下面的代码将测试异常消息和异常代码。

重要提示:如果没有抛出预期的异常，它将失败。

try{
    $test->methodWhichWillThrowException();//if this method not throw exception it must be fail too.
    $this->fail("Expected exception 1162011 not thrown");
}catch(MySpecificException $e){ //Not catching a generic Exception or the fail function is also catched
    $this->assertEquals(1162011, $e->getCode());
    $this->assertEquals("Exception Message", $e->getMessage());
}

另一种方法是:

$this->expectException(\InvalidArgumentException::class);
$this->expectExceptionMessage('Expected Exception Message');

请确保您的测试类扩展\PHPUnit_Framework_TestCase。

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');
    });
}

/**
 * @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。

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 

   }

}

对于PHPUnit 5.7.27和PHP 5.6，要在一个测试中测试多个异常，强制进行异常测试是很重要的。如果没有异常发生，则单独使用异常处理来断言exception实例将跳过对情况的测试。

public function testSomeFunction() {

    $e=null;
    $targetClassObj= new TargetClass();
    try {
        $targetClassObj->doSomething();
    } catch ( \Exception $e ) {
    }
    $this->assertInstanceOf(\Exception::class,$e);
    $this->assertEquals('Some message',$e->getMessage());

    $e=null;
    try {
        $targetClassObj->doSomethingElse();
    } catch ( Exception $e ) {
    }
    $this->assertInstanceOf(\Exception::class,$e);
    $this->assertEquals('Another message',$e->getMessage());

}