PHP单元测试无法通过所有测试

Question

I am creating a class with some unit tests, but i am not able to pass few tests. Example is shown below.

Unit Test

class OffsetTest extends \PHPUnit\Framework\TestCase
{


   /**
    * @dataProvider getIllegalOffsets
    * @expectedException \InvalidArgumentException
    * @param $offset
    */
   public function testIllegalParameters($offset)
    {
        new \OffsetEncodingAlgorithm($offset);

        $this->fail('Exception should be thrown');
    }
    /**
     * Data provider for {@link OffsetTest::testIllegalParameters()}
     * @return array
     */
    public function getIllegalOffsets()
    {
        return [
            [-1],
        ];
    }
}

My Class

<?php

class Offset
{
    public function __construct(int $offset = 13)
    {
       try {
            if ($offset < 0) {
                throw new Exception('Exception should be thrown');
            }
        } catch (Exception $e) {
            return $e->getMessage();
        }
        $this->offset = $offset;
    }
}

This how the test progress go

I want all to be passed

Answer 1

While testing for the testIllegalParameters() which expects an exception in return, you don't have to use try-catch block. Just throw an exception in an if condition simply.

Secondly throw a correct type of exception that is defined in the test case InvalidArgumentException

class Offset
{
    public function __construct(int $offset = 13)
    {
        if ($offset < 0) {
            throw new InvalidArgumentException('Offset should be greater than equal to zero');
        } else {
            $this->offset = $offset;
        }
    }
}