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 (at) 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. 50 class 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 83 using ::testing::TestWithParam; 84 using ::testing::Bool; 85 using ::testing::Values; 86 using ::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. 93 class 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 }; 114 115 TEST_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 } 129 130 TEST_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 } 138 139 TEST_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. 159 INSTANTIATE_TEST_CASE_P(MeaningfulTestParameters, 160 PrimeTableTest, 161 Combine(Bool(), Values(1, 10))); 162 163 #else 164 165 // Google Test doesn't support Combine() on some platforms and compilers, 166 // such as MSVC 7.1. If we use conditional compilation to compile out 167 // all code referring to the gtest_main library, MSVC linker will not 168 // link that library at all and consequently complain about missing entry 169 // point defined in that library (fatal error LNK1561: entry point must 170 // be defined). This dummy test keeps gtest_main linked in. 171 TEST(DummyTest, CombineIsNotSupportedOnThisPlatform) {} 172 173 #endif // GTEST_HAS_COMBINE 174
