Remove cycle suppression

[gromacs.git] / src / testutils / testasserts.h

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/*! \libinternal \file
 * \brief
 * Extra assertions for unit tests.
 *
 * This file provides assertion macros that extend/replace Google Test
 * assertions for:
 *  - exceptions
 *  - floating-point comparison
 *  - comparison against NULL
 *
 * \if internal
 * \todo
 * The implementation is somewhat ugly, and accesses some Google Test
 * internals.  Could be nice to clean it up a bit.
 * \endif
 *
 * \author Teemu Murtola <teemu.murtola@gmail.com>
 * \inlibraryapi
 * \ingroup module_testutils
 */
#ifndef GMX_TESTUTILS_TESTASSERTS_H
#define GMX_TESTUTILS_TESTASSERTS_H

#include <string>

#include <gtest/gtest.h>

#include "gromacs/utility/basedefinitions.h"
#include "gromacs/utility/exceptions.h"
#include "gromacs/utility/real.h"

namespace gmx
{
namespace test
{

namespace internal
{
//! \cond internal
/*! \internal
 * \brief
 * Called for an expected exception from EXPECT_THROW_GMX().
 *
 * \param[in] ex  Exception that was thrown.
 */
void processExpectedException(const std::exception &ex);
//! \endcond
}

//! \libinternal \addtogroup module_testutils
//! \{

/*! \name Assertions for exceptions
 *
 * These macros replace `(ASSERT|EXPECT)(_NO)?_THROW` from Google Test.
 * They are used exactly like the Google Test ones, but also print details of
 * any unexpected exceptions using \Gromacs-specific routines.
 * This makes it much easier to see at one glance what went wrong.
 * See Google Test documentation for details on how to use the macros.
 */
//! \{

//! \cond internal
/*! \brief
 * Internal implementation macro for exception assertations.
 *
 * \param statement          Statements to execute.
 * \param expected_exception Exception type that \p statement should throw.
 * \param fail               Function/macro to call on failure.
 *
 * The implementation is copied and adjusted from
 * include/gtest/internal/gtest-internal.h in Google Test 1.6.0.
 */
#define GMX_TEST_THROW_(statement, expected_exception, fail) \
    GTEST_AMBIGUOUS_ELSE_BLOCKER_ \
    if (::testing::AssertionResult gmx_ar = ::testing::AssertionSuccess()) { \
        bool gmx_caught_expected = false; \
        try { \
            GTEST_SUPPRESS_UNREACHABLE_CODE_WARNING_BELOW_(statement); \
        } \
        catch (expected_exception const &ex) { \
            gmx_caught_expected = true; \
            ::gmx::test::internal::processExpectedException(ex); \
        } \
        catch (std::exception const &ex) { \
            gmx_ar << "Expected: " #statement " throws an exception of type " \
            << #expected_exception ".\n  Actual: it throws a different type.\n" \
            << "Exception details:\n" << ::gmx::formatExceptionMessageToString(ex); \
            goto GTEST_CONCAT_TOKEN_(gmx_label_testthrow_, __LINE__); \
        } \
        catch (...) { \
            gmx_ar << "Expected: " #statement " throws an exception of type " \
            << #expected_exception ".\n  Actual: it throws a different type."; \
            goto GTEST_CONCAT_TOKEN_(gmx_label_testthrow_, __LINE__); \
        } \
        if (!gmx_caught_expected) { \
            gmx_ar << "Expected: " #statement " throws an exception of type " \
            << #expected_exception ".\n  Actual: it throws nothing."; \
            goto GTEST_CONCAT_TOKEN_(gmx_label_testthrow_, __LINE__); \
        } \
    } else \
        GTEST_CONCAT_TOKEN_(gmx_label_testthrow_, __LINE__) : \
            fail(gmx_ar.message())

