sample6_unittest.cc (8982B)
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 common properties of multiple 32 // implementations of the same interface (aka interface tests). 33 34 // The interface and its implementations are in this header. 35 #include "prime_tables.h" 36 37 #include "gtest/gtest.h" 38 namespace { 39 // First, we define some factory functions for creating instances of 40 // the implementations. You may be able to skip this step if all your 41 // implementations can be constructed the same way. 42 43 template <class T> 44 PrimeTable* CreatePrimeTable(); 45 46 template <> 47 PrimeTable* CreatePrimeTable<OnTheFlyPrimeTable>() { 48 return new OnTheFlyPrimeTable; 49 } 50 51 template <> 52 PrimeTable* CreatePrimeTable<PreCalculatedPrimeTable>() { 53 return new PreCalculatedPrimeTable(10000); 54 } 55 56 // Then we define a test fixture class template. 57 template <class T> 58 class PrimeTableTest : public testing::Test { 59 protected: 60 // The ctor calls the factory function to create a prime table 61 // implemented by T. 62 PrimeTableTest() : table_(CreatePrimeTable<T>()) {} 63 64 ~PrimeTableTest() override { delete table_; } 65 66 // Note that we test an implementation via the base interface 67 // instead of the actual implementation class. This is important 68 // for keeping the tests close to the real world scenario, where the 69 // implementation is invoked via the base interface. It avoids 70 // got-yas where the implementation class has a method that shadows 71 // a method with the same name (but slightly different argument 72 // types) in the base interface, for example. 73 PrimeTable* const table_; 74 }; 75 76 #if GTEST_HAS_TYPED_TEST 77 78 using testing::Types; 79 80 // Google Test offers two ways for reusing tests for different types. 81 // The first is called "typed tests". You should use it if you 82 // already know *all* the types you are gonna exercise when you write 83 // the tests. 84 85 // To write a typed test case, first use 86 // 87 // TYPED_TEST_SUITE(TestCaseName, TypeList); 88 // 89 // to declare it and specify the type parameters. As with TEST_F, 90 // TestCaseName must match the test fixture name. 91 92 // The list of types we want to test. 93 typedef Types<OnTheFlyPrimeTable, PreCalculatedPrimeTable> Implementations; 94 95 TYPED_TEST_SUITE(PrimeTableTest, Implementations); 96 97 // Then use TYPED_TEST(TestCaseName, TestName) to define a typed test, 98 // similar to TEST_F. 99 TYPED_TEST(PrimeTableTest, ReturnsFalseForNonPrimes) { 100 // Inside the test body, you can refer to the type parameter by 101 // TypeParam, and refer to the fixture class by TestFixture. We 102 // don't need them in this example. 103 104 // Since we are in the template world, C++ requires explicitly 105 // writing 'this->' when referring to members of the fixture class. 106 // This is something you have to learn to live with. 107 EXPECT_FALSE(this->table_->IsPrime(-5)); 108 EXPECT_FALSE(this->table_->IsPrime(0)); 109 EXPECT_FALSE(this->table_->IsPrime(1)); 110 EXPECT_FALSE(this->table_->IsPrime(4)); 111 EXPECT_FALSE(this->table_->IsPrime(6)); 112 EXPECT_FALSE(this->table_->IsPrime(100)); 113 } 114 115 TYPED_TEST(PrimeTableTest, ReturnsTrueForPrimes) { 116 EXPECT_TRUE(this->table_->IsPrime(2)); 117 EXPECT_TRUE(this->table_->IsPrime(3)); 118 EXPECT_TRUE(this->table_->IsPrime(5)); 119 EXPECT_TRUE(this->table_->IsPrime(7)); 120 EXPECT_TRUE(this->table_->IsPrime(11)); 121 EXPECT_TRUE(this->table_->IsPrime(131)); 122 } 123 124 TYPED_TEST(PrimeTableTest, CanGetNextPrime) { 125 EXPECT_EQ(2, this->table_->GetNextPrime(0)); 126 EXPECT_EQ(3, this->table_->GetNextPrime(2)); 127 EXPECT_EQ(5, this->table_->GetNextPrime(3)); 128 EXPECT_EQ(7, this->table_->GetNextPrime(5)); 129 EXPECT_EQ(11, this->table_->GetNextPrime(7)); 130 EXPECT_EQ(131, this->table_->GetNextPrime(128)); 131 } 132 133 // That's it! Google Test will repeat each TYPED_TEST for each type 134 // in the type list specified in TYPED_TEST_SUITE. Sit back and be 135 // happy that you don't have to define them multiple times. 