错误相关信息的输出

当有测试失败时，PHPUnit 全力提供尽可能多的有助于找出问题所在的上下文信息。

Example 2.17. 数组比较失败时生成的错误相关信息输出

<?php
class ArrayDiffTest extends PHPUnit_Framework_TestCase
{
    public function testEquality() {
        $this->assertEquals(
            array(1,2,3 ,4,5,6),
            array(1,2,33,4,5,6)
        );
    }
}
?>

phpunit ArrayDiffTest

PHPUnit 5.0.0 by Sebastian Bergmann and contributors.

F

Time: 0 seconds, Memory: 5.25Mb

There was 1 failure:

1) ArrayDiffTest::testEquality
Failed asserting that two arrays are equal.
--- Expected
+++ Actual
@@ @@
 Array (
     0 => 1
     1 => 2
-    2 => 3
+    2 => 33
     3 => 4
     4 => 5
     5 => 6
 )

/home/sb/ArrayDiffTest.php:7

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

在这个例子中，数组中只有一个值不同，但其他值也都同时显示出来，以提供关于错误发生的位置的上下文信息。

当生成的输出很长而难以阅读时，PHPUnit 将对其进行分割，并在每个差异附近提供少数几行上下文信息。

Example 2.18. 长数组比较失败时生成的错误相关信息输出

<?php
class LongArrayDiffTest extends PHPUnit_Framework_TestCase
{
    public function testEquality() {
        $this->assertEquals(
            array(0,0,0,0,0,0,0,0,0,0,0,0,1,2,3 ,4,5,6),
            array(0,0,0,0,0,0,0,0,0,0,0,0,1,2,33,4,5,6)
        );
    }
}
?>

phpunit LongArrayDiffTest

PHPUnit 5.0.0 by Sebastian Bergmann and contributors.

F

Time: 0 seconds, Memory: 5.25Mb

There was 1 failure:

1) LongArrayDiffTest::testEquality
Failed asserting that two arrays are equal.
--- Expected
+++ Actual
@@ @@
     13 => 2
-    14 => 3
+    14 => 33
     15 => 4
     16 => 5
     17 => 6
 )

/home/sb/LongArrayDiffTest.php:7

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

边缘情况

当比较失败时，PHPUnit 为输入值建立文本表示，然后以此进行对比。这种实现导致在差异指示中显示出来的问题可能比实际上存在的多。

这种情况只出现在对数组或者对象使用 assertEquals 或其他“弱”比较函数时。

Example 2.19. 当使用弱比较时在生成的差异结果中出现的边缘情况

<?php
class ArrayWeakComparisonTest extends PHPUnit_Framework_TestCase
{
    public function testEquality() {
        $this->assertEquals(
            array(1  ,2,3 ,4,5,6),
            array('1',2,33,4,5,6)
        );
    }
}
?>

phpunit ArrayWeakComparisonTest

PHPUnit 5.0.0 by Sebastian Bergmann and contributors.

F

Time: 0 seconds, Memory: 5.25Mb

There was 1 failure:

1) ArrayWeakComparisonTest::testEquality
Failed asserting that two arrays are equal.
--- Expected
+++ Actual
@@ @@
 Array (
-    0 => 1
+    0 => '1'
     1 => 2
-    2 => 3
+    2 => 33
     3 => 4
     4 => 5
     5 => 6
 )

/home/sb/ArrayWeakComparisonTest.php:7

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

在这个例子中，第一个索引项中的 1 and '1' 在报告中被视为不同，虽然 assertEquals 认为这两个值是匹配的。