text: // Copyright 2008 Google Inc.
  // All Rights Reserved.
  //
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  //
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  // notice, this list of conditions and the following disclaimer.
  //     * Redistributions in binary form must reproduce the above
  // copyright notice, this list of conditions and the following disclaimer
  // in the documentation and/or other materials provided with the
  // distribution.
  //     * Neither the name of Google Inc. nor the names of its
  // contributors may be used to endorse or promote products derived from
  // this software without specific prior written permission.
  //
  // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  
  
  // This sample shows how to test common properties of multiple
  // implementations of the same interface (aka interface tests).
  
  // The interface and its implementations are in this header.
  #include "prime_tables.h"
  
  #include "gtest/gtest.h"
  namespace {
  // First, we define some factory functions for creating instances of
  // the implementations.  You may be able to skip this step if all your
  // implementations can be constructed the same way.
  
  template <class T>
  PrimeTable* CreatePrimeTable();
  
  template <>
  PrimeTable* CreatePrimeTable<OnTheFlyPrimeTable>() {
    return new OnTheFlyPrimeTable;
  }
  
  template <>
  PrimeTable* CreatePrimeTable<PreCalculatedPrimeTable>() {
    return new PreCalculatedPrimeTable(10000);
  }
  
  // Then we define a test fixture class template.
  template <class T>
  class PrimeTableTest : public testing::Test {
   protected:
    // The ctor calls the factory function to create a prime table
    // implemented by T.
    PrimeTableTest() : table_(CreatePrimeTable<T>()) {}
  
    ~PrimeTableTest() override { delete table_; }
  
    // Note that we test an implementation via the base interface
    // instead of the actual implementation class.  This is important
    // for keeping the tests close to the real world scenario, where the
    // implementation is invoked via the base interface.  It avoids
    // got-yas where the implementation class has a method that shadows
    // a method with the same name (but slightly different argument
    // types) in the base interface, for example.
    PrimeTable* const table_;
  };
  
  #if GTEST_HAS_TYPED_TEST
  
  using testing::Types;
  
  // Google Test offers two ways for reusing tests for different types.
  // The first is called "typed tests".  You should use it if you
  // already know *all* the types you are gonna exercise when you write
  // the tests.
  
  // To write a typed test case, first use
  //
  //   TYPED_TEST_CASE(TestCaseName, TypeList);
  //
  // to declare it and specify the type parameters.  As with TEST_F,
  // TestCaseName must match the test fixture name.
  
  // The list of types we want to test.
  typedef Types<OnTheFlyPrimeTable, PreCalculatedPrimeTable> Implementations;
  
  TYPED_TEST_CASE(PrimeTableTest, Implementations);
  
  // Then use TYPED_TEST(TestCaseName, TestName) to define a typed test,
  // similar to TEST_F.
  TYPED_TEST(PrimeTableTest, ReturnsFalseForNonPrimes) {
    // Inside the test body, you can refer to the type parameter by
    // TypeParam, and refer to the fixture class by TestFixture.  We
    // don't need them in this example.
  
    // Since we are in the template world, C++ requires explicitly
    // writing 'this->' when referring to members of the fixture class.
    // This is something you have to learn to live with.
    EXPECT_FALSE(this->table_->IsPrime(-5));
    EXPECT_FALSE(this->table_->IsPrime(0));
    EXPECT_FALSE(this->table_->IsPrime(1));
    EXPECT_FALSE(this->table_->IsPrime(4));
    EXPECT_FALSE(this->table_->IsPrime(6));
    EXPECT_FALSE(this->table_->IsPrime(100));
  }
  
  TYPED_TEST(PrimeTableTest, ReturnsTrueForPrimes) {
    EXPECT_TRUE(this->table_->IsPrime(2));
    EXPECT_TRUE(this->table_->IsPrime(3));
    EXPECT_TRUE(this->table_->IsPrime(5));
    EXPECT_TRUE(this->table_->IsPrime(7));
    EXPECT_TRUE(this->table_->IsPrime(11));
    EXPECT_TRUE(this->table_->IsPrime(131));
  }
  
  TYPED_TEST(PrimeTableTest, CanGetNextPrime) {
    EXPECT_EQ(2, this->table_->GetNextPrime(0));
    EXPECT_EQ(3, this->table_->GetNextPrime(2));
    EXPECT_EQ(5, this->table_->GetNextPrime(3));
    EXPECT_EQ(7, this->table_->GetNextPrime(5));
    EXPECT_EQ(11, this->table_->GetNextPrime(7));
    EXPECT_EQ(131, this->table_->GetNextPrime(128));
  }
  
  // That's it!  Google Test will repeat each TYPED_TEST for each type
  // in the type list specified in TYPED_TEST_CASE.  Sit back and be
  // happy that you don't have to define them multiple times.
  
