Type of $_GET

[vasily-kartashov]

Is there a way to specify the type of $_GET superglobal (or alternatively the result's type of parse_str)?

0=                                                 array<int,string>                                 
&&&&a=example                                      array<string,string>                              
x=&y[]=2&y[xxx]=null&0=false                       array<int|string,array<int|string,string>|string> 
x=&y[]=2&y[xxx]=null&0=false&[1]=23                array<int|string,array<int|string,string>|string> 
x=&y[][]=2&y[][1]=null&y[][][]=0&false=-1          array<string,array<int,array<int,array<int,string>>|array<int,string>>|string>
5=6                                                array<int,string> 

With recursive types it would be something like

@var V=array<int|string,string|V>

[weirdan]

That might be quite tricky since $_GET is not read-only: https://3v4l.org/qLFMP . And it's superglobal nature further complicates things, since it could be assigned anywhere.

[vasily-kartashov]

Sorry, I haven't been very precise here. I wasn't talking about a universal annotation that should apply to $_GET superglobal in every context.

But there are situations where we capture the content of $_GET, or pass similar parameters, or expect the "canonical" form, for example:

$request = Request::fromSuperGlobals();

or

$request->withQueryParams($params);

[TysonAndre]

It's implemented in src/Psalm/Internal/Analyzer/Statements/Expression/Fetch/VariableFetchAnalyzer.php

        if (in_array(
            $stmt->name,
            [
                'GLOBALS',
                '_SERVER',
                '_GET',
                '_POST',
                '_FILES',
                '_COOKIE',
                '_SESSION',
                '_REQUEST',
                '_ENV',
            ],
            true
        )
        ) {
            $stmt->inferredType = Type::getArray();
            $context->vars_in_scope['$' . $stmt->name] = Type::getArray();
            $context->vars_possibly_in_scope['$' . $stmt->name] = true;

            return null;
        }

It's easy to do, the main issue is deciding what you want to do. E.g. 0=something is going to be pretty rare in most web apps. (array<string,array|string> might work)

My thoughts would be to use the following union types, or something similar (will have false positives in the very rare cases when you use integers as keys):

I don't think psalm supports recursive union types, or that there are plans to

[
        '_GET' => 'array<string,string|string[]>',  // or array<string,string|array>, if you want to support arbitrary nesting - same for the others
        '_POST' => 'array<string,string|string[]>',
        '_COOKIE' => 'array<string,string|string[]>',
        '_REQUEST' => 'array<string,string|string[]>',
        '_SERVER' => 'array<string,mixed>',
        '_ENV' => 'array<string,string>',
        '_FILES' => 'array<string,array<string,int|string|array<string,int|string>>>',  // Can have multiple files with the same name.
        '_SESSION' => 'array<string,mixed>',
        'GLOBALS' => 'array<string,mixed>',
]

[muglug]

I don't think psalm supports recursive union types

Does Phan?

[TysonAndre]

No

[muglug]

Fixed by #1430