Addition of two new assert functions for better validation of different integer types

[Dropelikeit]

To complete the integer checks, nonNegativeInteger and negativeInteger checks have been added.

This PR belongs to the ticket https://github.com/webmozarts/assert/issues/296

[loevgaard]

I guess you are missing a positiveInteger check?

[herndlm]

@loevgaard that one exists already

[Dropelikeit]

@loevgaard sorry, I think the naming is poorly chosen. Maybe it is wise to rename the nonNegativeInteger to unsignedInteger, because it should only be checked if the value is 0 or higher. What do you think?

[loevgaard]

@loevgaard that one exists already

Didn't know that :)

@loevgaard sorry, I think the naming is poorly chosen. Maybe it is wise to rename the nonNegativeInteger to unsignedInteger, because it should only be checked if the value is 0 or higher. What do you think?

I think nonNegativeInteger is the way to go because that's what's used in other places, .e.g https://psalm.dev/docs/annotating_code/type_syntax/scalar_types/

[Dropelikeit]

@loevgaard The psalm was the motivation to write this pull request. I think it would be great if this missing implementation could be added to make such checks so that Psalm understands the variables correctly:

class MyObject {
/**
* @psalm-param non-negative-int $age
*/
public function __construct(private readonly $age)
{
}

public static function create(int $age): self
{
      Assert::nonNegativeInteger($age);

      return new self($age);
}

/**
* @psalm-return non-negative-int
*/
public function getAge(): int
{
      return $this->age;
}

}

[loevgaard]

Yeah, exactly. Makes a lot of sense :)