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: wan (at) google.com (Zhanyong Wan) 31 32 // This sample shows how to test common properties of multiple 33 // implementations of the same interface (aka interface tests). 34 35 // The interface and its implementations are in this header. 36 #include "prime_tables.h" 37 38 #include <gtest/gtest.h> 39 40 // First, we define some factory functions for creating instances of 41 // the implementations. You may be able to skip this step if all your 42 // implementations can be constructed the same way. 43 44 template <class T> 45 PrimeTable* CreatePrimeTable(); 46 47 template <> 48 PrimeTable* CreatePrimeTable<OnTheFlyPrimeTable>() { 49 return new OnTheFlyPrimeTable; 50 } 51 52 template <> 53 PrimeTable* CreatePrimeTable<PreCalculatedPrimeTable>() { 54 return new PreCalculatedPrimeTable(10000); 55 } 56 57 // Then we define a test fixture class template. 58 template <class T> 59 class PrimeTableTest : public testing::Test { 60 protected: 61 // The ctor calls the factory function to create a prime table 62 // implemented by T. 63 PrimeTableTest() : table_(CreatePrimeTable<T>()) {} 64 65 virtual ~PrimeTableTest() { delete table_; } 66 67 // Note that we test an implementation via the base interface 68 // instead of the actual implementation class. This is important 69 // for keeping the tests close to the real world scenario, where the 70 // implementation is invoked via the base interface. It avoids 71 // got-yas where the implementation class has a method that shadows 72 // a method with the same name (but slightly different argument 73 // types) in the base interface, for example. 74 PrimeTable* const table_; 75 }; 76 77 #if GTEST_HAS_TYPED_TEST 78 79 using testing::Types; 80 81 // Google Test offers two ways for reusing tests for different types. 82 // The first is called "typed tests". You should use it if you 83 // already know *all* the types you are gonna exercise when you write 84 // the tests. 85 86 // To write a typed test case, first use 87 // 88 // TYPED_TEST_CASE(TestCaseName, TypeList); 89 // 90 // to declare it and specify the type parameters. As with TEST_F, 91 // TestCaseName must match the test fixture name. 92 93 // The list of types we want to test. 94 typedef Types<OnTheFlyPrimeTable, PreCalculatedPrimeTable> Implementations; 95 96 TYPED_TEST_CASE(PrimeTableTest, Implementations); 97 98 // Then use TYPED_TEST(TestCaseName, TestName) to define a typed test, 99 // similar to TEST_F. 100 TYPED_TEST(PrimeTableTest, ReturnsFalseForNonPrimes) { 101 // Inside the test body, you can refer to the type parameter by 102 // TypeParam, and refer to the fixture class by TestFixture. We 103 // don't need them in this example. 104 105 // Since we are in the template world, C++ requires explicitly 106 // writing 'this->' when referring to members of the fixture class. 107 // This is something you have to learn to live with. 108 EXPECT_FALSE(this->table_->IsPrime(-5)); 109 EXPECT_FALSE(this->table_->IsPrime(0)); 110 EXPECT_FALSE(this->table_->IsPrime(1)); 111 EXPECT_FALSE(this->table_->IsPrime(4)); 112 EXPECT_FALSE(this->table_->IsPrime(6)); 113 EXPECT_FALSE(this->table_->IsPrime(100)); 114 } 115 116 TYPED_TEST(PrimeTableTest, ReturnsTrueForPrimes) { 117 EXPECT_TRUE(this->table_->IsPrime(2)); 118 EXPECT_TRUE(this->table_->IsPrime(3)); 119 EXPECT_TRUE(this->table_->IsPrime(5)); 120 EXPECT_TRUE(this->table_->IsPrime(7)); 121 EXPECT_TRUE(this->table_->IsPrime(11)); 122 EXPECT_TRUE(this->table_->IsPrime(131)); 123 } 124 125 TYPED_TEST(PrimeTableTest, CanGetNextPrime) { 126 EXPECT_EQ(2, this->table_->GetNextPrime(0)); 127 EXPECT_EQ(3, this->table_->GetNextPrime(2)); 128 EXPECT_EQ(5, this->table_->GetNextPrime(3)); 129 EXPECT_EQ(7, this->table_->GetNextPrime(5)); 130 EXPECT_EQ(11, this->table_->GetNextPrime(7)); 131 EXPECT_EQ(131, this->table_->GetNextPrime(128)); 132 } 133 134 // That's it! Google Test will repeat each TYPED_TEST for each type 135 // in the type list specified in TYPED_TEST_CASE. Sit back and be 136 // happy that you don't have to define them multiple times. 