1// Copyright 2008 Google Inc. 2// All Rights Reserved. 3// 4// Redistribution and use in source and binary forms, with or without 5// modification, are permitted provided that the following conditions are 6// met: 7// 8// * Redistributions of source code must retain the above copyright 9// notice, this list of conditions and the following disclaimer. 10// * Redistributions in binary form must reproduce the above 11// copyright notice, this list of conditions and the following disclaimer 12// in the documentation and/or other materials provided with the 13// distribution. 14// * Neither the name of Google Inc. nor the names of its 15// contributors may be used to endorse or promote products derived from 16// this software without specific prior written permission. 17// 18// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 19// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 20// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 21// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 22// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 23// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 24// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 25// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 26// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 27// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 28// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29// 30// Author: vladl@google.com (Vlad Losev) 31 32// This sample shows how to test code relying on some global flag variables. 33// Combine() helps with generating all possible combinations of such flags, 34// and each test is given one combination as a parameter. 35 36// Use class definitions to test from this header. 37#include "prime_tables.h" 38 39#include "gtest/gtest.h" 40 41#if GTEST_HAS_COMBINE 42 43// Suppose we want to introduce a new, improved implementation of PrimeTable 44// which combines speed of PrecalcPrimeTable and versatility of 45// OnTheFlyPrimeTable (see prime_tables.h). Inside it instantiates both 46// PrecalcPrimeTable and OnTheFlyPrimeTable and uses the one that is more 47// appropriate under the circumstances. But in low memory conditions, it can be 48// told to instantiate without PrecalcPrimeTable instance at all and use only 49// OnTheFlyPrimeTable. 50class HybridPrimeTable : public PrimeTable { 51 public: 52 HybridPrimeTable(bool force_on_the_fly, int max_precalculated) 53 : on_the_fly_impl_(new OnTheFlyPrimeTable), 54 precalc_impl_(force_on_the_fly ? NULL : 55 new PreCalculatedPrimeTable(max_precalculated)), 56 max_precalculated_(max_precalculated) {} 57 virtual ~HybridPrimeTable() { 58 delete on_the_fly_impl_; 59 delete precalc_impl_; 60 } 61 62 virtual bool IsPrime(int n) const { 63 if (precalc_impl_ != NULL && n < max_precalculated_) 64 return precalc_impl_->IsPrime(n); 65 else 66 return on_the_fly_impl_->IsPrime(n); 67 } 68 69 virtual int GetNextPrime(int p) const { 70 int next_prime = -1; 71 if (precalc_impl_ != NULL && p < max_precalculated_) 72 next_prime = precalc_impl_->GetNextPrime(p); 73 74 return next_prime != -1 ? next_prime : on_the_fly_impl_->GetNextPrime(p); 75 } 76 77 private: 78 OnTheFlyPrimeTable* on_the_fly_impl_; 79 PreCalculatedPrimeTable* precalc_impl_; 80 int max_precalculated_; 81}; 82 83using ::testing::TestWithParam; 84using ::testing::Bool; 85using ::testing::Values; 86using ::testing::Combine; 87 88// To test all code paths for HybridPrimeTable we must test it with numbers 89// both within and outside PreCalculatedPrimeTable's capacity and also with 90// PreCalculatedPrimeTable disabled. We do this by defining fixture which will 91// accept different combinations of parameters for instantiating a 92// HybridPrimeTable instance. 93class PrimeTableTest : public TestWithParam< ::std::tr1::tuple<bool, int> > { 94 protected: 95 virtual void SetUp() { 96 // This can be written as 97 // 98 // bool force_on_the_fly; 99 // int max_precalculated; 100 // tie(force_on_the_fly, max_precalculated) = GetParam(); 101 // 102 // once the Google C++ Style Guide allows use of ::std::tr1::tie. 103 // 104 bool force_on_the_fly = ::std::tr1::get<0>(GetParam()); 105 int max_precalculated = ::std::tr1::get<1>(GetParam()); 106 table_ = new HybridPrimeTable(force_on_the_fly, max_precalculated); 107 } 108 virtual void TearDown() { 109 delete table_; 110 table_ = NULL; 111 } 112 HybridPrimeTable* table_; 113}; 114 115TEST_P(PrimeTableTest, ReturnsFalseForNonPrimes) { 116 // Inside the test body, you can refer to the test parameter by GetParam(). 117 // In this case, the test parameter is a PrimeTable interface pointer which 118 // we can use directly. 119 // Please note that you can also save it in the fixture's SetUp() method 120 // or constructor and use saved copy in the tests. 121 122 EXPECT_FALSE(table_->IsPrime(-5)); 123 EXPECT_FALSE(table_->IsPrime(0)); 124 EXPECT_FALSE(table_->IsPrime(1)); 125 EXPECT_FALSE(table_->IsPrime(4)); 126 EXPECT_FALSE(table_->IsPrime(6)); 127 EXPECT_FALSE(table_->IsPrime(100)); 128} 129 130TEST_P(PrimeTableTest, ReturnsTrueForPrimes) { 131 EXPECT_TRUE(table_->IsPrime(2)); 132 EXPECT_TRUE(table_->IsPrime(3)); 133 EXPECT_TRUE(table_->IsPrime(5)); 134 EXPECT_TRUE(table_->IsPrime(7)); 135 EXPECT_TRUE(table_->IsPrime(11)); 136 EXPECT_TRUE(table_->IsPrime(131)); 137} 138 139TEST_P(PrimeTableTest, CanGetNextPrime) { 140 EXPECT_EQ(2, table_->GetNextPrime(0)); 141 EXPECT_EQ(3, table_->GetNextPrime(2)); 142 EXPECT_EQ(5, table_->GetNextPrime(3)); 143 EXPECT_EQ(7, table_->GetNextPrime(5)); 144 EXPECT_EQ(11, table_->GetNextPrime(7)); 145 EXPECT_EQ(131, table_->GetNextPrime(128)); 146} 147 148// In order to run value-parameterized tests, you need to instantiate them, 149// or bind them to a list of values which will be used as test parameters. 150// You can instantiate them in a different translation module, or even 151// instantiate them several times. 152// 153// Here, we instantiate our tests with a list of parameters. We must combine 154// all variations of the boolean flag suppressing PrecalcPrimeTable and some 155// meaningful values for tests. We choose a small value (1), and a value that 156// will put some of the tested numbers beyond the capability of the 157// PrecalcPrimeTable instance and some inside it (10). Combine will produce all 158// possible combinations. 159INSTANTIATE_TEST_CASE_P(MeaningfulTestParameters, 160 PrimeTableTest, 161 Combine(Bool(), Values(1, 10))); 162 163#else 164 165// Google Test may not support Combine() with some compilers. If we 166// use conditional compilation to compile out all code referring to 167// the gtest_main library, MSVC linker will not link that library at 168// all and consequently complain about missing entry point defined in 169// that library (fatal error LNK1561: entry point must be 170// defined). This dummy test keeps gtest_main linked in. 171TEST(DummyTest, CombineIsNotSupportedOnThisPlatform) {} 172 173#endif // GTEST_HAS_COMBINE 174