gtest-param-util.h

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// Copyright 2008 Google Inc.
// All Rights Reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
//     * Redistributions of source code must retain the above copyright
// 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.
//
// Author: vladl@google.com (Vlad Losev)

// Type and function utilities for implementing parameterized tests.

#ifndef GTEST_INCLUDE_GTEST_INTERNAL_GTEST_PARAM_UTIL_H_
#define GTEST_INCLUDE_GTEST_INTERNAL_GTEST_PARAM_UTIL_H_

#include <iterator>
#include <utility>
#include <vector>

// scripts/fuse_gtest.py depends on gtest's own header being #included
// *unconditionally*.  Therefore these #includes cannot be moved
// inside #if GTEST_HAS_PARAM_TEST.
#include "gtest/internal/gtest-internal.h"
#include "gtest/internal/gtest-linked_ptr.h"
#include "gtest/internal/gtest-port.h"
#include "gtest/gtest-printers.h"

#if GTEST_HAS_PARAM_TEST

namespace testing {
namespace internal {

// INTERNAL IMPLEMENTATION - DO NOT USE IN USER CODE.
//
// Outputs a message explaining invalid registration of different
// fixture class for the same test case. This may happen when
// TEST_P macro is used to define two tests with the same name
// but in different namespaces.
GTEST_API_ void ReportInvalidTestCaseType(const char* test_case_name,
                                          const char* file, int line);

template <typename> class ParamGeneratorInterface;
template <typename> class ParamGenerator;

// Interface for iterating over elements provided by an implementation
// of ParamGeneratorInterface<T>.
template <typename T>
class ParamIteratorInterface {
 public:
  virtual ~ParamIteratorInterface() {}
  // A pointer to the base generator instance.
  // Used only for the purposes of iterator comparison
  // to make sure that two iterators belong to the same generator.
  virtual const ParamGeneratorInterface<T>* BaseGenerator() const = 0;
  // Advances iterator to point to the next element
  // provided by the generator. The caller is responsible
  // for not calling Advance() on an iterator equal to
  // BaseGenerator()->End().
  virtual void Advance() = 0;
  // Clones the iterator object. Used for implementing copy semantics
  // of ParamIterator<T>.
  virtual ParamIteratorInterface* Clone() const = 0;
  // Dereferences the current iterator and provides (read-only) access
  // to the pointed value. It is the caller's responsibility not to call
  // Current() on an iterator equal to BaseGenerator()->End().
  // Used for implementing ParamGenerator<T>::operator*().
  virtual const T* Current() const = 0;
  // Determines whether the given iterator and other point to the same
  // element in the sequence generated by the generator.
  // Used for implementing ParamGenerator<T>::operator==().
  virtual bool Equals(const ParamIteratorInterface& other) const = 0;
};

// Class iterating over elements provided by an implementation of
// ParamGeneratorInterface<T>. It wraps ParamIteratorInterface<T>
// and implements the const forward iterator concept.
template <typename T>
class ParamIterator {
 public:
  typedef T value_type;
  typedef const T& reference;
  typedef ptrdiff_t difference_type;

  // ParamIterator assumes ownership of the impl_ pointer.
  ParamIterator(const ParamIterator& other) : impl_(other.impl_->Clone()) {}
  ParamIterator& operator=(const ParamIterator& other) {
    if (this != &other)
      impl_.reset(other.impl_->Clone());
    return *this;
  }

  const T& operator*() const { return *impl_->Current(); }
  const T* operator->() const { return impl_->Current(); }
  // Prefix version of operator++.
  ParamIterator& operator++() {
    impl_->Advance();
    return *this;
  }
  // Postfix version of operator++.
  ParamIterator operator++(int /*unused*/) {
    ParamIteratorInterface<T>* clone = impl_->Clone();
    impl_->Advance();
    return ParamIterator(clone);
  }
  bool operator==(const ParamIterator& other) const {
    return impl_.get() == other.impl_.get() || impl_->Equals(*other.impl_);
  }
  bool operator!=(const ParamIterator& other) const {
    return !(*this == other);
  }

 private:
  friend class ParamGenerator<T>;
  explicit ParamIterator(ParamIteratorInterface<T>* impl) : impl_(impl) {}
  scoped_ptr<ParamIteratorInterface<T> > impl_;
};

// ParamGeneratorInterface<T> is the binary interface to access generators
// defined in other translation units.
template <typename T>
class ParamGeneratorInterface {
 public:
  typedef T ParamType;

  virtual ~ParamGeneratorInterface() {}

  // Generator interface definition
  virtual ParamIteratorInterface<T>* Begin() const = 0;
  virtual ParamIteratorInterface<T>* End() const = 0;
};