/*! \brief
 * Internal implementation macro for exception assertations.
 *
 * \param statement          Statements to execute.
 * \param fail               Function/macro to call on failure.
 *
 * The implementation is copied and adjusted from
 * include/gtest/internal/gtest-internal.h in Google Test 1.6.0.
 */
#define GMX_TEST_NO_THROW_(statement, fail) \
    GTEST_AMBIGUOUS_ELSE_BLOCKER_ \
    if (::testing::AssertionResult gmx_ar = ::testing::AssertionSuccess()) { \
        try { \
            GTEST_SUPPRESS_UNREACHABLE_CODE_WARNING_BELOW_(statement); \
        } \
        catch (std::exception const &ex) { \
            gmx_ar << "Expected: " #statement " doesn't throw an exception.\n" \
            << "  Actual: it throws.\n" \
            << "Exception details:\n" << ::gmx::formatExceptionMessageToString(ex); \
            goto GTEST_CONCAT_TOKEN_(gmx_label_testnothrow_, __LINE__); \
        } \
        catch (...) { \
            gmx_ar << "Expected: " #statement " doesn't throw an exception.\n" \
            << "  Actual: it throws."; \
            goto GTEST_CONCAT_TOKEN_(gmx_label_testnothrow_, __LINE__); \
        } \
    } else \
        GTEST_CONCAT_TOKEN_(gmx_label_testnothrow_, __LINE__) : \
            fail(gmx_ar.message())
//! \endcond

/*! \brief
 * Asserts that a statement throws a given exception.
 *
 * \hideinitializer
 */
#define EXPECT_THROW_GMX(statement, expected_exception) \
    GMX_TEST_THROW_(statement, expected_exception, GTEST_NONFATAL_FAILURE_)
/*! \brief
 * Asserts that a statement does not throw.
 *
 * \hideinitializer
 */
#define EXPECT_NO_THROW_GMX(statement) \
    GMX_TEST_NO_THROW_(statement, GTEST_NONFATAL_FAILURE_)
/*! \brief
 * Asserts that a statement throws a given exception.
 *
 * \hideinitializer
 */
#define ASSERT_THROW_GMX(statement, expected_exception) \
    GMX_TEST_THROW_(statement, expected_exception, GTEST_FATAL_FAILURE_)
/*! \brief
 * Asserts that a statement does not throw.
 *
 * \hideinitializer
 */
#define ASSERT_NO_THROW_GMX(statement) \
    GMX_TEST_NO_THROW_(statement, GTEST_FATAL_FAILURE_)

//! \}

/*! \libinternal \brief
 * Computes and represents a floating-point difference value.
 *
 * Methods in this class do not throw, except for toString(), which may throw
 * std::bad_alloc.
 *
 * \see FloatingPointTolerance
 */
class FloatingPointDifference
{
    public:

        /*! \brief Initializes a single-precision difference.
         *
         *  \param ref    First term in difference
         *  \param value  Second term in difference
         *
         *  For absolute and ULP differences the two parameters are equivalent,
         *  since the difference is symmetric. For relative differences
         *  the first term is interpreted as the reference value, from which
         *  we extract the magnitude to compare with.
         */
        FloatingPointDifference(float ref, float value);

        /*! \brief Initializes a double-precision difference.
         *
         *  \param ref    First term in difference
         *  \param value  Second term in difference
         *
         *  For absolute and ULP differences the two parameters are equivalent,
         *  since the difference is symmetric. For relative differences
         *  the first term is interpreted as the reference value, from which
         *  we extract the magnitude to compare with.
         */
        FloatingPointDifference(double ref, double value);

