Error validating query arguments of type array

[mam08ixo]

There are several ways to express arrays in query strings:

The array

"list": [
    "foo",
    "bar"
]

may be serialized into list[]=foo&list[]=bar or list=foo&list=bar.

Depending on the server backend, the latter variant may be required. When using this format though, request validation breaks:

openapi-psr7-validator/src/PSR7/Validators/SerializedParameter.php

Lines 174 to 176 in 5f98f98

	foreach ($value as &$val) {
	$val = $this->castToSchemaType($val, $schema->items->type ?? null);
	}

Invalid argument supplied for foreach()

The issue is caused by the usage of the parse_str function, which can only handle PHP-style query args and turns multiple arguments with the same name into a string with the last value ("bar"):

openapi-psr7-validator/src/PSR7/Validators/QueryArgumentsValidator.php

Line 74 in 5f98f98

parse_str($message->getUri()->getQuery(), $parsedQueryArguments);

This drawback is also mentioned in the user contributed notes of the parse_str documentation.

The objective would be to properly parse all array query string formats that are mentioned in the OpenAPI Guide.

[mam08ixo]

\GuzzleHttp\Psr7\Query::parse handles my use case pretty well, but, as noted there, not the PHP style array.