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1 // Copyright 2008 Google Inc. |
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2 // All Rights Reserved. |
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3 // |
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4 // Redistribution and use in source and binary forms, with or without |
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5 // modification, are permitted provided that the following conditions are |
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6 // met: |
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7 // |
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8 // * Redistributions of source code must retain the above copyright |
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9 // notice, this list of conditions and the following disclaimer. |
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10 // * Redistributions in binary form must reproduce the above |
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11 // copyright notice, this list of conditions and the following disclaimer |
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12 // in the documentation and/or other materials provided with the |
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13 // distribution. |
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14 // * Neither the name of Google Inc. nor the names of its |
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15 // contributors may be used to endorse or promote products derived from |
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16 // this software without specific prior written permission. |
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17 // |
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18 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
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19 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
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20 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
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21 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
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22 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
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23 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
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24 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
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25 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
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26 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
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27 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
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28 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
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29 // |
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30 // Author: wan@google.com (Zhanyong Wan) |
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31 |
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32 // This sample shows how to test common properties of multiple |
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33 // implementations of the same interface (aka interface tests). |
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34 |
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35 // The interface and its implementations are in this header. |
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36 #include "prime_tables.h" |
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37 |
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38 #include "gtest/gtest.h" |
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39 |
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40 // First, we define some factory functions for creating instances of |
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41 // the implementations. You may be able to skip this step if all your |
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42 // implementations can be constructed the same way. |
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43 |
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44 template <class T> |
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45 PrimeTable* CreatePrimeTable(); |
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46 |
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47 template <> |
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48 PrimeTable* CreatePrimeTable<OnTheFlyPrimeTable>() { |
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49 return new OnTheFlyPrimeTable; |
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50 } |
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51 |
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52 template <> |
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53 PrimeTable* CreatePrimeTable<PreCalculatedPrimeTable>() { |
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54 return new PreCalculatedPrimeTable(10000); |
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55 } |
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56 |
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57 // Then we define a test fixture class template. |
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58 template <class T> |
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59 class PrimeTableTest : public testing::Test { |
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60 protected: |
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61 // The ctor calls the factory function to create a prime table |
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62 // implemented by T. |
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63 PrimeTableTest() : table_(CreatePrimeTable<T>()) {} |
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64 |
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65 virtual ~PrimeTableTest() { delete table_; } |
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66 |
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67 // Note that we test an implementation via the base interface |
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68 // instead of the actual implementation class. This is important |
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69 // for keeping the tests close to the real world scenario, where the |
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70 // implementation is invoked via the base interface. It avoids |
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71 // got-yas where the implementation class has a method that shadows |
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72 // a method with the same name (but slightly different argument |
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73 // types) in the base interface, for example. |
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74 PrimeTable* const table_; |
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75 }; |
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76 |
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77 #if GTEST_HAS_TYPED_TEST |
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78 |
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79 using testing::Types; |
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80 |
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81 // Google Test offers two ways for reusing tests for different types. |
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82 // The first is called "typed tests". You should use it if you |
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83 // already know *all* the types you are gonna exercise when you write |
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84 // the tests. |
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85 |
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86 // To write a typed test case, first use |
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87 // |
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88 // TYPED_TEST_CASE(TestCaseName, TypeList); |
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89 // |
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90 // to declare it and specify the type parameters. As with TEST_F, |
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91 // TestCaseName must match the test fixture name. |
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92 |
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93 // The list of types we want to test. |
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94 typedef Types<OnTheFlyPrimeTable, PreCalculatedPrimeTable> Implementations; |
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95 |
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96 TYPED_TEST_CASE(PrimeTableTest, Implementations); |
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97 |
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98 // Then use TYPED_TEST(TestCaseName, TestName) to define a typed test, |
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99 // similar to TEST_F. |
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100 TYPED_TEST(PrimeTableTest, ReturnsFalseForNonPrimes) { |
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101 // Inside the test body, you can refer to the type parameter by |
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102 // TypeParam, and refer to the fixture class by TestFixture. We |
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103 // don't need them in this example. |
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104 |
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105 // Since we are in the template world, C++ requires explicitly |
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106 // writing 'this->' when referring to members of the fixture class. |
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107 // This is something you have to learn to live with. |
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108 EXPECT_FALSE(this->table_->IsPrime(-5)); |
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109 EXPECT_FALSE(this->table_->IsPrime(0)); |
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110 EXPECT_FALSE(this->table_->IsPrime(1)); |
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111 EXPECT_FALSE(this->table_->IsPrime(4)); |
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112 EXPECT_FALSE(this->table_->IsPrime(6)); |
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113 EXPECT_FALSE(this->table_->IsPrime(100)); |
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114 } |
