| // Copyright 2019 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #include "util/integer_division.h" |
| |
| #include <chrono> |
| |
| #include "gtest/gtest.h" |
| |
| namespace openscreen { |
| namespace { |
| |
| constexpr int kDenominators[2] = {3, 4}; |
| |
| // Common test routine that tests one of the integer division functions using a |
| // fixed denominator and stepping, one-by-one, over a range of numerators around |
| // zero. |
| template <typename Input, typename Output> |
| void TestRangeAboutZero(int denom, |
| int range_of_numerators, |
| int first_expected_result, |
| Output (*function_to_test)(Input, Input)) { |
| int expected_result = first_expected_result; |
| int count_until_next_change = denom; |
| for (int num = -range_of_numerators; num <= range_of_numerators; ++num) { |
| EXPECT_EQ(expected_result, function_to_test(Input(num), Input(denom))) |
| << "num=" << num << ", denom=" << denom; |
| EXPECT_EQ(expected_result, function_to_test(Input(-num), Input(-denom))) |
| << "num=" << (-num) << ", denom=" << (-denom); |
| |
| --count_until_next_change; |
| if (count_until_next_change == 0) { // Next result will be one higher. |
| ++expected_result; |
| count_until_next_change = denom; |
| } |
| } |
| } |
| |
| TEST(IntegerDivision, DividesAndRoundsUpInts) { |
| auto* const function_to_test = &DivideRoundingUp<int>; |
| for (int denom : kDenominators) { |
| TestRangeAboutZero(denom, denom == 3 ? 11 : 15, -3, function_to_test); |
| } |
| } |
| |
| TEST(IntegerDivision, DividesAndRoundsUpChronoDurations) { |
| auto* const function_to_test = &DivideRoundingUp<std::chrono::milliseconds>; |
| for (int denom : kDenominators) { |
| TestRangeAboutZero(denom, denom == 3 ? 11 : 15, -3, function_to_test); |
| } |
| } |
| |
| // Assumption: DivideRoundingUp() is working (tested by the above two tests). |
| TEST(IntegerDivision, DividesPositivesAndRoundsUp) { |
| for (int num = 0; num <= 6; ++num) { |
| for (int denom = 1; denom <= 6; ++denom) { |
| EXPECT_EQ(DivideRoundingUp(num, denom), |
| DividePositivesRoundingUp(num, denom)); |
| } |
| } |
| } |
| |
| TEST(IntegerDivision, DividesAndRoundsNearestInts) { |
| auto* const function_to_test = &DivideRoundingNearest<int>; |
| for (int denom : kDenominators) { |
| TestRangeAboutZero(denom, denom == 3 ? 10 : 14, -3, function_to_test); |
| } |
| } |
| |
| TEST(IntegerDivision, DividesAndRoundsNearestChronoDurations) { |
| auto* const function_to_test = |
| &DivideRoundingNearest<std::chrono::milliseconds>; |
| for (int denom : kDenominators) { |
| TestRangeAboutZero(denom, denom == 3 ? 10 : 14, -3, function_to_test); |
| } |
| } |
| |
| // Assumption: DivideRoundingNearest() is working (tested by the above two |
| // tests). |
| TEST(IntegerDivision, DividesPositivesAndRoundsNearest) { |
| for (int num = 0; num <= 6; ++num) { |
| for (int denom = 1; denom <= 6; ++denom) { |
| EXPECT_EQ(DivideRoundingNearest(num, denom), |
| DividePositivesRoundingNearest(num, denom)); |
| } |
| } |
| } |
| |
| } // namespace |
| } // namespace openscreen |