Feature request: assertStrictEquals

[BackEndTea]

The problem

Currently, phpunit has two ways of making sure variables are the same. assertEquals, and assertSame. Doing == and === checks respectively.

The problem comes when we are comparing objects. We can't always use assertSame, as we may not be able to provide the desired object beforehand. So we use assertEquals there. This however leads to problems in code where the properties of a class may not be a single type. Which can be due to union types, or just because of legacy code.

// https://3v4l.org/PpqMI
class Problem
{
    public function __construct(
        private bool|string $issue
    ) {}
}

var_dump(new Problem(true) == new Problem('There is a problem')); // true

The solution

I'd like to propose a new assertion: assertStrictEqals. Which would check every property to be exactly the same. on the two objects. This is already featured in other test frameworks like jest.

Is this something that could be implemented in PHPUnit? If so i'd be happy to provide a PR for it

[sebastianbergmann]

I do not think that a generic comparison of objects based on properties is useful and PHPUnit already has two ways for comparing objects: assertEquals() with custom comparators and assertObjectEquals().

[BackEndTea]

Turns out i've misunderstood how assertEquals operates. And it basically does what i wanted it to do for object all along 😅 .

[webmozart]

@BackEndTea IMO assertEquals() is very helpful for these kinds of comparisons, as its output is much more verbose when comparisons fail compared to assertObjectEquals(). If you want to continue using assertEquals() but with type safety, I recommend using my StrictPHPUnitExtension.