136 137 #endif // GTEST_HAS_TYPED_TEST 138 139 #if GTEST_HAS_TYPED_TEST_P 140 141 using testing::Types; 142 143 // Sometimes, however, you don't yet know all the types that you want 144 // to test when you write the tests. For example, if you are the 145 // author of an interface and expect other people to implement it, you 146 // might want to write a set of tests to make sure each implementation 147 // conforms to some basic requirements, but you don't know what 148 // implementations will be written in the future. 149 // 150 // How can you write the tests without committing to the type 151 // parameters? That's what "type-parameterized tests" can do for you. 152 // It is a bit more involved than typed tests, but in return you get a 153 // test pattern that can be reused in many contexts, which is a big 154 // win. Here's how you do it: 155 156 // First, define a test fixture class template. Here we just reuse 157 // the PrimeTableTest fixture defined earlier: 158 159 template <class T> 160 class PrimeTableTest2 : public PrimeTableTest<T> { 161 }; 162 163 // Then, declare the test case. The argument is the name of the test 164 // fixture, and also the name of the test case (as usual). The _P 165 // suffix is for "parameterized" or "pattern". 166 TYPED_TEST_SUITE_P(PrimeTableTest2); 167 168 // Next, use TYPED_TEST_P(TestCaseName, TestName) to define a test, 169 // similar to what you do with TEST_F. 170 TYPED_TEST_P(PrimeTableTest2, ReturnsFalseForNonPrimes) { 171 EXPECT_FALSE(this->table_->IsPrime(-5)); 172 EXPECT_FALSE(this->table_->IsPrime(0)); 173 EXPECT_FALSE(this->table_->IsPrime(1)); 174 EXPECT_FALSE(this->table_->IsPrime(4)); 175 EXPECT_FALSE(this->table_->IsPrime(6)); 176 EXPECT_FALSE(this->table_->IsPrime(100)); 177 } 178 179 TYPED_TEST_P(PrimeTableTest2, ReturnsTrueForPrimes) { 180 EXPECT_TRUE(this->table_->IsPrime(2)); 181 EXPECT_TRUE(this->table_->IsPrime(3)); 182 EXPECT_TRUE(this->table_->IsPrime(5)); 183 EXPECT_TRUE(this->table_->IsPrime(7)); 184 EXPECT_TRUE(this->table_->IsPrime(11)); 185 EXPECT_TRUE(this->table_->IsPrime(131)); 186 } 187 188 TYPED_TEST_P(PrimeTableTest2, CanGetNextPrime) { 189 EXPECT_EQ(2, this->table_->GetNextPrime(0)); 190 EXPECT_EQ(3, this->table_->GetNextPrime(2)); 191 EXPECT_EQ(5, this->table_->GetNextPrime(3)); 192 EXPECT_EQ(7, this->table_->GetNextPrime(5)); 193 EXPECT_EQ(11, this->table_->GetNextPrime(7)); 194 EXPECT_EQ(131, this->table_->GetNextPrime(128)); 195 } 196 197 // Type-parameterized tests involve one extra step: you have to 198 // enumerate the tests you defined: 199 REGISTER_TYPED_TEST_SUITE_P( 200 PrimeTableTest2, // The first argument is the test case name. 201 // The rest of the arguments are the test names. 202 ReturnsFalseForNonPrimes, ReturnsTrueForPrimes, CanGetNextPrime); 203 204 // At this point the test pattern is done. However, you don't have 205 // any real test yet as you haven't said which types you want to run 206 // the tests with. 207 208 // To turn the abstract test pattern into real tests, you instantiate 209 // it with a list of types. Usually the test pattern will be defined 210 // in a .h file, and anyone can #include and instantiate it. You can 211 // even instantiate it more than once in the same program. To tell 212 // different instances apart, you give each of them a name, which will 213 // become part of the test case name and can be used in test filters. 214 215 // The list of types we want to test. Note that it doesn't have to be 216 // defined at the time we write the TYPED_TEST_P()s. 217 typedef Types<OnTheFlyPrimeTable, PreCalculatedPrimeTable> 218 PrimeTableImplementations; 219 INSTANTIATE_TYPED_TEST_SUITE_P(OnTheFlyAndPreCalculated, // Instance name 220 PrimeTableTest2, // Test case name 221 PrimeTableImplementations); // Type list 222 223 #endif // GTEST_HAS_TYPED_TEST_P 224 } // namespace