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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.
// 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"
namespace {
// 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 ? nullptr : new PreCalculatedPrimeTable(max_precalculated)), max_precalculated_(max_precalculated) {} ~HybridPrimeTable() override { delete on_the_fly_impl_; delete precalc_impl_; }
bool IsPrime(int n) const override { if (precalc_impl_ != nullptr && n < max_precalculated_) return precalc_impl_->IsPrime(n); else return on_the_fly_impl_->IsPrime(n); }
int GetNextPrime(int p) const override { int next_prime = -1; if (precalc_impl_ != nullptr && 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::tuple<bool, int> > { protected: void SetUp() override { bool force_on_the_fly; int max_precalculated; std::tie(force_on_the_fly, max_precalculated) = GetParam(); table_ = new HybridPrimeTable(force_on_the_fly, max_precalculated); } void TearDown() override { delete table_; table_ = nullptr; } 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_SUITE_P(MeaningfulTestParameters, PrimeTableTest, Combine(Bool(), Values(1, 10)));
} // namespace
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