utils/tests.h

#ifndef WREPORT_TESTS_H
#define WREPORT_TESTS_H

#include <cstdint>
#include <exception>
#include <filesystem>
#include <functional>
#include <sstream>
#include <string>
#include <vector>

namespace wreport::tests {
struct LocationInfo;
} // namespace wreport::tests

/*
 * These global arguments will be shadowed by local variables in functions that
 * implement tests.
 *
 * They are here to act as default root nodes to fulfill method signatures when
 * tests are called from outside other tests.
 */
extern const wreport::tests::LocationInfo wreport_test_location_info;

namespace wreport::tests {

struct LocationInfo : public std::stringstream
{
    LocationInfo() {}

    std::ostream& operator()();
};

struct TestStackFrame
{
    const char* file;
    int line;
    const char* call;
    std::string local_info;

    TestStackFrame(const char* file_, int line_, const char* call_)
        : file(file_), line(line_), call(call_)
    {
    }

    TestStackFrame(const char* file_, int line_, const char* call_,
                   const LocationInfo& local_info_)
        : file(file_), line(line_), call(call_), local_info(local_info_.str())
    {
    }

    std::string format() const;

    void format(std::ostream& out) const;
};

struct TestStack : public std::vector<TestStackFrame>
{
    using vector::vector;

    std::string backtrace() const;

    void backtrace(std::ostream& out) const;
};

struct TestFailed : public std::exception
{
    std::string message;
    TestStack stack;

    explicit TestFailed(const std::exception& e);

    template <typename... Args>
    TestFailed(const std::exception& e, Args&&... args) : TestFailed(e)
    {
        add_stack_info(std::forward<Args>(args)...);
    }

    explicit TestFailed(const std::string& message_) : message(message_) {}

    template <typename... Args>
    TestFailed(const std::string& message_, Args&&... args)
        : TestFailed(message_)
    {
        add_stack_info(std::forward<Args>(args)...);
    }

    const char* what() const noexcept override { return message.c_str(); }

    template <typename... Args> void add_stack_info(Args&&... args)
    {
        stack.emplace_back(std::forward<Args>(args)...);
    }
};

struct TestSkipped : public std::exception
{
    std::string reason;

    TestSkipped();
    explicit TestSkipped(const std::string& reason);
};

#define WREPORT_TEST_INFO(name)                                                 \
    wreport::tests::LocationInfo wreport_test_location_info;                     \
    wreport::tests::LocationInfo& name = wreport_test_location_info

template <typename A> void assert_true(const A& actual)
{
    if (actual)
        return;
    std::stringstream ss;
    ss << "actual value " << actual << " is not true";
    throw TestFailed(ss.str());
}

[[noreturn]] void assert_true(std::nullptr_t actual);

template <typename A> void assert_false(const A& actual)
{
    if (!actual)
        return;
    std::stringstream ss;
    ss << "actual value " << actual << " is not false";
    throw TestFailed(ss.str());
}

void assert_false(std::nullptr_t actual);

template <typename LIST>
static inline void _format_list(std::ostream& o, const LIST& list)
{
    bool first = true;
    o << "[";
    for (const auto& v : list)
    {
        if (first)
            first = false;
        else
            o << ", ";
        o << v;
    }
    o << "]";
}

template <typename T>
void assert_equal(const std::vector<T>& actual, const std::vector<T>& expected)
{
    if (actual == expected)
        return;
    std::stringstream ss;
    ss << "value ";
    _format_list(ss, actual);
    ss << " is different than the expected ";
    _format_list(ss, expected);
    throw TestFailed(ss.str());
}

template <typename T>
void assert_equal(const std::vector<T>& actual,
                  const std::initializer_list<T>& expected)
{
    if (actual == expected)
        return;
    std::stringstream ss;
    ss << "value ";
    _format_list(ss, actual);
    ss << " is different than the expected ";
    _format_list(ss, expected);
    throw TestFailed(ss.str());
}

template <typename A, typename E>
void assert_equal(const A& actual, const E& expected)
{
    if (actual == expected)
        return;
    std::stringstream ss;
    ss << "value '" << actual << "' is different than the expected '"
       << expected << "'";
    throw TestFailed(ss.str());
}

template <typename A, typename E>
void assert_not_equal(const A& actual, const E& expected)
{
    if (actual != expected)
        return;
    std::stringstream ss;
    ss << "value '" << actual << "' is not different than the expected '"
       << expected << "'";
    throw TestFailed(ss.str());
}

template <typename A, typename E>
void assert_less(const A& actual, const E& expected)
{
    if (actual < expected)
        return;
    std::stringstream ss;
    ss << "value '" << actual << "' is not less than the expected '" << expected
       << "'";
    throw TestFailed(ss.str());
}

