Laravel 7 empty array validation

Question

I'm trying to validate a required (possibly) empty array in my FormRequest.

I'm usign the present and array validation rules, since i want the value to be passed, but it coul be an empty array.

The problem is that my test fail on an empty string (i.e.: ''), telling me that my request doesn't throw an expected ValidationException with that value.

My test cover the following values for the given field:

input value	expected result	test outcome
null	error present	passed
'a string'	error present	passed
''	error present	failed
123	error present	passed
123.456	error present	passed
true	error present	passed
[]	error not present	passed
['a', 'b']	error not present	passed

How can i test that expected request parameter is present, is an array and is possibly an empty array?

Update #1: My Code

The request

class TestRequest extends FormRequest
{
    public function rules()
    {
        return [
            'array_field' => ['present', 'array'],
        ];
    }
}

The test

    public function testTest()
    {
        $tests = [
            [
                'value'     => null,
                'outcome'  => 'failure',
                'message'   => 'Failed asserting that request returned error for when null is passed.',
            ],
            [
                'value'     => 'string',
                'outcome'  => 'failure',
                'message'   => 'Failed asserting that request returned error when non empty string is passed.',
            ],
            [
                'value'     => '',
                'outcome'  => 'failure',
                'message'   => 'Failed asserting that request returned error when empty string is passed.',
            ],
            [
                'value'     => 123,
                'outcome'  => 'failure',
                'message'   => 'Failed asserting that request returned error when integer is passed.',
            ],
            [
                'value'     => 123.456,
                'outcome'  => 'failure',
                'message'   => 'Failed asserting that request returned error when float is passed.',
            ],
            [
                'value'     => true,
                'outcome'  => 'failure',
                'message'   => 'Failed asserting that request returned error when boolean is passed.',
            ],
            [
                'value'     => [],
                'outcome'  => 'success',
                'message'   => 'Failed asserting that request returned no error when empty array is passed.',
            ],
            [
                'value'     => ['a', 'b'],
                'outcome'  => 'success',
                'message'   => 'Failed asserting that request returned no error when filled array is passed.',
            ],
        ];

        foreach ($tests as $test) {
            try {
                $request = new TestRequest([
                    'array_field' => $test['value']
                ]);

                $request
                    ->setContainer(app())
                    ->setRedirector(app(Redirector::class))
                    ->validateResolved();
            } catch (ValidationException $e) {
            }

            if ('failure' == $test['outcome']) {
                $this->assertTrue(
                    isset($e),
                    'Failed asserting that request throw an exception for invalid ' . json_encode($test['value']) . ' value.'
                );

                $this->assertArrayHasKey(
                    'array_field',
                    $e->errors(),
                    $test['message']
                );

                unset($e);
            } else {
                $this->assertFalse(
                    isset($e),
                    $test['message']
                );
            }
        }
    }

PhpUnit output

Update #2: the combinations of rules used

I've tested with

• present + array
• array
• required + array

but none of those make the validation pass.

Update #3: the end

Found this old question that depict my same situation: it seems impossible to achive my goal with available validation rules; this comment states that the closer solution is to use ConvertEmptyStringsToNull to convert empty strings to nulls and test validation just against the null value.

Answer 1

Okay, a lot of things to change. (Do not take this as an attack, just a constructive reply)

First of all, you are not testing correctly. Remember that a test must only test one thing, here you are testing more than one (no problem with a lot of different values) but you are asserting if it passes and if it fails, that is the problem.

You have to use @dataProvider or @testWith to do multiple tests with different values.

So your test would look like this:

/**
 * @dataProvider inputValues
 */
public function testTest($value)
{
    $response = $this->post('/exampleUrl', ['array_field' => $value]);

    $response->assertSessionHasErrors('array_field');
}

public function inputValues()
{
    return [
        'null is passed' => [null],
        'string is passed' => ['string'],
        'empty string is passed' => [''],
        'integer is passed' => [123],
        'float is passed' => [123.456],
        'boolean is passed' => [true]
    ];
}

This way you will get an error like:

phpunit DataTest
PHPUnit 5.7.0 by Sebastian Bergmann and contributors.

...F

Time: 0 seconds, Memory: 5.75Mb

There was 1 failure:

1) DataTest::testTest with data set "empty string is passed" ('')
Session missing error: array_field.

/home/sb/DataTest.php:9

FAILURES!
Tests: 4, Assertions: 4, Failures: 1.

As you can see, I am not testing "successful" things, as those are separate tests. On the tests you assert if it is working, you are already passing a value that is accepted, so you don't have to test if it has no error with an empty array or an array with data, it is explicit on that test.

Please, add more info about what you are testing, as your TestRequest is super weird, you would not require that and all the further setup you have on it to test it.

---

So, to solve your issue, your rules are not correct. As the documentation says: "The field under validation must be present in the input data but can be empty.". If you see the source code you will see that it can have an empty value like null or ''. So you want to use the rule array and that's it. It must be present but it has to be an array, it doesn't matter if it is empty or not. You want that !