        /*! \brief
         * Whether one or both of the compared values were NaN.
         *
         * If this returns `true`, other accessors return meaningless values.
         */
        bool isNaN() const;
        //! Returns the difference as an absolute number (always non-negative).
        double asAbsolute() const { return absoluteDifference_; }
        /*! \brief
         * Returns the difference as ULPs (always non-negative).
         *
         * The ULPs are calculated for the type that corresponds to the
         * constructor used to initialize the difference.
         * The ULP difference between 0.0 and -0.0 is zero.
         */
        gmx_uint64_t asUlps() const { return ulpDifference_; }
        /*! \brief
         * Whether the compared values were of different sign.
         *
         * 0.0 and -0.0 are treated as positive and negative, respectively.
         */
        bool signsDiffer() const { return bSignDifference_; }
        /*! \brief
         * Whether the difference is between single- or double-precision
         * numbers.
         */
        bool isDouble() const { return bDouble_; }
        //! Formats the difference as a string for assertion failure messages.
        std::string toString() const;

        //! Returns the magnitude of the original second term of the difference.
        double termMagnitude() const { return termMagnitude_; }

    private:

        //! Save the magnitude of the reference value for relative (i.e., not ULP) tolerance
        double       termMagnitude_;
        //! Stores the absolute difference, or NaN if one or both values were NaN.
        double       absoluteDifference_;
        gmx_uint64_t ulpDifference_;
        bool         bSignDifference_;
        /*! \brief
         * Whether the difference was computed for single or double precision.
         *
         * This sets the units for `ulpDifference_`.
         */
        bool         bDouble_;
};

/*! \libinternal \brief
 * Specifies a floating-point comparison tolerance and checks whether a
 * difference is within the tolerance.
 *
 * The related functions section lists methods that can be construct methods
 * using less parameters than the full constructor, and with more obvious
 * semantics.  These should be preferred over using the constructor directly.
 *
 * Several types of tolerances are possible:
 *  - _absolute tolerance_: difference between the values must be smaller than
 *    the given tolerance for the check to pass.
 *    Setting the absolute tolerance to zero disables the absolute tolerance
 *    check.
 *  - _relative tolerance_: the absolute difference between the numbers must
 *    be smaller than the tolerance multiplied by the first number. Setting
 *    the relative tolerance to zero disables this check.
 *  - _ULP tolerance_: ULP (units of least precision) difference between the
 *    values must be smaller than the given tolerance for the check to pass.
 *    Setting the ULP tolerance to zero requires exact match.
 *    Setting the ULP tolerance to GMX_UINT64_MAX disables the ULP check.
 *    `0.0` and `-0.0` are treated as equal for the ULP check.
 *  - _sign check_: if set, any values that are of different signs fail the
 *    check (note that this also applies to `0.0` and `-0.0`: a value with a
 *    different sign than the zero will fail the check).
 *
 * Either an absolute, relative, or ULP tolerance must always be specified.
 * If several of them are specified, then the check passes if either of the
 * tolerances is satisfied.
 *
 * Any combination of absolute, relative, and ULP tolerance can be combined with
 * the sign check.  In this case, the sign check must succeed for the check to
 * pass, even if other tolerances are satisfied.
 *
 * The tolerances can be specified separately for single and double precision
 * comparison.  Different initialization functions have different semantics on
 * how the provided tolerance values are interpreted; check their
 * documentation.
 *
 * Methods in this class do not throw, except for toString(), which may throw
 * std::bad_alloc.
 *
 * \todo
 * The factory methods that take ULP difference could be better formulated as
 * methods that take the acceptable number of incorrect bits and/or the number
 * of accurate bits.
 *
 * \see FloatingPointDifference
 */
class FloatingPointTolerance
{
    public:
        /*! \brief
         * Creates a tolerance with the specified values.
         *
         * \param[in]  singleAbsoluteTolerance
         *     Allowed absolute difference in a single-precision number.
         * \param[in]  doubleAbsoluteTolerance
         *     Allowed absolute difference in a double-precision number.
         * \param[in]  singleRelativeTolerance
         *     Allowed relative difference in a single-precision number.
         * \param[in]  doubleRelativeTolerance
         *     Allowed relative difference in a double-precision number.
         * \param[in]  singleUlpTolerance
         *     Allowed ULP difference in a single-precision number.
         * \param[in]  doubleUlpTolerance
         *     Allowed ULP difference in a double-precision number.
         * \param[in]  bSignMustMatch
         *     Whether sign mismatch fails the comparison.
         */
        FloatingPointTolerance(float        singleAbsoluteTolerance,
                               double       doubleAbsoluteTolerance,
                               float        singleRelativeTolerance,
                               double       doubleRelativeTolerance,
                               gmx_uint64_t singleUlpTolerance,
                               gmx_uint64_t doubleUlpTolerance,
                               bool         bSignMustMatch)
            : singleAbsoluteTolerance_(singleAbsoluteTolerance),
              doubleAbsoluteTolerance_(doubleAbsoluteTolerance),
              singleRelativeTolerance_(singleRelativeTolerance),
              doubleRelativeTolerance_(doubleRelativeTolerance),
              singleUlpTolerance_(singleUlpTolerance),
              doubleUlpTolerance_(doubleUlpTolerance),
              bSignMustMatch_(bSignMustMatch)
        {
        }

