I want to test a method that can take, as a parameter, either an instance of class Foo or a string. If anything else is passed it throws an Exception.
How do I test that if I don't pass one of the valid types the exception is thrown? How can I make sure that anything other than one of those types will yield an exception?
To elaborate on my comment on the OP - you can use expectException() to tell PHPUnit that you want to assert that an exception is thrown in the following test. See https://phpunit.readthedocs.io/en/8.0/writing-tests-for-phpunit.html#testing-exceptions
Example:
public function testExceptionIsThrown()
{
$this->expectException(WhateverTheException::class);
$class = new ClassToTest;
$class->methodToTest(1); // an integer is not a string or an instance of Foo and should throw an exception
}
if (!($value instanceof Foo || is_string($value))) { throw new \Exception('nope'); } If so, you wouldn't really need to test much more. Just a couple of fails and a pass.
$this->expectException(WhateverTheException::class)and call your method with the wrong parameter type. Check out phpunit.readthedocs.io/en/8.0/…