A. 断言 - assertEquals() - 《PHPUnit v4.8 手册》

assertEquals()

assertEquals(mixed $expected, mixed $actual[, string $message = ''])

当两个变量 $expected 和 $actual 不相等时报告错误，错误讯息由 $message 指定。

assertNotEquals() 是与之相反的断言，接受相同的参数。

assertAttributeEquals() 和 assertAttributeNotEquals() 是便捷包装(convenience wrapper)，以某个类或对象的某个 public、protected 或 private 属性作为实际值来进行比较。

值得注意的是，应用 assertEquals() 和 assertNotEquals() 时，如果其中一个变量是数值零（无论整数还是浮点数），另一个变量是字符串，那么会同时比较变量的类型（换言之，会用 === 比较操作符，而不是普通的 == 比较操作符）。在假定 0 == "" 为 true（根据自动类型转换）的情况下使用 assertEquals() 或 assertNotEquals() 这可能会导致问题，因为事实上其判定结果为 false。

例 A.13: assertEquals() 的用法

<?php
class EqualsTest extends PHPUnit_Framework_TestCase
{
    public function testFailure()
    {
        $this->assertEquals(1, 0);
    }
 
    public function testFailure2()
    {
        $this->assertEquals('bar', 'baz');
    }
 
    public function testFailure3()
    {
        $this->assertEquals("foo\nbar\nbaz\n", "foo\nbah\nbaz\n");
    }
 
    public function testFailure4()
    {
        $this->assertEquals("", 0)
    }
}
?>

phpunit EqualsTest
PHPUnit 4.8.0 by Sebastian Bergmann and contributors.
 
FFF
 
Time: 0 seconds, Memory: 5.25Mb
 
There were 3 failures:
 
1) EqualsTest::testFailure
Failed asserting that 0 matches expected 1.
 
/home/sb/EqualsTest.php:6
 
2) EqualsTest::testFailure2
Failed asserting that two strings are equal.
--- Expected
+++ Actual
@@ @@
-'bar'
+'baz'
 
/home/sb/EqualsTest.php:11
 
3) EqualsTest::testFailure3
Failed asserting that two strings are equal.
--- Expected
+++ Actual
@@ @@
 'foo
-bar
+bah
 baz
 '
 
/home/sb/EqualsTest.php:16
 
4) EqualsTest::testFailure4
Failed asserting that 0 matches expected ''.
 
/home/sb/EqualsTest.php:21
 
FAILURES!
Tests: 4, Assertions: 4, Failures: 4.

如果 $expected 和 $actual 是某些特定的类型，将使用更加专门的比较方式，参阅下文。

assertEquals(float $expected, float $actual[, string $message = '', float $delta = 0])

当两个浮点数 $expected 和 $actual 之间的差值（的绝对值）大于 $delta 时报告错误，错误讯息由 $message 指定。

关于为什么 $delta 参数是必须的，请阅读《关于浮点运算，每一位计算机科学从业人员都应该知道的事实》。

例 A.14: 将assertEquals()用于浮点数时的用法

<?php
class EqualsTest extends PHPUnit_Framework_TestCase
{
    public function testSuccess()
    {
        $this->assertEquals(1.0, 1.1, '', 0.2);
    }
 
    public function testFailure()
    {
        $this->assertEquals(1.0, 1.1);
    }
}
?>

phpunit EqualsTest
PHPUnit 4.8.0 by Sebastian Bergmann and contributors.
 
.F
 
Time: 0 seconds, Memory: 5.75Mb
 
There was 1 failure:
 
1) EqualsTest::testFailure
Failed asserting that 1.1 matches expected 1.0.
 
/home/sb/EqualsTest.php:11
 
FAILURES!
Tests: 2, Assertions: 2, Failures: 1.

assertEquals(DOMDocument $expected, DOMDocument $actual[, string $message = ''])

当 $expected 和 $actual 这两个 DOMDocument 对象所表示的 XML 文档对应的无注释规范形式不相同时报告错误，错误讯息由 $message 指定。

例 A.15: assertEquals()应用于 DOMDocument 对象时的用法

<?php
class EqualsTest extends PHPUnit_Framework_TestCase
{
    public function testFailure()
    {
        $expected = new DOMDocument;
        $expected->loadXML('<foo><bar/></foo>');
 
        $actual = new DOMDocument;
        $actual->loadXML('<bar><foo/></bar>');
 
        $this->assertEquals($expected, $actual);
    }
}
?>

phpunit EqualsTest
PHPUnit 4.8.0 by Sebastian Bergmann and contributors.
 
F
 
Time: 0 seconds, Memory: 5.00Mb
 
There was 1 failure:
 
1) EqualsTest::testFailure
Failed asserting that two DOM documents are equal.
--- Expected
+++ Actual
@@ @@
 <?xml version="1.0"?>
-<foo>
-  <bar/>
-</foo>
+<bar>
+  <foo/>
+</bar>
 
/home/sb/EqualsTest.php:12
 
FAILURES!
Tests: 1, Assertions: 1, Failures: 1.

assertEquals(object $expected, object $actual[, string $message = ''])

当 $expected 和 $actual 这两个对象的属性值不相等时报告错误，错误讯息由 $message 指定。

例 A.16: assertEquals()应用于对象时的用法

<?php
class EqualsTest extends PHPUnit_Framework_TestCase
{
    public function testFailure()
    {
        $expected = new stdClass;
        $expected->foo = 'foo';
        $expected->bar = 'bar';
 
        $actual = new stdClass;
        $actual->foo = 'bar';
        $actual->baz = 'bar';
 
        $this->assertEquals($expected, $actual);
    }
}
?>

phpunit EqualsTest
PHPUnit 4.8.0 by Sebastian Bergmann and contributors.
 
F
 
Time: 0 seconds, Memory: 5.25Mb
 
There was 1 failure:
 
1) EqualsTest::testFailure
Failed asserting that two objects are equal.
--- Expected
+++ Actual
@@ @@
 stdClass Object (
-    'foo' => 'foo'
-    'bar' => 'bar'
+    'foo' => 'bar'
+    'baz' => 'bar'
 )
 
/home/sb/EqualsTest.php:14
 
FAILURES!
Tests: 1, Assertions: 1, Failures: 1.

assertEquals(array $expected, array $actual[, string $message = ''])

当 $expected 和 $actual 这两个数组不相等时报告错误，错误讯息由 $message 指定。

例 A.17: assertEquals() 应用于数组时的用法

<?php
class EqualsTest extends PHPUnit_Framework_TestCase
{
    public function testFailure()
    {
        $this->assertEquals(array('a', 'b', 'c'), array('a', 'c', 'd'));
    }
}
?>

phpunit EqualsTest
PHPUnit 4.8.0 by Sebastian Bergmann and contributors.
 
F
 
Time: 0 seconds, Memory: 5.25Mb
 
There was 1 failure:
 
1) EqualsTest::testFailure
Failed asserting that two arrays are equal.
--- Expected
+++ Actual
@@ @@
 Array (
     0 => 'a'
-    1 => 'b'
-    2 => 'c'
+    1 => 'c'
+    2 => 'd'
 )
 
/home/sb/EqualsTest.php:6
 
FAILURES!
Tests: 1, Assertions: 1, Failures: 1.