Add PHP 8.0 named parameters support

[BrianHenryIE]

Summary

Add support for using PHP 8.0 named parameters.

Closes:

No issue opened.

Details

Trying to call a mocked function like:

$value = get_transient(
    transient: 'my-transient-name'
);

results in:

Error : Unknown named parameter $transient

This now works:

WP_Mock::userFunction('get_transient', [
    'times'  => 1,
    'args'   => [
        'transient' => 'my-transient-name',
    ],
    'return' => 'the-mocked-transient-value',
]);

The changes use the args array's keys as the parameter names in the mocked function.

NB: this does not work:

WP_Mock::userFunction('get_transient')->once()->with(['transient' => 'my-transient-name'])->andReturn('the-mocked-transient-value');

The Functions::createFunction() has already been called and the function skeleton built and eval()'d, which is where the parameter names must be added.

Contributor checklist

• I agree to follow this project's Code of Conduct.
• I have updated the documentation accordingly
• I have added tests to cover changes introduced by this pull request
• All new and existing tests pass

Testing

One test added which skips if the PHP version is too low.

Reviewer checklist

• Code changes review
• Documentation changes review
• Unit tests pass
• Static analysis passes

[coveralls]

coverage: 66.234% (+0.09%) from 66.142% — BrianHenryIE:named-parameters into 10up:trunk

[AndrewJDawes]

Hey, @BrianHenryIE !

It looks like we are anticipating the possibility of mixed array keys - some integers, some not.

And in response, we are taking an all-or-nothing approach where if any array key is an integer, we bail and do not define the function with any named params

What if we instead dynamically filtered the final $functionNamedParameters to only include array keys which are not integers?

Otherwise, looks good to me. I would be interested in seeing this merged!

[BrianHenryIE]

@AndrewJDawes Excellent point, in fact a mix of unnamed and named is valid once the positional parameters come before the named parameters. I added two tests – the case of mixed positional and named, and out-of-order named – and merged your suggestion. I made an extra change to include positional args as $__positional_0 ($0 would be invalid) which TBH I'm not sure was necessary, I may have been on the wrong path before adding @runInSeparateProcess to the tests. All working now anwyay.