        /*! \brief
         * Checks whether a difference is within the specified tolerance.
         *
         * NaNs are always treated outside the tolerance.
         */
        bool isWithin(const FloatingPointDifference &difference) const;

        //! Formats the tolerance as a string for assertion failure messages.
        std::string toString(const FloatingPointDifference &difference) const;

    private:
        float        singleAbsoluteTolerance_;
        double       doubleAbsoluteTolerance_;
        float        singleRelativeTolerance_;
        double       doubleRelativeTolerance_;
        gmx_uint64_t singleUlpTolerance_;
        gmx_uint64_t doubleUlpTolerance_;
        bool         bSignMustMatch_;
};

/*! \brief
 * Creates a tolerance that only allows a specified ULP difference.
 *
 * The tolerance uses the given ULP value for both precisions, i.e., double
 * precision will have much stricter tolerance.
 *
 * \related FloatingPointTolerance
 */
static inline FloatingPointTolerance
ulpTolerance(gmx_uint64_t ulpDiff)
{
    return FloatingPointTolerance(0.0, 0.0, 0.0, 0.0, ulpDiff, ulpDiff, false);
}

/*! \brief
 * Creates a tolerance that allows a difference in two compared values that is
 * relative to the given magnitude.
 *
 * \param[in] magnitude  Magnitude of the numbers the computation operates in.
 * \param[in] tolerance  Relative tolerance permitted (e.g. 1e-4).
 *
 * In addition to setting an relative tolerance for both
 * precisions, this sets the absolute tolerance such that values close to zero
 * (in general, smaller than \p magnitude) do not fail the check if they
 * differ by less than \p tolerance evaluated at \p magnitude.  This accounts
 * for potential loss of precision for small values, and should be used when
 * accuracy of values much less than \p magnitude do not matter for
 * correctness.
 *
 * \related FloatingPointTolerance
 */
FloatingPointTolerance
    relativeToleranceAsFloatingPoint(double magnitude, double tolerance);

/*! \brief
 * Creates a tolerance that allows a precision-dependent relative difference in
 * a complex computation.
 *
 * \param[in] magnitude      Magnitude of the numbers the computation operates in.
 * \param[in] singleUlpDiff  Expected accuracy of single-precision
 *     computation (in ULPs).
 * \param[in] doubleUlpDiff  Expected accuracy of double-precision
 *     computation (in ULPs).
 *
 * This works as relativeToleranceAsUlp(), but allows setting the ULP
 * difference separately for the different precisions.  This supports
 * cases where the double-precision calculation can acceptably has a higher ULP
 * difference, but relaxing the single-precision tolerance would lead to an
 * unnecessarily loose test.
 *
 * \related FloatingPointTolerance
 */
static inline FloatingPointTolerance
relativeToleranceAsPrecisionDependentUlp(double       magnitude,
                                         gmx_uint64_t singleUlpDiff,
                                         gmx_uint64_t doubleUlpDiff)
{
    return FloatingPointTolerance(magnitude*singleUlpDiff*GMX_FLOAT_EPS,
                                  magnitude*doubleUlpDiff*GMX_DOUBLE_EPS,
                                  0.0, 0.0,
                                  singleUlpDiff, doubleUlpDiff, false);
}