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115 |
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116 TYPED_TEST(PrimeTableTest, ReturnsTrueForPrimes) { |
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117 EXPECT_TRUE(this->table_->IsPrime(2)); |
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118 EXPECT_TRUE(this->table_->IsPrime(3)); |
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119 EXPECT_TRUE(this->table_->IsPrime(5)); |
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120 EXPECT_TRUE(this->table_->IsPrime(7)); |
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121 EXPECT_TRUE(this->table_->IsPrime(11)); |
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122 EXPECT_TRUE(this->table_->IsPrime(131)); |
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123 } |
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124 |
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125 TYPED_TEST(PrimeTableTest, CanGetNextPrime) { |
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126 EXPECT_EQ(2, this->table_->GetNextPrime(0)); |
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127 EXPECT_EQ(3, this->table_->GetNextPrime(2)); |
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128 EXPECT_EQ(5, this->table_->GetNextPrime(3)); |
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129 EXPECT_EQ(7, this->table_->GetNextPrime(5)); |
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130 EXPECT_EQ(11, this->table_->GetNextPrime(7)); |
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131 EXPECT_EQ(131, this->table_->GetNextPrime(128)); |
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132 } |
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133 |
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134 // That's it! Google Test will repeat each TYPED_TEST for each type |
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135 // in the type list specified in TYPED_TEST_CASE. Sit back and be |
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136 // happy that you don't have to define them multiple times. |
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137 |
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138 #endif // GTEST_HAS_TYPED_TEST |
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139 |
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140 #if GTEST_HAS_TYPED_TEST_P |
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141 |
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142 using testing::Types; |
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143 |
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144 // Sometimes, however, you don't yet know all the types that you want |
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145 // to test when you write the tests. For example, if you are the |
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146 // author of an interface and expect other people to implement it, you |
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147 // might want to write a set of tests to make sure each implementation |
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148 // conforms to some basic requirements, but you don't know what |
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149 // implementations will be written in the future. |
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150 // |
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151 // How can you write the tests without committing to the type |
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152 // parameters? That's what "type-parameterized tests" can do for you. |
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153 // It is a bit more involved than typed tests, but in return you get a |
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154 // test pattern that can be reused in many contexts, which is a big |
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155 // win. Here's how you do it: |
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156 |
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157 // First, define a test fixture class template. Here we just reuse |
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158 // the PrimeTableTest fixture defined earlier: |
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159 |
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160 template <class T> |
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161 class PrimeTableTest2 : public PrimeTableTest<T> { |
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162 }; |
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163 |
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164 // Then, declare the test case. The argument is the name of the test |
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165 // fixture, and also the name of the test case (as usual). The _P |
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166 // suffix is for "parameterized" or "pattern". |
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167 TYPED_TEST_CASE_P(PrimeTableTest2); |
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168 |
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169 // Next, use TYPED_TEST_P(TestCaseName, TestName) to define a test, |
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170 // similar to what you do with TEST_F. |
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171 TYPED_TEST_P(PrimeTableTest2, ReturnsFalseForNonPrimes) { |
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172 EXPECT_FALSE(this->table_->IsPrime(-5)); |
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173 EXPECT_FALSE(this->table_->IsPrime(0)); |
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174 EXPECT_FALSE(this->table_->IsPrime(1)); |
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175 EXPECT_FALSE(this->table_->IsPrime(4)); |
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176 EXPECT_FALSE(this->table_->IsPrime(6)); |
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177 EXPECT_FALSE(this->table_->IsPrime(100)); |
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178 } |
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179 |
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180 TYPED_TEST_P(PrimeTableTest2, ReturnsTrueForPrimes) { |
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181 EXPECT_TRUE(this->table_->IsPrime(2)); |
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182 EXPECT_TRUE(this->table_->IsPrime(3)); |
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183 EXPECT_TRUE(this->table_->IsPrime(5)); |
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184 EXPECT_TRUE(this->table_->IsPrime(7)); |
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185 EXPECT_TRUE(this->table_->IsPrime(11)); |
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186 EXPECT_TRUE(this->table_->IsPrime(131)); |
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187 } |
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188 |
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189 TYPED_TEST_P(PrimeTableTest2, CanGetNextPrime) { |
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190 EXPECT_EQ(2, this->table_->GetNextPrime(0)); |
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191 EXPECT_EQ(3, this->table_->GetNextPrime(2)); |
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192 EXPECT_EQ(5, this->table_->GetNextPrime(3)); |
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193 EXPECT_EQ(7, this->table_->GetNextPrime(5)); |
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194 EXPECT_EQ(11, this->table_->GetNextPrime(7)); |
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195 EXPECT_EQ(131, this->table_->GetNextPrime(128)); |
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196 } |
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197 |
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198 // Type-parameterized tests involve one extra step: you have to |
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199 // enumerate the tests you defined: |
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200 REGISTER_TYPED_TEST_CASE_P( |
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201 PrimeTableTest2, // The first argument is the test case name. |
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202 // The rest of the arguments are the test names. |
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203 ReturnsFalseForNonPrimes, ReturnsTrueForPrimes, CanGetNextPrime); |
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204 |
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205 // At this point the test pattern is done. However, you don't have |
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206 // any real test yet as you haven't said which types you want to run |
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207 // the tests with. |
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208 |
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209 // To turn the abstract test pattern into real tests, you instantiate |
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210 // it with a list of types. Usually the test pattern will be defined |
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211 // in a .h file, and anyone can #include and instantiate it. You can |
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212 // even instantiate it more than once in the same program. To tell |
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213 // different instances apart, you give each of them a name, which will |
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214 // become part of the test case name and can be used in test filters. |
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215 |
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216 // The list of types we want to test. Note that it doesn't have to be |
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217 // defined at the time we write the TYPED_TEST_P()s. |
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218 typedef Types<OnTheFlyPrimeTable, PreCalculatedPrimeTable> |
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219 PrimeTableImplementations; |
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220 INSTANTIATE_TYPED_TEST_CASE_P(OnTheFlyAndPreCalculated, // Instance name |
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221 PrimeTableTest2, // Test case name |
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222 PrimeTableImplementations); // Type list |
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223 |
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224 #endif // GTEST_HAS_TYPED_TEST_P |