function yourfunction($a,$z){
   if($a<$z){ throw new <YOUR_EXCEPTION>; }
}

下面是测试

class FunctionTest extends \PHPUnit_Framework_TestCase{

   public function testException(){

      $this->setExpectedException(<YOUR_EXCEPTION>::class);
      yourfunction(1,2);//add vars that cause the exception 

   }

}

/**
 * @expectedException Exception
 * @expectedExceptionMessage Amount has to be bigger then 0!
 */
public function testDepositNegative()
{
    $this->account->deposit(-7);
}

注意“/**”，注意两个“*”。只写“**”(星号)将使代码失败。 同时确保你使用的是phpUnit的最新版本。在phpunit的一些早期版本中，不支持@expectedException异常。我有4.0，它不适合我，我必须更新到5.5 https://coderwall.com/p/mklvdw/install-phpunit-with-composer更新与作曲家。

全面的解决方案

PHPUnit当前异常测试的“最佳实践”似乎…低迷(文档)。

由于我想要的不仅仅是当前的expectException实现，所以我在测试用例中使用了一个trait。它只有大约50行代码。

每个测试支持多个异常 支持异常抛出后调用的断言 健壮和清晰的使用示例 标准断言语法 不仅支持消息、代码和类的断言 支持反向断言，assertNotThrows 支持PHP 7可抛出错误

图书馆

我发布了AssertThrows trait到Github和packagist，这样它就可以与composer一起安装了。

简单的例子

只是为了说明语法背后的精神:

<?php

// Using simple callback
$this->assertThrows(MyException::class, [$obj, 'doSomethingBad']);

// Using anonymous function
$this->assertThrows(MyException::class, function() use ($obj) {
    $obj->doSomethingBad();
});

很整洁的?

完整使用示例

请看下面一个更全面的使用示例:

<?php

declare(strict_types=1);

use Jchook\AssertThrows\AssertThrows;
use PHPUnit\Framework\TestCase;

// These are just for illustration
use MyNamespace\MyException;
use MyNamespace\MyObject;

final class MyTest extends TestCase
{
    use AssertThrows; // <--- adds the assertThrows method

    public function testMyObject()
    {
        $obj = new MyObject();

        // Test a basic exception is thrown
        $this->assertThrows(MyException::class, function() use ($obj) {
            $obj->doSomethingBad();
        });

        // Test custom aspects of a custom extension class
        $this->assertThrows(MyException::class, 
            function() use ($obj) {
                $obj->doSomethingBad();
            },
            function($exception) {
                $this->assertEquals('Expected value', $exception->getCustomThing());
                $this->assertEquals(123, $exception->getCode());
            }
        );

        // Test that a specific exception is NOT thrown
        $this->assertNotThrows(MyException::class, function() use ($obj) {
            $obj->doSomethingGood();
        });
    }
}

?>

public function testException() {
    try {
        $this->methodThatThrowsException();
        $this->fail("Expected Exception has not been raised.");
    } catch (Exception $ex) {
        $this->assertEquals("Exception message", $ex->getMessage());
    }
    
}

PHPUnit expectException方法非常不方便，因为它只允许每个测试方法测试一个异常。

我使用这个helper函数来断言某个函数抛出异常:

/**
 * Asserts that the given callback throws the given exception.
 *
 * @param string $expectClass The name of the expected exception class
 * @param callable $callback A callback which should throw the exception
 */
protected function assertException(string $expectClass, callable $callback)
{
    try {
        $callback();
    } catch (\Throwable $exception) {
        $this->assertInstanceOf($expectClass, $exception, 'An invalid exception was thrown');
        return;
    }

    $this->fail('No exception was thrown');
}

将它添加到您的测试类中，并以这样的方式调用:

public function testSomething() {
    $this->assertException(\PDOException::class, function() {
        new \PDO('bad:param');
    });
    $this->assertException(\PDOException::class, function() {
        new \PDO('foo:bar');
    });
}

您可以使用assertException扩展在一次测试执行期间断言多个异常。

插入方法到您的TestCase并使用:

public function testSomething()
{
    $test = function() {
        // some code that has to throw an exception
    };
    $this->assertException( $test, 'InvalidArgumentException', 100, 'expected message' );
}

我还为喜欢漂亮代码的人做了一个trait ..