template <typename A, typename E>
void assert_less_equal(const A& actual, const E& expected)
{
    if (actual <= expected)
        return;
    std::stringstream ss;
    ss << "value '" << actual
       << "' is not less than or equals to the expected '" << expected << "'";
    throw TestFailed(ss.str());
}

template <typename A, typename E>
void assert_greater(const A& actual, const E& expected)
{
    if (actual > expected)
        return;
    std::stringstream ss;
    ss << "value '" << actual << "' is not greater than the expected '"
       << expected << "'";
    throw TestFailed(ss.str());
}

template <typename A, typename E>
void assert_greater_equal(const A& actual, const E& expected)
{
    if (actual >= expected)
        return;
    std::stringstream ss;
    ss << "value '" << actual
       << "' is not greater than or equals to the expected '" << expected
       << "'";
    throw TestFailed(ss.str());
}

void assert_startswith(const std::string& actual, const std::string& expected);

void assert_endswith(const std::string& actual, const std::string& expected);

void assert_contains(const std::string& actual, const std::string& expected);

void assert_not_contains(const std::string& actual,
                         const std::string& expected);

void assert_re_matches(const std::string& actual, const std::string& expected);

void assert_not_re_matches(const std::string& actual,
                           const std::string& expected);

template <class A> struct Actual
{
    A _actual;
    Actual(const A& actual) : _actual(actual) {}
    Actual(const Actual&)            = default;
    Actual(Actual&&)                 = default;
    ~Actual()                        = default;
    Actual& operator=(const Actual&) = delete;
    Actual& operator=(Actual&&)      = delete;

    void istrue() const { assert_true(_actual); }
    void isfalse() const { assert_false(_actual); }
    template <typename E> void operator==(const E& expected) const
    {
        assert_equal(_actual, expected);
    }
    template <typename E> void operator!=(const E& expected) const
    {
        assert_not_equal(_actual, expected);
    }
    template <typename E> void operator<(const E& expected) const
    {
        return assert_less(_actual, expected);
    }
    template <typename E> void operator<=(const E& expected) const
    {
        return assert_less_equal(_actual, expected);
    }
    template <typename E> void operator>(const E& expected) const
    {
        return assert_greater(_actual, expected);
    }
    template <typename E> void operator>=(const E& expected) const
    {
        return assert_greater_equal(_actual, expected);
    }
};

template <typename T> inline Actual<int> actual_int(const T& value)
{
    return Actual<int>(value);
}
template <typename T> inline Actual<unsigned> actual_unsigned(const T& value)
{
    return Actual<unsigned>(value);
}
template <typename T> inline Actual<double> actual_double(const T& value)
{
    return Actual<double>(value);
}

struct ActualCString
{
    const char* _actual;
    ActualCString(const char* s) : _actual(s) {}

    void istrue() const { return assert_true(_actual); }
    void isfalse() const { return assert_false(_actual); }
    void operator==(const char* expected) const;
    void operator==(const std::string& expected) const;
    void operator!=(const char* expected) const;
    void operator!=(const std::string& expected) const;
    void operator<(const std::string& expected) const;
    void operator<=(const std::string& expected) const;
    void operator>(const std::string& expected) const;
    void operator>=(const std::string& expected) const;
    void startswith(const std::string& expected) const;
    void endswith(const std::string& expected) const;
    void contains(const std::string& expected) const;
    void not_contains(const std::string& expected) const;
    void matches(const std::string& re) const;
    void not_matches(const std::string& re) const;
};

struct ActualStdString : public Actual<std::string>
{
    explicit ActualStdString(const std::string& s) : Actual<std::string>(s) {}

    using Actual<std::string>::operator==;
    void operator==(const std::vector<uint8_t>& expected) const;
    using Actual<std::string>::operator!=;
    void operator!=(const std::vector<uint8_t>& expected) const;
    void startswith(const std::string& expected) const;
    void endswith(const std::string& expected) const;
    void contains(const std::string& expected) const;
    void not_contains(const std::string& expected) const;
    void matches(const std::string& re) const;
    void not_matches(const std::string& re) const;
};

struct ActualPath : public Actual<std::filesystem::path>
{
    explicit ActualPath(const std::filesystem::path& p)
        : Actual<std::filesystem::path>(p)
    {
    }

    using Actual<std::filesystem::path>::operator==;
    using Actual<std::filesystem::path>::operator!=;