// Wraps ParamGeneratorInterface<T> and provides general generator syntax
// compatible with the STL Container concept.
// This class implements copy initialization semantics and the contained
// ParamGeneratorInterface<T> instance is shared among all copies
// of the original object. This is possible because that instance is immutable.
template<typename T>
class ParamGenerator {
 public:
  typedef ParamIterator<T> iterator;

  explicit ParamGenerator(ParamGeneratorInterface<T>* impl) : impl_(impl) {}
  ParamGenerator(const ParamGenerator& other) : impl_(other.impl_) {}

  ParamGenerator& operator=(const ParamGenerator& other) {
    impl_ = other.impl_;
    return *this;
  }

  iterator begin() const { return iterator(impl_->Begin()); }
  iterator end() const { return iterator(impl_->End()); }

 private:
  linked_ptr<const ParamGeneratorInterface<T> > impl_;
};

// Generates values from a range of two comparable values. Can be used to
// generate sequences of user-defined types that implement operator+() and
// operator<().
// This class is used in the Range() function.
template <typename T, typename IncrementT>
class RangeGenerator : public ParamGeneratorInterface<T> {
 public:
  RangeGenerator(T begin, T end, IncrementT step)
      : begin_(begin), end_(end),
        step_(step), end_index_(CalculateEndIndex(begin, end, step)) {}
  virtual ~RangeGenerator() {}

  virtual ParamIteratorInterface<T>* Begin() const {
    return new Iterator(this, begin_, 0, step_);
  }
  virtual ParamIteratorInterface<T>* End() const {
    return new Iterator(this, end_, end_index_, step_);
  }

 private:
  class Iterator : public ParamIteratorInterface<T> {
   public:
    Iterator(const ParamGeneratorInterface<T>* base, T value, int index,
             IncrementT step)
        : base_(base), value_(value), index_(index), step_(step) {}
    virtual ~Iterator() {}

    virtual const ParamGeneratorInterface<T>* BaseGenerator() const {
      return base_;
    }
    virtual void Advance() {
      value_ = value_ + step_;
      index_++;
    }
    virtual ParamIteratorInterface<T>* Clone() const {
      return new Iterator(*this);
    }
    virtual const T* Current() const { return &value_; }
    virtual bool Equals(const ParamIteratorInterface<T>& other) const {
      // Having the same base generator guarantees that the other
      // iterator is of the same type and we can downcast.
      GTEST_CHECK_(BaseGenerator() == other.BaseGenerator())
          << "The program attempted to compare iterators "
          << "from different generators." << std::endl;
      const int other_index =
          CheckedDowncastToActualType<const Iterator>(&other)->index_;
      return index_ == other_index;
    }

   private:
    Iterator(const Iterator& other)
        : ParamIteratorInterface<T>(),
          base_(other.base_), value_(other.value_), index_(other.index_),
          step_(other.step_) {}

    // No implementation - assignment is unsupported.
    void operator=(const Iterator& other);

    const ParamGeneratorInterface<T>* const base_;
    T value_;
    int index_;
    const IncrementT step_;
  };  // class RangeGenerator::Iterator

  static int CalculateEndIndex(const T& begin,
                               const T& end,
                               const IncrementT& step) {
    int end_index = 0;
    for (T i = begin; i < end; i = i + step)
      end_index++;
    return end_index;
  }

  // No implementation - assignment is unsupported.
  void operator=(const RangeGenerator& other);

  const T begin_;
  const T end_;
  const IncrementT step_;
  // The index for the end() iterator. All the elements in the generated
  // sequence are indexed (0-based) to aid iterator comparison.
  const int end_index_;
};  // class RangeGenerator


// Generates values from a pair of STL-style iterators. Used in the
// ValuesIn() function. The elements are copied from the source range
// since the source can be located on the stack, and the generator
// is likely to persist beyond that stack frame.
template <typename T>
class ValuesInIteratorRangeGenerator : public ParamGeneratorInterface<T> {
 public:
  template <typename ForwardIterator>
  ValuesInIteratorRangeGenerator(ForwardIterator begin, ForwardIterator end)
      : container_(begin, end) {}
  virtual ~ValuesInIteratorRangeGenerator() {}

  virtual ParamIteratorInterface<T>* Begin() const {
    return new Iterator(this, container_.begin());
  }
  virtual ParamIteratorInterface<T>* End() const {
    return new Iterator(this, container_.end());
  }

 private:
  typedef typename ::std::vector<T> ContainerType;

