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// Copyright 2020 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 "base/scoped_observation.h"
#include "base/containers/contains.h"
#include "base/ranges/algorithm.h"
#include "base/test/gtest_util.h"
#include "testing/gtest/include/gtest/gtest.h"
namespace base {
namespace {
class TestSourceObserver {};
class TestSource {
public:
void AddObserver(TestSourceObserver* observer);
void RemoveObserver(TestSourceObserver* observer);
bool HasObserver(TestSourceObserver* observer) const;
size_t num_observers() const { return observers_.size(); }
private:
std::vector<TestSourceObserver*> observers_;
};
void TestSource::AddObserver(TestSourceObserver* observer) {
observers_.push_back(observer);
}
void TestSource::RemoveObserver(TestSourceObserver* observer) {
auto it = base::ranges::find(observers_, observer);
EXPECT_TRUE(it != observers_.end());
observers_.erase(it);
}
bool TestSource::HasObserver(TestSourceObserver* observer) const {
return base::Contains(observers_, observer);
}
using TestScopedObservation = ScopedObservation<TestSource, TestSourceObserver>;
} // namespace
TEST(ScopedObservationTest, RemovesObservationOnDestruction) {
TestSource s1;
{
TestSourceObserver o1;
TestScopedObservation obs(&o1);
EXPECT_EQ(0u, s1.num_observers());
EXPECT_FALSE(s1.HasObserver(&o1));
obs.Observe(&s1);
EXPECT_EQ(1u, s1.num_observers());
EXPECT_TRUE(s1.HasObserver(&o1));
}
// Test that the observation is removed when it goes out of scope.
EXPECT_EQ(0u, s1.num_observers());
}
TEST(ScopedObservationTest, Reset) {
TestSource s1;
TestSourceObserver o1;
TestScopedObservation obs(&o1);
EXPECT_EQ(0u, s1.num_observers());
obs.Reset();
obs.Observe(&s1);
EXPECT_EQ(1u, s1.num_observers());
EXPECT_TRUE(s1.HasObserver(&o1));
obs.Reset();
EXPECT_EQ(0u, s1.num_observers());
// Safe to call with no observation.
obs.Reset();
EXPECT_EQ(0u, s1.num_observers());
}
TEST(ScopedObservationTest, IsObserving) {
TestSource s1;
TestSourceObserver o1;
TestScopedObservation obs(&o1);
EXPECT_FALSE(obs.IsObserving());
obs.Observe(&s1);
EXPECT_TRUE(obs.IsObserving());
obs.Reset();
EXPECT_FALSE(obs.IsObserving());
}
TEST(ScopedObservationTest, IsObservingSource) {
TestSource s1;
TestSource s2;
TestSourceObserver o1;
TestScopedObservation obs(&o1);
EXPECT_FALSE(obs.IsObservingSource(&s1));
EXPECT_FALSE(obs.IsObservingSource(&s2));
obs.Observe(&s1);
EXPECT_TRUE(obs.IsObservingSource(&s1));
EXPECT_FALSE(obs.IsObservingSource(&s2));
obs.Reset();
EXPECT_FALSE(obs.IsObservingSource(&s1));
EXPECT_FALSE(obs.IsObservingSource(&s2));
}
namespace {
// A test source with oddly named Add/Remove functions.
class TestSourceWithNonDefaultNames {
public:
void AddFoo(TestSourceObserver* observer) { impl_.AddObserver(observer); }
void RemoveFoo(TestSourceObserver* observer) {
impl_.RemoveObserver(observer);
}
const TestSource& impl() const { return impl_; }
private:
TestSource impl_;
};
using TestScopedObservationWithNonDefaultNames =
ScopedObservation<TestSourceWithNonDefaultNames,
TestSourceObserver,
&TestSourceWithNonDefaultNames::AddFoo,
&TestSourceWithNonDefaultNames::RemoveFoo>;
} // namespace
TEST(ScopedObservationTest, NonDefaultNames) {
TestSourceWithNonDefaultNames s1;
TestSourceObserver o1;
EXPECT_EQ(0u, s1.impl().num_observers());
{
TestScopedObservationWithNonDefaultNames obs(&o1);
obs.Observe(&s1);
EXPECT_EQ(1u, s1.impl().num_observers());
EXPECT_TRUE(s1.impl().HasObserver(&o1));
}
}
} // namespace base
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