[BUG][PHP] DateTime in query param passes DateTime object to Guzzle, causing error

[jaydiablo]

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue?
• Have you validated the input using an OpenAPI validator (example)?
• Have you tested with the latest master to confirm the issue still exists?
• Have you searched for related issues/PRs?

Description

In this pull request (#3984) the way that query params are parsed changed. Specifically this change:

https://github.com/OpenAPITools/openapi-generator/pull/3984/files#diff-f8be3e87599b0a25a849609b1492f754c182111899b3c86f3497504fb9f60b8aL482

By removing ObjectSerializer::toQueryValue DateTime objects are not converted to a string (toQueryValue calls toString on the input). This results in the DateTime object being passed to Guzzle, which results in this warning being issued (from this call https://github.com/guzzle/psr7/blob/1.6.1/src/functions.php#L600):

rawurlencode() expects parameter 1 to be string, object given

And then null is returned:

https://3v4l.org/AOU5T

I've confirmed that master still contains the same template that was introduced in #3984: https://github.com/OpenAPITools/openapi-generator/blob/master/modules/openapi-generator/src/main/resources/php/api.mustache#L474-L501

openapi-generator version

This first shows up in 4.3.0, reverting to 4.2.3 fixes it.

OpenAPI declaration file content or url

A sample param in an OpenAPI 2.0 config like this will trigger this generation:

{
    "name": "date",
    "in": "query",
    "description": "date filter",
    "required": false,
    "type": "string",
    "default": "",
    "format": "date"
}

Generation Details

I don't think this is relevant, but generating with this command:

./node_modules/.bin/openapi-generator-cli generate -i ./schema/openapi.json -g php -o ./ -c openapi-generator-config.json

openapi-generator-config.json resembles something like this:

{
    "variableNamingConvention": "camelCase",
    "srcBasePath": "src",
    "packageName": "package",
    "invokerPackage": "package",
    "apiPackage": "Api",
    "modelPackage": "Model"
}

Steps to reproduce

Generating a PHP client from an OpenAPI file (in our case it's OpenAPI 2.0, but as I understand the templates, it will happen with any version that OpenAPI generator supports) that has a "date" or "date-time" formatted query parameter definition will encounter this issue. The petstore example API has some "date" and "date-time" parameters, but they're form parameters, not query parameters, so this issue doesn't show up in those examples.

Suggest a fix

I think that non-collection query parameters still need to be passed through ObjectSerializer::toQueryValue so that toString is called on DateTime objects. I'm not sure how that impacts what #3984 was trying to fix though.

[pogster]

This currently breaks our api client. The query parameter is defined liked this:

          schema:
            type: string
            format: date-time

We pass DateTime, with guzzlehttp/psr7:2.1.0 this results in

In Query.php line 96:
                                                             
  Object of class DateTime could not be converted to string  

[thomasphansen]

This was fixed in #13583! 😄

[vdlp-mw]

@thomasphansen Since this issue is still open, i'll reply here instead of opening another issue.

We are currently running into the same issue described in the OP. The linked PR (#13583) does add support for date time, but assumes the openApiType is \\DateTime.

Our generated API client for the following spec, passes the openApiType as string which is however marked as date-time format.

properties:
    updated_at_after:
        type: string
        format: date-time

Generated client is structured as follows (minor edits made for brevity)

    /**
     * ...
     *
     * @param  \DateTime $updatedAtAfter updatedAtAfter (optional)
     * @param  \DateTime $updatedAtBefore updatedAtBefore (optional)
     * @param  \DateTime $createdAtAfter createdAtAfter (optional)
     * @param  \DateTime $createdAtBefore createdAtBefore (optional)
     * 
     * ....
     *
     */
    public function apiEntitiesGet($updatedAtAfter = null, $updatedAtBefore = null, $createdAtAfter = null, $createdAtBefore = null, $page = null, string $contentType = self::contentTypes['apiEntitiesGet'][0])
    {
        ....

        $queryParams = array_merge($queryParams, ObjectSerializer::toQueryValue(
            $updatedAtAfter,
            'updated_at_after', // param base name
            'string', // openApiType
            'form', // style
            true, // explode
            false // required
        ) ?? []);

Not sure if we missed anything, but how would we get the openApiType be passed as \\DateTime?
We're using v7.2.0 but downgrading to v6.6.0 yields the same results.