canceller);
+
+    canceller.cancel(); // This should take no effect.
+
+    EXPECT_EQ(0, v);
+    (*f)(3);
+    EXPECT_EQ(3, v);
+
+    std::tie(f, canceller) = makeCancellable(bind(&add, unretained(&v)));
+    moved = std::move(canceller);
+    moved.cancel();
+
+    EXPECT_EQ(3, v);
+    (*f)(4);
+    EXPECT_EQ(3, v);
+}
+
+TEST(MakeCancellableTest, MultiCall)
+{
+    int v = 0;
+    auto f = bind(&add, unretained(&v));
+    FunctionCanceller canceller;
+    std::tie(f, canceller) = makeCancellable(std::move(f));
+
+    EXPECT_EQ(0, v);
+    (*f)(2);
+    EXPECT_EQ(2, v);
+    (*f)(3);
+    EXPECT_EQ(5, v);
+}
+
+TEST(MakeCancellableTest, DestroyOnCancel)
+{
+    int counter = 0;
+    auto f = bind([](const DestructionCounter&) {}, DestructionCounter(&counter));
+    FunctionCanceller canceller;
+    std::tie(f, canceller) = makeCancellable(std::move(f));
+
+    EXPECT_EQ(0, counter);
+    canceller.cancel();
+    EXPECT_EQ(1, counter);
+}
+
+} // namespace WTF