  class Iterator : public ParamIteratorInterface<T> {
   public:
    Iterator(const ParamGeneratorInterface<T>* base,
             typename ContainerType::const_iterator iterator)
        : base_(base), iterator_(iterator) {}
    virtual ~Iterator() {}

    virtual const ParamGeneratorInterface<T>* BaseGenerator() const {
      return base_;
    }
    virtual void Advance() {
      ++iterator_;
      value_.reset();
    }
    virtual ParamIteratorInterface<T>* Clone() const {
      return new Iterator(*this);
    }
    // We need to use cached value referenced by iterator_ because *iterator_
    // can return a temporary object (and of type other then T), so just
    // having "return &*iterator_;" doesn't work.
    // value_ is updated here and not in Advance() because Advance()
    // can advance iterator_ beyond the end of the range, and we cannot
    // detect that fact. The client code, on the other hand, is
    // responsible for not calling Current() on an out-of-range iterator.
    virtual const T* Current() const {
      if (value_.get() == NULL)
        value_.reset(new T(*iterator_));
      return value_.get();
    }
    virtual bool Equals(const ParamIteratorInterface<T>& other) const {
      // Having the same base generator guarantees that the other
      // iterator is of the same type and we can downcast.
      GTEST_CHECK_(BaseGenerator() == other.BaseGenerator())
          << "The program attempted to compare iterators "
          << "from different generators." << std::endl;
      return iterator_ ==
          CheckedDowncastToActualType<const Iterator>(&other)->iterator_;
    }

   private:
    Iterator(const Iterator& other)
          // The explicit constructor call suppresses a false warning
          // emitted by gcc when supplied with the -Wextra option.
        : ParamIteratorInterface<T>(),
          base_(other.base_),
          iterator_(other.iterator_) {}

    const ParamGeneratorInterface<T>* const base_;
    typename ContainerType::const_iterator iterator_;
    // A cached value of *iterator_. We keep it here to allow access by
    // pointer in the wrapping iterator's operator->().
    // value_ needs to be mutable to be accessed in Current().
    // Use of scoped_ptr helps manage cached value's lifetime,
    // which is bound by the lifespan of the iterator itself.
    mutable scoped_ptr<const T> value_;
  };  // class ValuesInIteratorRangeGenerator::Iterator

  // No implementation - assignment is unsupported.
  void operator=(const ValuesInIteratorRangeGenerator& other);

  const ContainerType container_;
};  // class ValuesInIteratorRangeGenerator

// INTERNAL IMPLEMENTATION - DO NOT USE IN USER CODE.
//
// Stores a parameter value and later creates tests parameterized with that
// value.
template <class TestClass>
class ParameterizedTestFactory : public TestFactoryBase {
 public:
  typedef typename TestClass::ParamType ParamType;
  explicit ParameterizedTestFactory(ParamType parameter) :
      parameter_(parameter) {}
  virtual Test* CreateTest() {
    TestClass::SetParam(&parameter_);
    return new TestClass();
  }

 private:
  const ParamType parameter_;

  GTEST_DISALLOW_COPY_AND_ASSIGN_(ParameterizedTestFactory);
};

// INTERNAL IMPLEMENTATION - DO NOT USE IN USER CODE.
//
// TestMetaFactoryBase is a base class for meta-factories that create
// test factories for passing into MakeAndRegisterTestInfo function.
template <class ParamType>
class TestMetaFactoryBase {
 public:
  virtual ~TestMetaFactoryBase() {}

  virtual TestFactoryBase* CreateTestFactory(ParamType parameter) = 0;
};

// INTERNAL IMPLEMENTATION - DO NOT USE IN USER CODE.
//
// TestMetaFactory creates test factories for passing into
// MakeAndRegisterTestInfo function. Since MakeAndRegisterTestInfo receives
// ownership of test factory pointer, same factory object cannot be passed
// into that method twice. But ParameterizedTestCaseInfo is going to call
// it for each Test/Parameter value combination. Thus it needs meta factory
// creator class.
template <class TestCase>
class TestMetaFactory
    : public TestMetaFactoryBase<typename TestCase::ParamType> {
 public:
  typedef typename TestCase::ParamType ParamType;

  TestMetaFactory() {}

  virtual TestFactoryBase* CreateTestFactory(ParamType parameter) {
    return new ParameterizedTestFactory<TestCase>(parameter);
  }

 private:
  GTEST_DISALLOW_COPY_AND_ASSIGN_(TestMetaFactory);
};

