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