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// Copyright 2008 Google Inc.
// All Rights Reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
// Author: vladl@google.com (Vlad Losev)
// This sample shows how to test code relying on some global flag variables.
// Combine() helps with generating all possible combinations of such flags,
// and each test is given one combination as a parameter.
// Use class definitions to test from this header.
#include "prime_tables.h"
#include "gtest/gtest.h"
#if GTEST_HAS_COMBINE
// Suppose we want to introduce a new, improved implementation of PrimeTable
// which combines speed of PrecalcPrimeTable and versatility of
// OnTheFlyPrimeTable (see prime_tables.h). Inside it instantiates both
// PrecalcPrimeTable and OnTheFlyPrimeTable and uses the one that is more
// appropriate under the circumstances. But in low memory conditions, it can be
// told to instantiate without PrecalcPrimeTable instance at all and use only
// OnTheFlyPrimeTable.
class HybridPrimeTable : public PrimeTable {
public:
HybridPrimeTable(bool force_on_the_fly, int max_precalculated)
: on_the_fly_impl_(new OnTheFlyPrimeTable),
precalc_impl_(force_on_the_fly ? NULL :
new PreCalculatedPrimeTable(max_precalculated)),
max_precalculated_(max_precalculated) {}
virtual ~HybridPrimeTable() {
delete on_the_fly_impl_;
delete precalc_impl_;
}
virtual bool IsPrime(int n) const {
if (precalc_impl_ != NULL && n < max_precalculated_)
return precalc_impl_->IsPrime(n);
else
return on_the_fly_impl_->IsPrime(n);
}
virtual int GetNextPrime(int p) const {
int next_prime = -1;
if (precalc_impl_ != NULL && p < max_precalculated_)
next_prime = precalc_impl_->GetNextPrime(p);
return next_prime != -1 ? next_prime : on_the_fly_impl_->GetNextPrime(p);
}
private:
OnTheFlyPrimeTable* on_the_fly_impl_;
PreCalculatedPrimeTable* precalc_impl_;
int max_precalculated_;
};
using ::testing::TestWithParam;
using ::testing::Bool;
using ::testing::Values;
using ::testing::Combine;
// To test all code paths for HybridPrimeTable we must test it with numbers
// both within and outside PreCalculatedPrimeTable's capacity and also with
// PreCalculatedPrimeTable disabled. We do this by defining fixture which will
// accept different combinations of parameters for instantiating a
// HybridPrimeTable instance.
class PrimeTableTest : public TestWithParam< ::std::tr1::tuple<bool, int> > {
protected:
virtual void SetUp() {
// This can be written as
//
// bool force_on_the_fly;
// int max_precalculated;
// tie(force_on_the_fly, max_precalculated) = GetParam();
//
// once the Google C++ Style Guide allows use of ::std::tr1::tie.
//
bool force_on_the_fly = ::std::tr1::get<0>(GetParam());
int max_precalculated = ::std::tr1::get<1>(GetParam());
table_ = new HybridPrimeTable(force_on_the_fly, max_precalculated);
}
virtual void TearDown() {
delete table_;
table_ = NULL;
}
HybridPrimeTable* table_;
};
TEST_P(PrimeTableTest, ReturnsFalseForNonPrimes) {
// Inside the test body, you can refer to the test parameter by GetParam().
// In this case, the test parameter is a PrimeTable interface pointer which
// we can use directly.
// Please note that you can also save it in the fixture's SetUp() method
// or constructor and use saved copy in the tests.
EXPECT_FALSE(table_->IsPrime(-5));
EXPECT_FALSE(table_->IsPrime(0));
EXPECT_FALSE(table_->IsPrime(1));
EXPECT_FALSE(table_->IsPrime(4));
EXPECT_FALSE(table_->IsPrime(6));
EXPECT_FALSE(table_->IsPrime(100));
}
TEST_P(PrimeTableTest, ReturnsTrueForPrimes) {
EXPECT_TRUE(table_->IsPrime(2));
EXPECT_TRUE(table_->IsPrime(3));
EXPECT_TRUE(table_->IsPrime(5));
EXPECT_TRUE(table_->IsPrime(7));
EXPECT_TRUE(table_->IsPrime(11));
EXPECT_TRUE(table_->IsPrime(131));
}
TEST_P(PrimeTableTest, CanGetNextPrime) {
EXPECT_EQ(2, table_->GetNextPrime(0));
EXPECT_EQ(3, table_->GetNextPrime(2));
EXPECT_EQ(5, table_->GetNextPrime(3));
EXPECT_EQ(7, table_->GetNextPrime(5));
EXPECT_EQ(11, table_->GetNextPrime(7));
EXPECT_EQ(131, table_->GetNextPrime(128));
}
// In order to run value-parameterized tests, you need to instantiate them,
// or bind them to a list of values which will be used as test parameters.
// You can instantiate them in a different translation module, or even
// instantiate them several times.
//
// Here, we instantiate our tests with a list of parameters. We must combine
// all variations of the boolean flag suppressing PrecalcPrimeTable and some
// meaningful values for tests. We choose a small value (1), and a value that
// will put some of the tested numbers beyond the capability of the
// PrecalcPrimeTable instance and some inside it (10). Combine will produce all
// possible combinations.
INSTANTIATE_TEST_CASE_P(MeaningfulTestParameters,
PrimeTableTest,
Combine(Bool(), Values(1, 10)));
#else
// Google Test may not support Combine() with some compilers. If we
// use conditional compilation to compile out all code referring to
// the gtest_main library, MSVC linker will not link that library at
// all and consequently complain about missing entry point defined in
// that library (fatal error LNK1561: entry point must be
// defined). This dummy test keeps gtest_main linked in.
TEST(DummyTest, CombineIsNotSupportedOnThisPlatform) {}
#endif // GTEST_HAS_COMBINE
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