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 31 // This sample shows how to test code relying on some global flag variables. 32 // Combine() helps with generating all possible combinations of such flags, 33 // and each test is given one combination as a parameter. 34 35 // Use class definitions to test from this header. 36 #include "prime_tables.h" 37 38 #include "gtest/gtest.h" 39 namespace { 40 #if GTEST_HAS_COMBINE 41 42 // Suppose we want to introduce a new, improved implementation of PrimeTable 43 // which combines speed of PrecalcPrimeTable and versatility of 44 // OnTheFlyPrimeTable (see prime_tables.h). Inside it instantiates both 45 // PrecalcPrimeTable and OnTheFlyPrimeTable and uses the one that is more 46 // appropriate under the circumstances. But in low memory conditions, it can be 47 // told to instantiate without PrecalcPrimeTable instance at all and use only 48 // OnTheFlyPrimeTable. 49 class HybridPrimeTable : public PrimeTable { 50 public: 51 HybridPrimeTable(bool force_on_the_fly, int max_precalculated) 52 : on_the_fly_impl_(new OnTheFlyPrimeTable), 53 precalc_impl_(force_on_the_fly ? NULL : 54 new PreCalculatedPrimeTable(max_precalculated)), 55 max_precalculated_(max_precalculated) {} 56 virtual ~HybridPrimeTable() { 57 delete on_the_fly_impl_; 58 delete precalc_impl_; 59 } 60 61 virtual bool IsPrime(int n) const { 62 if (precalc_impl_ != NULL && n < max_precalculated_) 63 return precalc_impl_->IsPrime(n); 64 else 65 return on_the_fly_impl_->IsPrime(n); 66 } 67 68 virtual int GetNextPrime(int p) const { 69 int next_prime = -1; 70 if (precalc_impl_ != NULL && p < max_precalculated_) 71 next_prime = precalc_impl_->GetNextPrime(p); 72 73 return next_prime != -1 ? next_prime : on_the_fly_impl_->GetNextPrime(p); 74 } 75 76 private: 77 OnTheFlyPrimeTable* on_the_fly_impl_; 78 PreCalculatedPrimeTable* precalc_impl_; 79 int max_precalculated_; 80 }; 81 82 using ::testing::TestWithParam; 83 using ::testing::Bool; 84 using ::testing::Values; 85 using ::testing::Combine; 86 87 // To test all code paths for HybridPrimeTable we must test it with numbers 88 // both within and outside PreCalculatedPrimeTable's capacity and also with 89 // PreCalculatedPrimeTable disabled. We do this by defining fixture which will 90 // accept different combinations of parameters for instantiating a 91 // HybridPrimeTable instance. 92 class PrimeTableTest : public TestWithParam< ::testing::tuple<bool, int> > { 93 protected: 94 virtual void SetUp() { 95 // This can be written as 96 // 97 // bool force_on_the_fly; 98 // int max_precalculated; 99 // tie(force_on_the_fly, max_precalculated) = GetParam(); 100 // 101 // once the Google C++ Style Guide allows use of ::std::tr1::tie. 102 // 103 bool force_on_the_fly = ::testing::get<0>(GetParam()); 104 int max_precalculated = ::testing::get<1>(GetParam()); 105 table_ = new HybridPrimeTable(force_on_the_fly, max_precalculated); 106 } 107 virtual void TearDown() { 108 delete table_; 109 table_ = NULL; 110 } 111 HybridPrimeTable* table_; 112 }; 113 114 TEST_P(PrimeTableTest, ReturnsFalseForNonPrimes) { 115 // Inside the test body, you can refer to the test parameter by GetParam(). 116 // In this case, the test parameter is a PrimeTable interface pointer which 117 // we can use directly. 118 // Please note that you can also save it in the fixture's SetUp() method 119 // or constructor and use saved copy in the tests. 120 121 EXPECT_FALSE(table_->IsPrime(-5)); 122 EXPECT_FALSE(table_->IsPrime(0)); 123 EXPECT_FALSE(table_->IsPrime(1)); 124 EXPECT_FALSE(table_->IsPrime(4)); 125 EXPECT_FALSE(table_->IsPrime(6)); 126 EXPECT_FALSE(table_->IsPrime(100)); 127 } 128 129 TEST_P(PrimeTableTest, ReturnsTrueForPrimes) { 130 EXPECT_TRUE(table_->IsPrime(2)); 131 EXPECT_TRUE(table_->IsPrime(3)); 132 EXPECT_TRUE(table_->IsPrime(5)); 133 EXPECT_TRUE(table_->IsPrime(7)); 134 EXPECT_TRUE(table_->IsPrime(11)); 135 EXPECT_TRUE(table_->IsPrime(131)); 136 } 137 138 TEST_P(PrimeTableTest, CanGetNextPrime) { 139 EXPECT_EQ(2, table_->GetNextPrime(0)); 140 EXPECT_EQ(3, table_->GetNextPrime(2)); 141 EXPECT_EQ(5, table_->GetNextPrime(3)); 142 EXPECT_EQ(7, table_->GetNextPrime(5)); 143 EXPECT_EQ(11, table_->GetNextPrime(7)); 144 EXPECT_EQ(131, table_->GetNextPrime(128)); 145 } 146 147 // In order to run value-parameterized tests, you need to instantiate them, 148 // or bind them to a list of values which will be used as test parameters. 149 // You can instantiate them in a different translation module, or even 150 // instantiate them several times. 151 // 152 // Here, we instantiate our tests with a list of parameters. We must combine 153 // all variations of the boolean flag suppressing PrecalcPrimeTable and some 154 // meaningful values for tests. We choose a small value (1), and a value that 155 // will put some of the tested numbers beyond the capability of the 156 // PrecalcPrimeTable instance and some inside it (10). Combine will produce all 157 // possible combinations. 158 INSTANTIATE_TEST_CASE_P(MeaningfulTestParameters, 159 PrimeTableTest, 160 Combine(Bool(), Values(1, 10))); 161 162 #else 163 164 // Google Test may not support Combine() with some compilers. If we 165 // use conditional compilation to compile out all code referring to 166 // the gtest_main library, MSVC linker will not link that library at 167 // all and consequently complain about missing entry point defined in 168 // that library (fatal error LNK1561: entry point must be 169 // defined). This dummy test keeps gtest_main linked in. 170 TEST(DummyTest, CombineIsNotSupportedOnThisPlatform) {} 171 172 #endif // GTEST_HAS_COMBINE 173 } // namespace 174