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