    // Check if the normalized paths match
    void is(const std::filesystem::path& expected) const;
    [[deprecated("Use path_startswith")]] void
    startswith(const std::string& data) const;

    void path_startswith(const std::filesystem::path& expected) const;
    void path_endswith(const std::filesystem::path& expected) const;
    void path_contains(const std::filesystem::path& expected) const;
    void path_not_contains(const std::filesystem::path& expected) const;

    void exists() const;
    void not_exists() const;
    void empty() const;
    void not_empty() const;

    void contents_startwith(const std::string& data) const;
    void contents_equal(const std::string& data) const;
    void contents_equal(const std::vector<uint8_t>& data) const;
    void contents_equal(const std::initializer_list<std::string>& lines) const;
    void contents_match(const std::string& data_re) const;
    void
    contents_match(const std::initializer_list<std::string>& lines_re) const;
};

struct ActualDouble : public Actual<double>
{
    using Actual::Actual;

    void almost_equal(double expected, unsigned places) const;
    void not_almost_equal(double expected, unsigned places) const;
};

template <typename A> inline Actual<A> actual(const A& actual)
{
    return Actual<A>(actual);
}
inline ActualCString actual(const char* actual)
{
    return ActualCString(actual);
}
inline ActualCString actual(char* actual) { return ActualCString(actual); }
inline ActualStdString actual(const std::string& actual)
{
    return ActualStdString(actual);
}
inline ActualStdString actual(const std::vector<uint8_t>& actual)
{
    return ActualStdString(std::string(actual.begin(), actual.end()));
}
inline ActualPath actual(const std::filesystem::path& actual)
{
    return ActualPath(actual);
}
inline ActualDouble actual(double actual) { return ActualDouble(actual); }

struct ActualFunction : public Actual<std::function<void()>>
{
    using Actual::Actual;

    void throws(const std::string& what_match) const;
};

inline ActualFunction actual_function(std::function<void()> actual)
{
    return ActualFunction(actual);
}

inline ActualPath actual_path(const char* pathname)
{
    return ActualPath(pathname);
}
inline ActualPath actual_path(const std::string& pathname)
{
    return ActualPath(pathname);
}
inline ActualPath actual_file(const char* pathname)
{
    return ActualPath(pathname);
}
inline ActualPath actual_file(const std::string& pathname)
{
    return ActualPath(pathname);
}

template <typename T> struct ActualVector : public Actual<std::vector<T>>
{
    explicit ActualVector(const std::vector<T>& v) : Actual<std::vector<T>>(v)
    {
    }

    void _print_vector(std::ostream& o, const std::vector<T>& value) const
    {
        o << "[";
        bool first = true;
        for (const auto& el : value)
        {
            if (first)
                first = false;
            else
                o << ", ";
            o << el;
        }
        o << "]";
    }

    void operator==(const std::vector<T>& expected)
    {
        if (expected == this->_actual)
            return;
        std::stringstream ss;
        ss << "Vector ";
        _print_vector(ss, this->_actual);
        ss << " is not the same as expected ";
        _print_vector(ss, expected);
        throw TestFailed(ss.str());
    }

    void operator!=(const std::vector<T>& expected)
    {
        if (expected != this->_actual)
            return;
        std::stringstream ss;
        ss << "Vector ";
        _print_vector(ss, this->_actual);
        ss << " unexpectedly matches the value provided";
        throw TestFailed(ss.str());
    }
};

template <typename T>
inline ActualVector<T> actual(const std::vector<T>& actual)
{
    return ActualVector(actual);
}

#define wassert(...)                                                           \
    do                                                                         \
    {                                                                          \
        try                                                                    \
        {                                                                      \
            __VA_ARGS__;                                                       \
        }                                                                      \
        catch (wreport::tests::TestFailed & e1)                                 \
        {                                                                      \
            e1.add_stack_info(__FILE__, __LINE__, #__VA_ARGS__,                \
                              wreport_test_location_info);                      \
            throw;                                                             \
        }                                                                      \
        catch (std::exception & e2)                                            \
        {                                                                      \
            throw wreport::tests::TestFailed(e2, __FILE__, __LINE__,            \
                                            #__VA_ARGS__,                      \
                                            wreport_test_location_info);        \
        }                                                                      \
    } while (0)

#define wassert_true(...) wassert(actual(__VA_ARGS__).istrue())

#define wassert_false(...) wassert(actual(__VA_ARGS__).isfalse())

#define wassert_throws(exc, ...)                                               \
    [&]() {                                                                    \
        try                                                                    \
        {                                                                      \
            __VA_ARGS__;                                                       \
            wfail_test(#__VA_ARGS__ " did not throw " #exc);                   \
        }                                                                      \
        catch (TestFailed & e1)                                                \
        {                                                                      \
            throw;                                                             \
        }                                                                      \
        catch (exc & e2)                                                       \
        {                                                                      \
            return e2;                                                         \
        }                                                                      \
        catch (std::exception & e3)                                            \
        {                                                                      \
            std::string msg(#__VA_ARGS__ " did not throw " #exc                \
                                         " but threw ");                       \
            msg += typeid(e3).name();                                          \
            msg += " instead";                                                 \
            wfail_test(msg);                                                   \
        }                                                                      \
    }()