  #endif  // GTEST_HAS_TYPED_TEST
  
  #if GTEST_HAS_TYPED_TEST_P
  
  using testing::Types;
  
  // Sometimes, however, you don't yet know all the types that you want
  // to test when you write the tests.  For example, if you are the
  // author of an interface and expect other people to implement it, you
  // might want to write a set of tests to make sure each implementation
  // conforms to some basic requirements, but you don't know what
  // implementations will be written in the future.
  //
  // How can you write the tests without committing to the type
  // parameters?  That's what "type-parameterized tests" can do for you.
  // It is a bit more involved than typed tests, but in return you get a
  // test pattern that can be reused in many contexts, which is a big
  // win.  Here's how you do it:
  
  // First, define a test fixture class template.  Here we just reuse
  // the PrimeTableTest fixture defined earlier:
  
  template <class T>
  class PrimeTableTest2 : public PrimeTableTest<T> {
  };
  
  // Then, declare the test case.  The argument is the name of the test
  // fixture, and also the name of the test case (as usual).  The _P
  // suffix is for "parameterized" or "pattern".
  TYPED_TEST_CASE_P(PrimeTableTest2);
  
  // Next, use TYPED_TEST_P(TestCaseName, TestName) to define a test,
  // similar to what you do with TEST_F.
  TYPED_TEST_P(PrimeTableTest2, ReturnsFalseForNonPrimes) {
    EXPECT_FALSE(this->table_->IsPrime(-5));
    EXPECT_FALSE(this->table_->IsPrime(0));
    EXPECT_FALSE(this->table_->IsPrime(1));
    EXPECT_FALSE(this->table_->IsPrime(4));
    EXPECT_FALSE(this->table_->IsPrime(6));
    EXPECT_FALSE(this->table_->IsPrime(100));
  }
  
  TYPED_TEST_P(PrimeTableTest2, ReturnsTrueForPrimes) {
    EXPECT_TRUE(this->table_->IsPrime(2));
    EXPECT_TRUE(this->table_->IsPrime(3));
    EXPECT_TRUE(this->table_->IsPrime(5));
    EXPECT_TRUE(this->table_->IsPrime(7));
    EXPECT_TRUE(this->table_->IsPrime(11));
    EXPECT_TRUE(this->table_->IsPrime(131));
  }
  
  TYPED_TEST_P(PrimeTableTest2, CanGetNextPrime) {
    EXPECT_EQ(2, this->table_->GetNextPrime(0));
    EXPECT_EQ(3, this->table_->GetNextPrime(2));
    EXPECT_EQ(5, this->table_->GetNextPrime(3));
    EXPECT_EQ(7, this->table_->GetNextPrime(5));
    EXPECT_EQ(11, this->table_->GetNextPrime(7));
    EXPECT_EQ(131, this->table_->GetNextPrime(128));
  }
  
  // Type-parameterized tests involve one extra step: you have to
  // enumerate the tests you defined:
  REGISTER_TYPED_TEST_CASE_P(
      PrimeTableTest2,  // The first argument is the test case name.
      // The rest of the arguments are the test names.
      ReturnsFalseForNonPrimes, ReturnsTrueForPrimes, CanGetNextPrime);
  
  // At this point the test pattern is done.  However, you don't have
  // any real test yet as you haven't said which types you want to run
  // the tests with.
  
  // To turn the abstract test pattern into real tests, you instantiate
  // it with a list of types.  Usually the test pattern will be defined
  // in a .h file, and anyone can #include and instantiate it.  You can
  // even instantiate it more than once in the same program.  To tell
  // different instances apart, you give each of them a name, which will
  // become part of the test case name and can be used in test filters.
  
  // The list of types we want to test.  Note that it doesn't have to be
  // defined at the time we write the TYPED_TEST_P()s.
  typedef Types<OnTheFlyPrimeTable, PreCalculatedPrimeTable>
      PrimeTableImplementations;
  INSTANTIATE_TYPED_TEST_CASE_P(OnTheFlyAndPreCalculated,    // Instance name
                                PrimeTableTest2,             // Test case name
                                PrimeTableImplementations);  // Type list
  
  #endif  // GTEST_HAS_TYPED_TEST_P
  }  // namespace
  