Helps to understand extract function

[HellPat]

Hey there, I love PHPStan and want to try my first contribution.
I'd love to gather feedback and suggestions for improvement.

The Legacy-Project I'm working on uses extract to pass variables to the View:
This maybe helps with Yii , also see phpstan/phpstan#351

or in older FuelPHP-Projects

I followed your hint at this ticket: phpstan/phpstan#2047

[HellPat]

There are 2 more possible Parameters here. I'd like to Support only the default parameters,
but had problems here.

I get ConstantType as second param, but one could also drop the corresponding int value in.
How do I check for that?

extract(array &$array [,int $flags=EXTR_OVERWRITE [, string $prefix=NULL]] ) : int

[adaamz]

$flags = $scope->getType($expr->args[1]->value);

but you need to check if there is some argument, for example via count($expr->args) >= 2

[HellPat]

should be solved now.

I did a quick research, how often the flags-Attibutes are beeing used.

supported	const	usages	url
[x]	EXTR_OVERWRITE	∞	its the default
[ ]	EXTR_SKIP	675,812	https://github.com/search?l=PHP&q=EXTR_SKIP&type=Code
[ ]	EXTR_PREFIX_ALL	34,886	https://github.com/search?l=PHP&q=EXTR_PREFIX_ALL&type=Code
[ ]	EXTR_PREFIX_INVALID	3,321	https://github.com/search?l=PHP&q=EXTR_PREFIX_INVALID&type=Code
[ ]	EXTR_IF_EXISTS	21,810	https://github.com/search?l=PHP&q=EXTR_IF_EXISTS&type=Code
[ ]	EXTR_PREFIX_IF_EXISTS	mostly tests	...
[ ]	EXTR_REFS	mostly tests	https://github.com/search?l=PHP&q=EXTR_REFS&type=Code

---

Since it's possible to combine the constants, many possible use cases exist.
For my case, only EXP_OVERWRITE ist relevant, so I implemented only this case.

If you want, I could provide support for EXPR_SKIP and EXTR_PREFIX_ALL, too, since they seem to be widely used (but could also go into an other PR).

I just don't want to support combinations like EXTR_OVERWRITE | EXTR_REFS.

WDYT?

[ondrejmirtes]

This needs a bit more work, but we're on a good path :) Thank you.

[ondrejmirtes]

You're accessing args[0] before checking that the argument was passed to the function call.

[ondrejmirtes]

This means that analyzing code with extract() will fail with an internal error. Which shouldn't be the case.

[ondrejmirtes]

I don't really like this usage of array_map (with void) - array map is supposed to transform the array. I'd much rather like a foreach here.

[ondrejmirtes]

You should at least differentiate between: missing second arg (same as OVERWRITE), having OVERWRITE there, having SKIP there.

Currently, you only support OVERWRITE. Supporting SKIP and the PREFIX variants should be there too. If you ask with bitwise mechanics, it's really easy. ($flags->getValue() & EXTR_SKIP === EXTR_SKIP). It's just a question of a few if branches.

I'm pretty sure your current code will crash when the function is called without second argument (extract($vars)) - this combination isn't tested.

[HellPat]

Thanks for your feedback and your patience :-)
I'll need some time to get this right, but I'm on it.

(I don't want to waste your time, and I'll write many more tests to do so.)

[ondrejmirtes]

It might be a better idea to use the actual constant instead of a hardcoded integer. The constant value might change between PHP versions.

[ondrejmirtes]

Hi, thanks for the effort, but I have to close this abandoned PR. Feel free to open a new one if you decide to resume work on this.