#define wcallchecked(func)                                                     \
    [&]() {                                                                    \
        try                                                                    \
        {                                                                      \
            return func;                                                       \
        }                                                                      \
        catch (wreport::tests::TestFailed & e)                                  \
        {                                                                      \
            e.add_stack_info(__FILE__, __LINE__, #func,                        \
                             wreport_test_location_info);                       \
            throw;                                                             \
        }                                                                      \
        catch (std::exception & e)                                             \
        {                                                                      \
            throw wreport::tests::TestFailed(e, __FILE__, __LINE__, #func,      \
                                            wreport_test_location_info);        \
        }                                                                      \
    }()

#define wfail_test(msg) wassert(throw wreport::tests::TestFailed((msg)))

struct TestCase;
struct TestController;
struct TestRegistry;
struct TestCaseResult;
struct TestMethod;
struct TestMethodResult;

struct TestMethod
{
    std::string name;

    std::string doc;

    std::function<void()> test_function;

    TestMethod(const std::string& name_) : name(name_), test_function() {}

    TestMethod(const std::string& name_, std::function<void()> test_function_)
        : name(name_), test_function(test_function_)
    {
    }
};

struct TestCase
{
    std::string name;

    std::vector<TestMethod> methods;

    bool tests_registered = false;

    TestCase(const std::string& name);
    virtual ~TestCase() {}

    void register_tests_once();

    virtual void register_tests() = 0;

    virtual void setup() {}

    virtual void teardown() {}

    virtual void test_setup() {}

    virtual void test_teardown() {}

    virtual void method_setup(TestMethodResult&) { test_setup(); }

    virtual void method_teardown(TestMethodResult&) { test_teardown(); }

    virtual TestCaseResult run_tests(TestController& controller);

    virtual TestMethodResult run_test(TestController& controller,
                                      TestMethod& method);

    TestMethod& add_method(const std::string& name_)
    {
        methods.emplace_back(name_);
        return methods.back();
    }

    template <typename... Args>
    TestMethod& add_method(const std::string& name_,
                           std::function<void()> test_function)
    {
        methods.emplace_back(name_, test_function);
        return methods.back();
    }

    template <typename... Args>
    TestMethod& add_method(const std::string& name_, const std::string& doc,
                           std::function<void()> test_function)
    {
        methods.emplace_back(name_, test_function);
        methods.back().doc = doc;
        return methods.back();
    }
};

struct Fixture
{
    // Called before each test
    void test_setup() {}

    // Called after each test
    void test_teardown() {}
};

template <typename Fixture, typename... Args>
static inline Fixture* fixture_factory(Args... args)
{
    return new Fixture(args...);
}

template <typename FIXTURE> class FixtureTestCase : public TestCase
{
public:
    typedef FIXTURE Fixture;

    Fixture* fixture = nullptr;
    std::function<Fixture*()> make_fixture;

    template <typename... Args>
    FixtureTestCase(const std::string& name_, Args... args) : TestCase(name_)
    {
        make_fixture = std::bind(fixture_factory<FIXTURE, Args...>, args...);
    }
    FixtureTestCase(const FixtureTestCase&)            = delete;
    FixtureTestCase(FixtureTestCase&&)                 = delete;
    FixtureTestCase& operator=(const FixtureTestCase&) = delete;
    FixtureTestCase& operator=(FixtureTestCase&)       = delete;

    void setup() override
    {
        TestCase::setup();
        fixture = make_fixture();
    }

    void teardown() override
    {
        delete fixture;
        fixture = nullptr;
        TestCase::teardown();
    }

    void method_setup(TestMethodResult& mr) override
    {
        TestCase::method_setup(mr);
        if (fixture)
            fixture->test_setup();
    }

    void method_teardown(TestMethodResult& mr) override
    {
        if (fixture)
            fixture->test_teardown();
        TestCase::method_teardown(mr);
    }

    template <typename... Args>
    TestMethod& add_method(const std::string& name_,
                           std::function<void(FIXTURE&)> test_function)
    {
        return TestCase::add_method(name_, [=]() { test_function(*fixture); });
    }

    template <typename... Args>
    TestMethod& add_method(const std::string& name_, const std::string& doc,
                           std::function<void(FIXTURE&)> test_function)
    {
        return TestCase::add_method(name_, doc,
                                    [=]() { test_function(*fixture); });
    }
};

} // namespace wreport::tests
#endif