Mark Request parameters with default values as required

[ZachGagnon1]

Describe the bug
Using @RequestParam(required = false) does not work since v2.0.3. It will always show the field as required in the specifications.

To Reproduce
Steps to reproduce the behavior:

• What version of spring-boot you are using?
  3.0.4
• What modules and versions of springdoc-openapi are you using?
  2.0.4
• Provide with a sample code (HelloController) or Test that reproduces the problem
  java

import io.swagger.v3.oas.annotations.tags.Tag;
import lombok.AccessLevel;
import lombok.RequiredArgsConstructor;
import lombok.experimental.FieldDefaults;
import org.springframework.http.MediaType;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

@Tag(name = "Test")
@RestController
@RequestMapping(value = "/api/v2/test", produces = MediaType.APPLICATION_JSON_VALUE)
@RequiredArgsConstructor
@FieldDefaults(level = AccessLevel.PRIVATE, makeFinal = true)
public class TestController {
  @GetMapping
  public ResponseEntity<Void> getTest(
      @RequestParam(defaultValue = "false", required = false) boolean includeClosed) {
    return ResponseEntity.noContent().build();
  }
}

Expected behavior
Expect the swagger docs to say the field is not required.

Screenshots

V2.0.4

V2.0.2

No code has been changed between both pictures. Only the version.

Additional context
Using Java 17

[bnasslahsen]

Not reproducible

If you provide to a GITHUB repo with a Minimal, Reproducible Example - with HelloController that reproduces the problem, then this ticket can be reopened.

[ZachGagnon1]

Not reproducible

If you provide to a GITHUB repo with a Minimal, Reproducible Example - with HelloController that reproduces the problem, then this ticket can be reopened.

Done I updated and posted a controller where the issue is still there. The code ran was the same as the one above. Only change is still the version of the openapi dependancy

[JoeHegarty]

We're also seeing this, setting a param to required=false does not take effect (it's true anyway) in 2.0.3 and later, but works fine in 2.0.2.

The fix for #2021 seems like the most likely cause at a quick glance. We have a mixed Kotlin/Java project, so I am suspecting that may be a prerequisite to repro it if 2021 is the cause. I will try and find some time to come up with a definitive case.

[bnasslahsen]

@ZachGagnon1,

Again not reproducible:

Try providing a GITHUB repo with a Minimal, Reproducible Example - with HelloController that reproduces the problem, then this ticket can be reopened.

@JoeHegarty,

You are describing a kotlin issue

For this one, there is an enhancement for Kotlin projects you read the changelog.
You should try to get the previous behavior:

springdoc.nullable-request-parameter-enabled=false

[tobiberger]

Hi @bnasslahsen, I just stumbled upon the same issue and also created a repository to reproduce it:
https://github.com/tobiberger/demo-default-value-required
I'd say, the issue here is not really the required parameter of @RequestParameter, but it's about the defaultValue. If there is a default value defined, the parameter shouldn't be marked as required, no matter what the Kotlin nullability says.
As you suggested, disabling the new feature you built fixes the breaking change, but I'd still argue that this should still work as before in that case.
Looking at your code, I'd suggest checking for the existence of a default value in the @RequestParam annotation after checking the @Parameter annotation and before checking the Kotlin nullability.

[bnasslahsen]

@tobiberger,

This could be an enhancement. Are you willing to propose a PR for it ?

[tobiberger]

Sure, why not. This should do the trick.