/*! \brief
 * Creates a tolerance that allows a specified absolute difference.
 *
 * \related FloatingPointTolerance
 */
static inline FloatingPointTolerance
absoluteTolerance(double tolerance)
{
    return FloatingPointTolerance(tolerance, tolerance, 0.0, 0.0,
                                  GMX_UINT64_MAX, GMX_UINT64_MAX, false);
}

/*! \brief
 * Creates a tolerance that allows a relative difference in a complex
 * computation.
 *
 * \param[in] magnitude  Magnitude of the numbers the computation operates in.
 * \param[in] ulpDiff    Expected accuracy of the computation (in ULPs).
 *
 * In addition to setting the ULP tolerance as ulpTolerance(), this sets the
 * absolute tolerance such that values close to zero (in general, smaller than
 * \p magnitude) do not fail the check if they differ by less than \p ulpDiff
 * evaluated at \p magnitude.  This accounts for potential loss of precision
 * for small values, and should be used when accuracy of values much less than
 * \p magnitude do not matter for correctness.
 *
 * \related FloatingPointTolerance
 */
static inline FloatingPointTolerance
relativeToleranceAsUlp(double magnitude, gmx_uint64_t ulpDiff)
{
    return relativeToleranceAsPrecisionDependentUlp(magnitude, ulpDiff, ulpDiff);
}

namespace
{
//! Default tolerance in ULPs for two floating-point values to compare equal.
static gmx_uint64_t g_defaultUlpTolerance = 4;
}

/*! \brief
 * Returns the default tolerance for comparing `real` numbers.
 *
 * \related FloatingPointTolerance
 */
static inline FloatingPointTolerance defaultRealTolerance()
{
    return relativeToleranceAsUlp(1.0, g_defaultUlpTolerance);
}


/*! \brief
 * Returns the default tolerance for comparing single-precision numbers when
 * compared by \Gromacs built in either precision mode.
 *
 * This permits a checker compiled with any \Gromacs precision to compare
 * equal or not in the same way.
 *
 * \related FloatingPointTolerance
 */
static inline FloatingPointTolerance defaultFloatTolerance()
{
    return relativeToleranceAsPrecisionDependentUlp
               (1.0, g_defaultUlpTolerance, g_defaultUlpTolerance * (GMX_FLOAT_EPS / GMX_DOUBLE_EPS));
}

/*! \name Assertions for floating-point comparison
 *
 * These routines extend `(EXPECT|ASSERT)_(FLOAT|DOUBLE)_EQ` and
 * `(EXPECT|ASSERT)_NEAR` from Google Test to provide more flexible assertions
 * for floating-point values.
 *
 * See gmx::test::FloatingPointTolerance for the possible ways to specify the
 * tolerance, and gmx::test::FloatingPointDifference for some additional
 * details of the difference calculation.
 */
//! \{

//! \cond internal
/*! \internal \brief
 * Assertion predicate formatter for comparing two floating-point values.
 */
template <typename FloatType>
static inline ::testing::AssertionResult assertEqualWithinTolerance(
        const char *expr1, const char *expr2, const char * /*exprTolerance*/,
        FloatType value1, FloatType value2,
        const FloatingPointTolerance &tolerance)
{
    FloatingPointDifference diff(value1, value2);
    if (tolerance.isWithin(diff))
    {
        return ::testing::AssertionSuccess();
    }
    return ::testing::AssertionFailure()
           << "  Value of: " << expr2 << std::endl
           << "    Actual: " << value2 << std::endl
           << "  Expected: " << expr1 << std::endl
           << "  Which is: " << value1 << std::endl
           << "Difference: " << diff.toString() << std::endl
           << " Tolerance: " << tolerance.toString(diff);
}
//! \endcond