// INTERNAL IMPLEMENTATION - DO NOT USE IN USER CODE.
//
// ParameterizedTestCaseInfoBase is a generic interface
// to ParameterizedTestCaseInfo classes. ParameterizedTestCaseInfoBase
// accumulates test information provided by TEST_P macro invocations
// and generators provided by INSTANTIATE_TEST_CASE_P macro invocations
// and uses that information to register all resulting test instances
// in RegisterTests method. The ParameterizeTestCaseRegistry class holds
// a collection of pointers to the ParameterizedTestCaseInfo objects
// and calls RegisterTests() on each of them when asked.
class ParameterizedTestCaseInfoBase {
 public:
  virtual ~ParameterizedTestCaseInfoBase() {}

  // Base part of test case name for display purposes.
  virtual const string& GetTestCaseName() const = 0;
  // Test case id to verify identity.
  virtual TypeId GetTestCaseTypeId() const = 0;
  // UnitTest class invokes this method to register tests in this
  // test case right before running them in RUN_ALL_TESTS macro.
  // This method should not be called more then once on any single
  // instance of a ParameterizedTestCaseInfoBase derived class.
  virtual void RegisterTests() = 0;

 protected:
  ParameterizedTestCaseInfoBase() {}

 private:
  GTEST_DISALLOW_COPY_AND_ASSIGN_(ParameterizedTestCaseInfoBase);
};

// INTERNAL IMPLEMENTATION - DO NOT USE IN USER CODE.
//
// ParameterizedTestCaseInfo accumulates tests obtained from TEST_P
// macro invocations for a particular test case and generators
// obtained from INSTANTIATE_TEST_CASE_P macro invocations for that
// test case. It registers tests with all values generated by all
// generators when asked.
template <class TestCase>
class ParameterizedTestCaseInfo : public ParameterizedTestCaseInfoBase {
 public:
  // ParamType and GeneratorCreationFunc are private types but are required
  // for declarations of public methods AddTestPattern() and
  // AddTestCaseInstantiation().
  typedef typename TestCase::ParamType ParamType;
  // A function that returns an instance of appropriate generator type.
  typedef ParamGenerator<ParamType>(GeneratorCreationFunc)();

  explicit ParameterizedTestCaseInfo(const char* name)
      : test_case_name_(name) {}

  // Test case base name for display purposes.
  virtual const string& GetTestCaseName() const { return test_case_name_; }
  // Test case id to verify identity.
  virtual TypeId GetTestCaseTypeId() const { return GetTypeId<TestCase>(); }
  // TEST_P macro uses AddTestPattern() to record information
  // about a single test in a LocalTestInfo structure.
  // test_case_name is the base name of the test case (without invocation
  // prefix). test_base_name is the name of an individual test without
  // parameter index. For the test SequenceA/FooTest.DoBar/1 FooTest is
  // test case base name and DoBar is test base name.
  void AddTestPattern(const char* test_case_name,
                      const char* test_base_name,
                      TestMetaFactoryBase<ParamType>* meta_factory) {
    tests_.push_back(linked_ptr<TestInfo>(new TestInfo(test_case_name,
                                                       test_base_name,
                                                       meta_factory)));
  }
  // INSTANTIATE_TEST_CASE_P macro uses AddGenerator() to record information
  // about a generator.
  int AddTestCaseInstantiation(const string& instantiation_name,
                               GeneratorCreationFunc* func,
                               const char* /* file */,
                               int /* line */) {
    instantiations_.push_back(::std::make_pair(instantiation_name, func));
    return 0;  // Return value used only to run this method in namespace scope.
  }
  // UnitTest class invokes this method to register tests in this test case
  // test cases right before running tests in RUN_ALL_TESTS macro.
  // This method should not be called more then once on any single
  // instance of a ParameterizedTestCaseInfoBase derived class.
  // UnitTest has a guard to prevent from calling this method more then once.
  virtual void RegisterTests() {
    for (typename TestInfoContainer::iterator test_it = tests_.begin();
         test_it != tests_.end(); ++test_it) {
      linked_ptr<TestInfo> test_info = *test_it;
      for (typename InstantiationContainer::iterator gen_it =
               instantiations_.begin(); gen_it != instantiations_.end();
               ++gen_it) {
        const string& instantiation_name = gen_it->first;
        ParamGenerator<ParamType> generator((*gen_it->second)());

        string test_case_name;
        if ( !instantiation_name.empty() )
          test_case_name = instantiation_name + "/";
        test_case_name += test_info->test_case_base_name;

