[BUG][PHP] settype(): Argument #2 ($type) must be a valid type

Created by: NickUfer

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Description

The PHP generator sets a field type as mixed when the field can be one of at least 2 types. As seen in the following with value.

https://github.com/ory/kratos-client-php/blob/e072b3b5bd5abdde83b4197aae0ba87a79e44cb1/lib/Model/UiNodeAttributes.php#L62-L74

protected static $openAPITypes = [
    'disabled' => 'bool',
    'label' => '\Ory\Kratos\Client\Model\UiText',
    'name' => 'string',
    'pattern' => 'string',
    'required' => 'bool',
    'type' => 'string',
    'value' => 'mixed', <----- ## HERE ##
    'text' => '\Ory\Kratos\Client\Model\UiText',
    'src' => 'string',
    'href' => 'string',
    'title' => '\Ory\Kratos\Client\Model\UiText'
];

Here value can be one of these values.. string, number or boolean -> the generator makes it a mixed:

https://github.com/ory/kratos/blob/e3cf3da357dfbaa64181d7bfbfe42d1f00b6ef7b/.schema/openapi.json#L1080-L1096 https://github.com/ory/kratos/blob/e3cf3da357dfbaa64181d7bfbfe42d1f00b6ef7b/.schema/openapi.json#L1141-L1155

[...]
"value": {
  "description": "The input's value.",
  "nullable": true,
  "oneOf": [
    {
      "type": "string"
    },
    {
      "type": "number"
    },
    {
      "type": "boolean"
    }
  ]
}
[...]

Later in the generated ObjectSerializer it tries to use settype() for the current data with type mixed, but mixed is not valid for settype() and it never was valid for it either. I don't know how that code came in here. https://www.php.net/manual/en/function.settype.php#refsect1-function.settype-parameters

Line: https://github.com/OpenAPITools/openapi-generator/blob/1d648223e6fdc1adad8967db05d86db9fc49a581/modules/openapi-generator/src/main/resources/php/ObjectSerializer.mustache#L323-L327

Generated Line: https://github.com/OpenAPITools/openapi-generator/blob/1d648223e6fdc1adad8967db05d86db9fc49a581/samples/client/petstore/php/OpenAPIClient-php/lib/ObjectSerializer.php#L332-L336

When he tries to use settype(<value of field 'value'>, 'mixed') it fails with:

settype(): Argument #2 ($type) must be a valid type

Because mixed is not a valid type: https://www.php.net/manual/en/function.settype.php#refsect1-function.settype-parameters

[BUG][PHP] settype(): Argument #2 ($type) must be a valid type

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