PHPUnit9.0 断言-assertEqualsWithDelta()

assertEqualsWithDelta(mixed $expected, mixed $actual, float $delta[, string $message = ''])

PHPUnit9.0 断言集合

当 ​$expected​ 和 ​$actual​ 之间的差的绝对值大于 ​$delta​ 时报告错误，错误讯息由 ​$message​ 指定。
请阅读《What Every Computer Scientist Should Know About Floating-Point Arithmetic》来了解为什么需要有 ​$delta​。
​assertNotEqualsWithDelta()​ 是与之相反的断言，接受相同的参数。
示例 1.20 assertEqualsWithDelta() 的用法

<?php declare(strict_types=1);
use PHPUnit\Framework\TestCase;

final class EqualsWithDeltaTest extends TestCase
{
    public function testFailure()
    {
        $this->assertEqualsWithDelta(1.0, 1.5, 0.1);
    }
}

$ phpunit EqualsWithDeltaTest
PHPUnit latest.0 by Sebastian Bergmann and contributors.

F                                                                   1 / 1 (100%)

Time: 41 ms, Memory: 6.00 MB

There was 1 failure:

1) EqualsWithDeltaTest::testFailure
Failed asserting that 1.5 matches expected 1.0.

/home/sb/EqualsWithDeltaTest.php:8

FAILURES!
Tests: 1, Assertions: 1, Failures: 1.