/*! \brief
 * Asserts that two single-precision values are within the given tolerance.
 *
 * \hideinitializer
 */
#define EXPECT_FLOAT_EQ_TOL(value1, value2, tolerance) \
    EXPECT_PRED_FORMAT3(::gmx::test::assertEqualWithinTolerance<float>, \
                        value1, value2, tolerance)
/*! \brief
 * Asserts that two double-precision values are within the given tolerance.
 *
 * \hideinitializer
 */
#define EXPECT_DOUBLE_EQ_TOL(value1, value2, tolerance) \
    EXPECT_PRED_FORMAT3(::gmx::test::assertEqualWithinTolerance<double>, \
                        value1, value2, tolerance)
/*! \def EXPECT_REAL_EQ_TOL
 * \brief
 * Asserts that two `real` values are within the given tolerance.
 *
 * \hideinitializer
 */
/*! \brief
 * Asserts that two single-precision values are within the given tolerance.
 *
 * \hideinitializer
 */
#define ASSERT_FLOAT_EQ_TOL(value1, value2, tolerance) \
    ASSERT_PRED_FORMAT3(::gmx::test::assertEqualWithinTolerance<float>, \
                        value1, value2, tolerance)
/*! \brief
 * Asserts that two double-precision values are within the given tolerance.
 *
 * \hideinitializer
 */
#define ASSERT_DOUBLE_EQ_TOL(value1, value2, tolerance) \
    ASSERT_PRED_FORMAT3(::gmx::test::assertEqualWithinTolerance<double>, \
                        value1, value2, tolerance)
/*! \def ASSERT_REAL_EQ_TOL
 * \brief
 * Asserts that two `real` values are within the given tolerance.
 *
 * \hideinitializer
 */

#if GMX_DOUBLE
#define EXPECT_REAL_EQ_TOL(value1, value2, tolerance) \
    EXPECT_DOUBLE_EQ_TOL(value1, value2, tolerance)
#define ASSERT_REAL_EQ_TOL(value1, value2, tolerance) \
    ASSERT_DOUBLE_EQ_TOL(value1, value2, tolerance)
#else
#define EXPECT_REAL_EQ_TOL(value1, value2, tolerance) \
    EXPECT_FLOAT_EQ_TOL(value1, value2, tolerance)
#define ASSERT_REAL_EQ_TOL(value1, value2, tolerance) \
    ASSERT_FLOAT_EQ_TOL(value1, value2, tolerance)
#endif

//! \}

//! \cond internal
/*! \internal \brief
 * Helper method for `(EXPECT|ASSERT)_PLAIN`.
 */
static inline ::testing::AssertionResult
plainAssertHelper(const char * /*expr*/, const ::testing::AssertionResult &expr)
{
    return expr;
}
//! \endcond

/*! \brief
 * Assert for predicates that return AssertionResult and produce a full failure
 * message.
 *
 * `expr` should evaluate to AssertionResult, and on failure the message from
 * the result is used as-is, unlike in EXPECT_TRUE().
 *
 * \hideinitializer
 */
#define EXPECT_PLAIN(expr) EXPECT_PRED_FORMAT1(plainAssertHelper, expr)
/*! \brief
 * Assert for predicates that return AssertionResult and produce a full failure
 * message.
 *
 * `expr` should evaluate to AssertionResult, and on failure the message from
 * the result is used as-is, unlike in ASSERT_TRUE().
 *
 * \hideinitializer
 */
#define ASSERT_PLAIN(expr) ASSERT_PRED_FORMAT1(plainAssertHelper, expr)

//! \}

} // namespace test
} // namespace gmx

#endif