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Adding tests for xlnt::detail::float_equals
-- Plenty of comments which should be useful if it becomes useful to tweak the comparison
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Crzyrndm
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a28f3fb7a9
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9565377963
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@ -15,6 +15,7 @@ if(STATIC_CRT)
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endif()
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file(GLOB CELL_TESTS ${CMAKE_CURRENT_SOURCE_DIR}/cell/*.cpp)
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file(GLOB DETAIL_TESTS ${CMAKE_CURRENT_SOURCE_DIR}/detail/*.cpp)
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file(GLOB PACKAGING_TESTS ${CMAKE_CURRENT_SOURCE_DIR}/packaging/*.cpp)
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file(GLOB STYLES_TESTS ${CMAKE_CURRENT_SOURCE_DIR}/styles/*.cpp)
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file(GLOB UTILS_TESTS ${CMAKE_CURRENT_SOURCE_DIR}/utils/*.cpp)
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@ -23,6 +24,7 @@ file(GLOB WORKSHEET_TESTS ${CMAKE_CURRENT_SOURCE_DIR}/worksheet/*.cpp)
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set(TESTS
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${CELL_TESTS}
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${DETAIL_TESTS}
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${PACKAGING_TESTS}
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${STYLES_TESTS}
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${UTILS_TESTS}
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@ -59,6 +61,7 @@ endif()
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source_group(helpers FILES ${HELPERS})
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source_group(runner FILES ${RUNNER})
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source_group(tests\\cell FILES ${CELL_TESTS})
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source_group(tests\\detail FILES ${DETAIL_TESTS})
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source_group(tests\\packaging FILES ${PACKAGING_TESTS})
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source_group(tests\\serialization FILES ${SERIALIZATION_TESTS})
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source_group(tests\\styles FILES ${STYLES_TESTS})
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112
tests/detail/numeric_util_test_suite.cpp
Normal file
112
tests/detail/numeric_util_test_suite.cpp
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@ -0,0 +1,112 @@
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// Copyright (c) 2014-2018 Thomas Fussell
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//
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// Permission is hereby granted, free of charge, to any person obtaining a copy
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// of this software and associated documentation files (the "Software"), to deal
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// in the Software without restriction, including without limitation the rights
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// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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// copies of the Software, and to permit persons to whom the Software is
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// furnished to do so, subject to the following conditions:
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//
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// The above copyright notice and this permission notice shall be included in
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// all copies or substantial portions of the Software.
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//
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// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, WRISING FROM,
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// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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// THE SOFTWARE
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//
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// @license: http://www.opensource.org/licenses/mit-license.php
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// @author: see AUTHORS file
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#include "../../source/detail/numeric_utils.hpp"
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#include <helpers/test_suite.hpp>
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class numeric_test_suite : public test_suite
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{
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public:
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numeric_test_suite()
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{
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register_test(test_float_equals_zero);
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register_test(test_float_equals_large);
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}
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void test_float_equals_zero()
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{
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// comparing relatively small numbers (2.3e-6) with 0 will be true by default
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const float comp_val = 2.3e-6; // about the largest difference allowed by default
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xlnt_assert(0.f != comp_val); // fail because not exactly equal
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xlnt_assert(xlnt::detail::float_equals(0.0, comp_val));
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xlnt_assert(xlnt::detail::float_equals(0.0, -comp_val));
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// fail because diff is out of bounds for fuzzy equality
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xlnt_assert(!xlnt::detail::float_equals(0.0, comp_val + 0.1e-6));
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xlnt_assert(!xlnt::detail::float_equals(0.0, -(comp_val + 0.1e-6)));
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// if the bounds of comparison are too loose, there are two tweakable knobs to tighten the comparison up
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//==========================================================
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// #1: reduce the epsilon_scale (default is 20)
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// This can bring the range down to FLT_EPSILON (scale factor of 1)
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xlnt_assert(!xlnt::detail::float_equals(0.0, comp_val, 10));