137 138 #endif // GTEST_HAS_TYPED_TEST 139 140 #if GTEST_HAS_TYPED_TEST_P 141 142 using testing::Types; 143 144 // Sometimes, however, you don't yet know all the types that you want 145 // to test when you write the tests. For example, if you are the 146 // author of an interface and expect other people to implement it, you 147 // might want to write a set of tests to make sure each implementation 148 // conforms to some basic requirements, but you don't know what 149 // implementations will be written in the future. 150 // 151 // How can you write the tests without committing to the type 152 // parameters? That's what "type-parameterized tests" can do for you. 153 // It is a bit more involved than typed tests, but in return you get a 154 // test pattern that can be reused in many contexts, which is a big 155 // win. Here's how you do it: 156 157 // First, define a test fixture class template. Here we just reuse 158 // the PrimeTableTest fixture defined earlier: 159 160 template <class T> 161 class PrimeTableTest2 : public PrimeTableTest<T> { 162 }; 163 164 // Then, declare the test case. The argument is the name of the test 165 // fixture, and also the name of the test case (as usual). The _P 166 // suffix is for "parameterized" or "pattern". 167 TYPED_TEST_CASE_P(PrimeTableTest2); 168 169 // Next, use TYPED_TEST_P(TestCaseName, TestName) to define a test, 170 // similar to what you do with TEST_F. 171 TYPED_TEST_P(PrimeTableTest2, ReturnsFalseForNonPrimes) { 172 EXPECT_FALSE(this->table_->IsPrime(-5)); 173 EXPECT_FALSE(this->table_->IsPrime(0)); 174 EXPECT_FALSE(this->table_->IsPrime(1)); 175 EXPECT_FALSE(this->table_->IsPrime(4)); 176 EXPECT_FALSE(this->table_->IsPrime(6)); 177 EXPECT_FALSE(this->table_->IsPrime(100)); 178 } 179 180 TYPED_TEST_P(PrimeTableTest2, ReturnsTrueForPrimes) { 181 EXPECT_TRUE(this->table_->IsPrime(2)); 182 EXPECT_TRUE(this->table_->IsPrime(3)); 183 EXPECT_TRUE(this->table_->IsPrime(5)); 184 EXPECT_TRUE(this->table_->IsPrime(7)); 185 EXPECT_TRUE(this->table_->IsPrime(11)); 186 EXPECT_TRUE(this->table_->IsPrime(131)); 187 } 188 189 TYPED_TEST_P(PrimeTableTest2, CanGetNextPrime) { 190 EXPECT_EQ(2, this->table_->GetNextPrime(0)); 191 EXPECT_EQ(3, this->table_->GetNextPrime(2)); 192 EXPECT_EQ(5, this->table_->GetNextPrime(3)); 193 EXPECT_EQ(7, this->table_->GetNextPrime(5)); 194 EXPECT_EQ(11, this->table_->GetNextPrime(7)); 195 EXPECT_EQ(131, this->table_->GetNextPrime(128)); 196 } 197 198 // Type-parameterized tests involve one extra step: you have to 199 // enumerate the tests you defined: 200 REGISTER_TYPED_TEST_CASE_P( 201 PrimeTableTest2, // The first argument is the test case name. 202 // The rest of the arguments are the test names. 203 ReturnsFalseForNonPrimes, ReturnsTrueForPrimes, CanGetNextPrime); 204 205 // At this point the test pattern is done. However, you don't have 206 // any real test yet as you haven't said which types you want to run 207 // the tests with. 208 209 // To turn the abstract test pattern into real tests, you instantiate 210 // it with a list of types. Usually the test pattern will be defined 211 // in a .h file, and anyone can #include and instantiate it. You can 212 // even instantiate it more than once in the same program. To tell 213 // different instances apart, you give each of them a name, which will 214 // become part of the test case name and can be used in test filters. 215 216 // The list of types we want to test. Note that it doesn't have to be 217 // defined at the time we write the TYPED_TEST_P()s. 218 typedef Types<OnTheFlyPrimeTable, PreCalculatedPrimeTable> 219 PrimeTableImplementations; 220 INSTANTIATE_TYPED_TEST_CASE_P(OnTheFlyAndPreCalculated, // Instance name 221 PrimeTableTest2, // Test case name 222 PrimeTableImplementations); // Type list 223 224 #endif // GTEST_HAS_TYPED_TEST_P 225
