Incomplete and Skipped Tests

不完整的测试

当您正在处理新的测试用例类时，您可能需要先编写空的测试方法，例如：

public function testSomething()
{
}

跟踪您必须编写的测试。空测试方法的问题在于它们被 PHPUnit 框架解释为成功。这种误解会导致测试报告无用 - 您无法看到测试是否成功或尚未实施。调用$this->fail()未实现的测试方法也无济于事，因为此后测试将被解释为失败。这与将未执行的测试解释为成功一样是错误的。

If we think of a successful test as a green light and a test failure as a red light, we need an additional yellow light to mark a test as being incomplete or not yet implemented. `PHPUnit_Framework_IncompleteTest` is a marker interface for marking an exception that is raised by a test method as the result of the test being incomplete or currently not implemented. `PHPUnit_Framework_IncompleteTestError` is the standard implementation of this interface.

例7.1显示了一个测试用例类SampleTest，它包含一个测试方法，testSomething()。通过在测试方法中调用便利方法markTestIncomplete()（会自动引发PHPUnit_Framework_IncompleteTestError异常），我们将测试标记为不完整。

例7.1：将测试标记为不完整

<?php
use PHPUnit\Framework\TestCase;

class SampleTest extends TestCase
{
    public function testSomething()
    {
        // Optional: Test anything here, if you want.
        $this->assertTrue(true, 'This should already work.'

        // Stop here and mark this test as incomplete.
        $this->markTestIncomplete(
          'This test has not been implemented yet.'
        
    }
}
?>

一个不完整的测试用I PHPUnit 命令行测试运行器的输出中的一个表示，如以下示例所示：

phpunit --verbose SampleTest
PHPUnit 6.4.0 by Sebastian Bergmann and contributors.

I

Time: 0 seconds, Memory: 3.95Mb

There was 1 incomplete test:

1) SampleTest::testSomething
This test has not been implemented yet.

/home/sb/SampleTest.php:12
OK, but incomplete or skipped tests!
Tests: 1, Assertions: 1, Incomplete: 1.

表7.1显示了将测试标记为不完整的 API 。

表7.1.不完整测试的 API

Method	Meaning
void markTestIncomplete()	Marks the current test as incomplete.
void markTestIncomplete(string $message)	Marks the current test as incomplete using $message as an explanatory message.

跳过测试

并非所有测试都可以在每个环境中运行。举个例子，考虑一个数据库抽象层，它为它所支持的不同数据库系统提供了多个驱动程序。MySQL 驱动程序的测试当然只能在 MySQL 服务器可用的情况下运行。

例7.2显示了一个测试用例类DatabaseTest，它包含一个测试方法，testConnection()。在测试用例类的setUp()模板方法中，我们检查 MySQLi 扩展是否可用，markTestSkipped()如果不是，则使用该方法跳过测试。

例7.2：跳过一个测试

<?php
use PHPUnit\Framework\TestCase;

class DatabaseTest extends TestCase
{
    protected function setUp()
    {
        if (!extension_loaded('mysqli')) {
            $this->markTestSkipped(
              'The MySQLi extension is not available.'
            
        }
    }

    public function testConnection()
    {
        // ...
    }
}
?>

S在 PHPUnit 命令行测试运行器的输出中用一个已跳过的测试表示，如以下示例所示：

phpunit --verbose DatabaseTest
PHPUnit 6.4.0 by Sebastian Bergmann and contributors.

S

Time: 0 seconds, Memory: 3.95Mb

There was 1 skipped test:

1) DatabaseTest::testConnection
The MySQLi extension is not available.

/home/sb/DatabaseTest.php:9
OK, but incomplete or skipped tests!
Tests: 1, Assertions: 0, Skipped: 1.

表7.2显示了用于跳过测试的 API 。

表7.2.用于跳过测试的 API

Method	Meaning
void markTestSkipped()	Marks the current test as skipped.
void markTestSkipped(string $message)	Marks the current test as skipped using $message as an explanatory message.

使用 @requires 跳过测试

除了上述方法之外，还可以使用@requires注释来表示测试用例的常见先决条件。

表7.3.可能 @requires 用法

Type	Possible Values	Examples	Another example
PHP	Any PHP version identifier	@requires PHP 5.3.3	@requires PHP 7.1-dev
PHPUnit	Any PHPUnit version identifier	@requires PHPUnit 3.6.3	@requires PHPUnit 4.6
OS	A regexp matching PHP_OS	@requires OS Linux	@requires OS WIN32\|WINNT
function	Any valid parameter to function_exists	@requires function imap_open	@requires function ReflectionMethod::setAccessible
extension	Any extension name along with an optional version identifier	@requires extension mysqli	@requires extension redis 2.2.0

例7.3：使用 @requires 跳过测试用例

<?php
use PHPUnit\Framework\TestCase;

/**
 * @requires extension mysqli
 */
class DatabaseTest extends TestCase
{
    /**
     * @requires PHP 5.3
     */
    public function testConnection()
    {
        // Test requires the mysqli extension and PHP >= 5.3
    }

    // ... All other tests require the mysqli extension
}
?>

如果您使用的语法不是使用特定的 PHP 版本进行编译，请查看名为“测试套件”的部分，查看版本相关的 xml 配置，