Optional and nullable properties won't be really optional in generated request class

[szhajdu]

openapi: 3.0.1

info:
  title: Test Api
  version: '1'
  description: Test Api

paths:
  '/examples':
    patch:
      requestBody:
        required: true
        content:
          application/json:
            schema:
              type: object
              properties:
                foo:
                  type: integer
                  nullable: true
                bar:
                  type: integer
                  nullable: true
            examples:
              Example 1A:
                value:
                  foo: 1
              Example 1B:
                value:
                  foo: null
              Example 2A:
                value:
                  bar: 2
              Example 2B:
                value:
                  bar: null
              Example 3A:
                value:
                  foo: 1
                  bar: 2
              Example 3B:
                value:
                  foo: null
                  bar: null
      responses:
        204:
          description: Updated successfully

The toArray method in generated request body class will always send each optional properties to the endpoint:

public function toArray(): array
{
    $fields        = [];
    $fields['foo'] = $this->foo;
    $fields['bar'] = $this->bar;

    return $fields;
}

If I remove the nullable: true modifier, it will generate optional properties, but it won't be nullable anymore:

public function toArray(): array
{
    $fields        = [];
    if ($this->foo !== null) {
        $fields['foo'] = $this->foo;
    }
    if ($this->bar !== null) {
        $fields['bar'] = $this->bar;
    }

    return $fields;
}

I think the request object should know if a property has been set or not instead of checking default null values. Maybe maintain flags or use some specific value for it.

[vsouz4]

I understand your point, but:

• the concept here I guess is pretty similar to uninitialized vs null concept; an optional field uninitialized is theoretically different from a nullable field set with null, but there's no clear way to differentiate them in PHP without some ugly/hacky reflection check and only then support that for 7.4+ exclusively. isset would say false for both the property set with null and the uninitialized one.
• I checked this discussion https://github.com/php/php-src/pull/7029 and https://externals.io/message/114607 and I guess relying on uninitialized properties for this won't be a good idea, and any other way would be even uglier (like maintaining flags for each property "set / not set" or some special value meaning "not set")
• I'm thinking also whether the API receiving this request should have different logics linked with absence of parameter or parameter with null value, maybe it's a design issue instead? Do you have a valid example where this would make sense?

[szhajdu]

Most probably this is a design issue, but there are legacy APIs and I can imagine that something is depends on this functionality. The optional nullable properties are part of openapi specification and it should be supported by the generator as well, or at least marked as unsupported feature and generation should fail in these situations, otherwise the generated code won't match with the specification and it could lead to unexpected issues on the user side.

[vsouz4]

it's misleading indeed, added PR with your suggestion, thx