如何使用 PHPUnit 测试确切的异常消息，而不是子字符串?

According to the PHPUnit Documentation on @expectedExceptionMessage, the string must only be a substring of the actual Exception thrown.

In one of my validation methods, an array item is pushed for each error that occurs, and the final Exception message is displayed by imploding the array of errors.

class MyClass
{
    public function validate($a, $b, $c, $d)
    {
        if($a < $b) $errors[] = "a < b.";
        if($b < $c) $errors[] = "b < c.";
        if($c < $d) $errors[] = "c < d.";

        if(count($errors) > 0) throw new Exception(trim(implode(" ", $errors)));
    }
}

The problem I have here is that in the PHPUnit test method I check for different combinations. This causes tests to pass that I intend to fail.

/**
 * @expectedException Exception
 * @expectedExceptionMessage a < b.
 */
public function testValues_ALessBOnly()
{
    $myClass = new MyClass()
    $myClass->validate(1, 2, 4, 3);
}

The string of the Exception message is actually "a < b. b < c." but this test still passes. I intend for this test to fail because the message is not exactly what I expect.

Is there a way with PHPUnit to expect an exact string, rather than a substring? I hope to avoid the following:

public function testValues_ALessBOnly()
{
    $myClass = new MyClass()
    $fail = FALSE;

    try
    {
        $myClass->validate(1, 2, 4, 3);
    }
    catch(Exception $e)
    {
        $fail = TRUE;
        $this->assertEquals($e->getMessage(), "a < b.";
    }

    if(!$fail) $this->fail("No Exceptions were thrown.");
}

解决方案

When this question was posted, PHPUnit v3.7 didn't have a solution to this problem. Newer versions have a new @expectedExceptionMessageRegExp option that you can use to add a regular expression to match the exception message against.

Your case, using ^ and $ to force the string to be exactly what is expected, could look like this:

/**
 * @expectedException Exception
 * @expectedExceptionMessageRegExp /^a < b.$/
 */
public function testValues_ALessBOnly()
{
    $myClass = new MyClass()
    $myClass->validate(1, 2, 4, 3);
}