        int i = 0;
        for (typename ParamGenerator<ParamType>::iterator param_it =
                 generator.begin();
             param_it != generator.end(); ++param_it, ++i) {
          Message test_name_stream;
          test_name_stream << test_info->test_base_name << "/" << i;
          MakeAndRegisterTestInfo(
              test_case_name.c_str(),
              test_name_stream.GetString().c_str(),
              NULL,  // No type parameter.
              PrintToString(*param_it).c_str(),
              GetTestCaseTypeId(),
              TestCase::SetUpTestCase,
              TestCase::TearDownTestCase,
              test_info->test_meta_factory->CreateTestFactory(*param_it));
        }  // for param_it
      }  // for gen_it
    }  // for test_it
  }  // RegisterTests

 private:
  // LocalTestInfo structure keeps information about a single test registered
  // with TEST_P macro.
  struct TestInfo {
    TestInfo(const char* a_test_case_base_name,
             const char* a_test_base_name,
             TestMetaFactoryBase<ParamType>* a_test_meta_factory) :
        test_case_base_name(a_test_case_base_name),
        test_base_name(a_test_base_name),
        test_meta_factory(a_test_meta_factory) {}

    const string test_case_base_name;
    const string test_base_name;
    const scoped_ptr<TestMetaFactoryBase<ParamType> > test_meta_factory;
  };
  typedef ::std::vector<linked_ptr<TestInfo> > TestInfoContainer;
  // Keeps pairs of <Instantiation name, Sequence generator creation function>
  // received from INSTANTIATE_TEST_CASE_P macros.
  typedef ::std::vector<std::pair<string, GeneratorCreationFunc*> >
      InstantiationContainer;

  const string test_case_name_;
  TestInfoContainer tests_;
  InstantiationContainer instantiations_;

  GTEST_DISALLOW_COPY_AND_ASSIGN_(ParameterizedTestCaseInfo);
};  // class ParameterizedTestCaseInfo

// INTERNAL IMPLEMENTATION - DO NOT USE IN USER CODE.
//
// ParameterizedTestCaseRegistry contains a map of ParameterizedTestCaseInfoBase
// classes accessed by test case names. TEST_P and INSTANTIATE_TEST_CASE_P
// macros use it to locate their corresponding ParameterizedTestCaseInfo
// descriptors.
class ParameterizedTestCaseRegistry {
 public:
  ParameterizedTestCaseRegistry() {}
  ~ParameterizedTestCaseRegistry() {
    for (TestCaseInfoContainer::iterator it = test_case_infos_.begin();
         it != test_case_infos_.end(); ++it) {
      delete *it;
    }
  }

  // Looks up or creates and returns a structure containing information about
  // tests and instantiations of a particular test case.
  template <class TestCase>
  ParameterizedTestCaseInfo<TestCase>* GetTestCasePatternHolder(
      const char* test_case_name,
      const char* file,
      int line) {
    ParameterizedTestCaseInfo<TestCase>* typed_test_info = NULL;
    for (TestCaseInfoContainer::iterator it = test_case_infos_.begin();
         it != test_case_infos_.end(); ++it) {
      if ((*it)->GetTestCaseName() == test_case_name) {
        if ((*it)->GetTestCaseTypeId() != GetTypeId<TestCase>()) {
          // Complain about incorrect usage of Google Test facilities
          // and terminate the program since we cannot guaranty correct
          // test case setup and tear-down in this case.
          ReportInvalidTestCaseType(test_case_name,  file, line);
          posix::Abort();
        } else {
          // At this point we are sure that the object we found is of the same
          // type we are looking for, so we downcast it to that type
          // without further checks.
          typed_test_info = CheckedDowncastToActualType<
              ParameterizedTestCaseInfo<TestCase> >(*it);
        }
        break;
      }
    }
    if (typed_test_info == NULL) {
      typed_test_info = new ParameterizedTestCaseInfo<TestCase>(test_case_name);
      test_case_infos_.push_back(typed_test_info);
    }
    return typed_test_info;
  }
  void RegisterTests() {
    for (TestCaseInfoContainer::iterator it = test_case_infos_.begin();
         it != test_case_infos_.end(); ++it) {
      (*it)->RegisterTests();
    }
  }

 private:
  typedef ::std::vector<ParameterizedTestCaseInfoBase*> TestCaseInfoContainer;

  TestCaseInfoContainer test_case_infos_;

  GTEST_DISALLOW_COPY_AND_ASSIGN_(ParameterizedTestCaseRegistry);
};

}  // namespace internal
}  // namespace testing

#endif  //  GTEST_HAS_PARAM_TEST

#endif  // GTEST_INCLUDE_GTEST_INTERNAL_GTEST_PARAM_UTIL_H_