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  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. // This sample shows how to test code relying on some global flag variables.
  30. // Combine() helps with generating all possible combinations of such flags,
  31. // and each test is given one combination as a parameter.
  32. // Use class definitions to test from this header.
  33. #include "prime_tables.h"
  34. #include "gtest/gtest.h"
  35. namespace {
  36. // Suppose we want to introduce a new, improved implementation of PrimeTable
  37. // which combines speed of PrecalcPrimeTable and versatility of
  38. // OnTheFlyPrimeTable (see prime_tables.h). Inside it instantiates both
  39. // PrecalcPrimeTable and OnTheFlyPrimeTable and uses the one that is more
  40. // appropriate under the circumstances. But in low memory conditions, it can be
  41. // told to instantiate without PrecalcPrimeTable instance at all and use only
  42. // OnTheFlyPrimeTable.
  43. class HybridPrimeTable : public PrimeTable {
  44. public:
  45. HybridPrimeTable(bool force_on_the_fly, int max_precalculated)
  46. : on_the_fly_impl_(new OnTheFlyPrimeTable),
  47. precalc_impl_(force_on_the_fly
  48. ? nullptr
  49. : new PreCalculatedPrimeTable(max_precalculated)),
  50. max_precalculated_(max_precalculated) {}
  51. ~HybridPrimeTable() override {
  52. delete on_the_fly_impl_;
  53. delete precalc_impl_;
  54. }
  55. bool IsPrime(int n) const override {
  56. if (precalc_impl_ != nullptr && n < max_precalculated_)
  57. return precalc_impl_->IsPrime(n);
  58. else
  59. return on_the_fly_impl_->IsPrime(n);
  60. }
  61. int GetNextPrime(int p) const override {
  62. int next_prime = -1;
  63. if (precalc_impl_ != nullptr && p < max_precalculated_)
  64. next_prime = precalc_impl_->GetNextPrime(p);
  65. return next_prime != -1 ? next_prime : on_the_fly_impl_->GetNextPrime(p);
  66. }
  67. private:
  68. OnTheFlyPrimeTable* on_the_fly_impl_;
  69. PreCalculatedPrimeTable* precalc_impl_;
  70. int max_precalculated_;
  71. };
  72. using ::testing::TestWithParam;
  73. using ::testing::Bool;
  74. using ::testing::Values;
  75. using ::testing::Combine;
  76. // To test all code paths for HybridPrimeTable we must test it with numbers
  77. // both within and outside PreCalculatedPrimeTable's capacity and also with
  78. // PreCalculatedPrimeTable disabled. We do this by defining fixture which will
  79. // accept different combinations of parameters for instantiating a
  80. // HybridPrimeTable instance.
  81. class PrimeTableTest : public TestWithParam< ::std::tuple<bool, int> > {
  82. protected:
  83. void SetUp() override {
  84. bool force_on_the_fly;
  85. int max_precalculated;
  86. std::tie(force_on_the_fly, max_precalculated) = GetParam();
  87. table_ = new HybridPrimeTable(force_on_the_fly, max_precalculated);
  88. }
  89. void TearDown() override {
  90. delete table_;
  91. table_ = nullptr;
  92. }
  93. HybridPrimeTable* table_;
  94. };
  95. TEST_P(PrimeTableTest, ReturnsFalseForNonPrimes) {
  96. // Inside the test body, you can refer to the test parameter by GetParam().
  97. // In this case, the test parameter is a PrimeTable interface pointer which
  98. // we can use directly.
  99. // Please note that you can also save it in the fixture's SetUp() method
  100. // or constructor and use saved copy in the tests.
  101. EXPECT_FALSE(table_->IsPrime(-5));
  102. EXPECT_FALSE(table_->IsPrime(0));
  103. EXPECT_FALSE(table_->IsPrime(1));
  104. EXPECT_FALSE(table_->IsPrime(4));
  105. EXPECT_FALSE(table_->IsPrime(6));
  106. EXPECT_FALSE(table_->IsPrime(100));
  107. }
  108. TEST_P(PrimeTableTest, ReturnsTrueForPrimes) {
  109. EXPECT_TRUE(table_->IsPrime(2));
  110. EXPECT_TRUE(table_->IsPrime(3));
  111. EXPECT_TRUE(table_->IsPrime(5));
  112. EXPECT_TRUE(table_->IsPrime(7));
  113. EXPECT_TRUE(table_->IsPrime(11));
  114. EXPECT_TRUE(table_->IsPrime(131));
  115. }
  116. TEST_P(PrimeTableTest, CanGetNextPrime) {
  117. EXPECT_EQ(2, table_->GetNextPrime(0));
  118. EXPECT_EQ(3, table_->GetNextPrime(2));
  119. EXPECT_EQ(5, table_->GetNextPrime(3));
  120. EXPECT_EQ(7, table_->GetNextPrime(5));
  121. EXPECT_EQ(11, table_->GetNextPrime(7));
  122. EXPECT_EQ(131, table_->GetNextPrime(128));
  123. }
  124. // In order to run value-parameterized tests, you need to instantiate them,
  125. // or bind them to a list of values which will be used as test parameters.
  126. // You can instantiate them in a different translation module, or even
  127. // instantiate them several times.
  128. //
  129. // Here, we instantiate our tests with a list of parameters. We must combine
  130. // all variations of the boolean flag suppressing PrecalcPrimeTable and some
  131. // meaningful values for tests. We choose a small value (1), and a value that
  132. // will put some of the tested numbers beyond the capability of the
  133. // PrecalcPrimeTable instance and some inside it (10). Combine will produce all
  134. // possible combinations.
  135. INSTANTIATE_TEST_SUITE_P(MeaningfulTestParameters, PrimeTableTest,
  136. Combine(Bool(), Values(1, 10)));
  137. } // namespace