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const float closer_comp_val = 1.1e-6;
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xlnt_assert(xlnt::detail::float_equals(0.0, closer_comp_val, 10));
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xlnt_assert(!xlnt::detail::float_equals(0.0, closer_comp_val + 0.1e-6, 10));
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xlnt_assert(xlnt::detail::float_equals(0.0, -closer_comp_val, 10));
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xlnt_assert(!xlnt::detail::float_equals(0.0, -(closer_comp_val + 0.1e-6), 10));
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//==========================================================
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// #2: specify the epsilon source as a higher precision type (e.g. double)
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// This makes the epsilon range quite significantly less
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xlnt_assert(!xlnt::detail::float_equals<double>(0.0, comp_val));
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xlnt_assert(!xlnt::detail::float_equals<double>(0.0, closer_comp_val));
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const float tiny_comp_val = 4.4e-15;
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xlnt_assert(xlnt::detail::float_equals<double>(0.0, tiny_comp_val));
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xlnt_assert(!xlnt::detail::float_equals<double>(0.0, tiny_comp_val + 0.1e-15));
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xlnt_assert(xlnt::detail::float_equals<double>(0.0, -tiny_comp_val));
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xlnt_assert(!xlnt::detail::float_equals<double>(0.0, -(tiny_comp_val + 0.1e-15)));
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//==========================================================
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// #3: combine #1 & #2
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// for the tightest default precision, double with a scale of 1
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xlnt_assert(!xlnt::detail::float_equals<double>(0.0, comp_val, 1));
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xlnt_assert(!xlnt::detail::float_equals<double>(0.0, closer_comp_val, 1));
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xlnt_assert(!xlnt::detail::float_equals<double>(0.0, tiny_comp_val, 1));
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const float really_tiny_comp_val = 2.2e-16; // the limit is +/- std::numeric_limits<double>::epsilon()
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xlnt_assert(xlnt::detail::float_equals<double>(0.0, really_tiny_comp_val, 1));
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xlnt_assert(!xlnt::detail::float_equals<double>(0.0, really_tiny_comp_val + 0.1e-16, 1));
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xlnt_assert(xlnt::detail::float_equals<double>(0.0, -really_tiny_comp_val, 1));
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xlnt_assert(!xlnt::detail::float_equals<double>(0.0, -(really_tiny_comp_val + 0.1e-16), 1));
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//==========================================================
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// in the world of floats, 2.2e-16 is still significantly different to 0.f (smallest representable float is around 1e-38)
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// if comparisons are known to involve extremely small numbers (such that +/- 2.2e-16 is too large a band),
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// a type that specialises std::numeric_limits::epsilon may be passed as the first template parameter
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// the type itself doesn't actually need to have any behaviour as it is only used as the source for epsilon
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// struct super_precise{};
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// namespace std {
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// template<> numeric_limits<super_precise> {
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// double epsilon() {
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// return 1e-30;
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// }
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// }
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// }
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// float_equals<double>(0.0, 2e-30, 1); // returns true
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// float_equals<super_precise>(0.0, 2e-30, 1); // returns false
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}
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void test_float_equals_large()
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{
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const float compare_to = 20e6;
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// fp math with arguments of different magnitudes is wierd
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xlnt_assert(compare_to == compare_to + 1); // x == x + 1 ...
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xlnt_assert(compare_to != compare_to + 10); // x != x + 10
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xlnt_assert(compare_to != compare_to - 10); // x != x - 10
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// if the same epsilon was used for comparison of large values as the values around one
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// we'd have all the issues around zero again
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xlnt_assert(xlnt::detail::float_equals(compare_to, compare_to + 49));
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xlnt_assert(!xlnt::detail::float_equals(compare_to, compare_to + 50));
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xlnt_assert(xlnt::detail::float_equals(compare_to, compare_to - 49));
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xlnt_assert(!xlnt::detail::float_equals(compare_to, compare_to - 50));
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// float_equals also scales epsilon up to match the magnitude of its arguments
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// all the same options are available for increasing/decreasing the precision of the comparison
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// however the the epsilon source should always be of equal or lesser precision than the arguments when away from zero
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}
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};
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static numeric_test_suite x;
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