Query array arguments type conversion does not work

[vsapronov]

Expected Behavior

I have the following endpoint in my controller:

@Controller
public class MyController {
    @Get("/dates")
    public MutableHttpResponse<?> echoQueryController(
        @QueryValue(value = "date_array") @Format("yyyy-MM-dd") LocalDate[] dateArray
    ) {
        System.out.println(dateArray.length);
        return HttpResponse.status(HttpStatus.BAD_REQUEST); // this is for testing only!!!
    }
}

When calling this endpoint via HTTP GET to url: /dates?date_array=2022-01-01&date_array=2022-02-02 I would expect dateArray to be an array of two dates correspondingly.

Actual Behaviour

The dateArray is empty array, no warnings or errors provided. The code in controller prints 0.

Steps To Reproduce

1. No special environment is required - just bare minimum micronaut 3.3.3.
2. Run the server with the above controller and try to GET /dates?date_array=2022-01-01&date_array=2022-02-02
3. Check console output

Environment Information

• Mac OS 12.2.1 and also Ubuntu 18.04.6
• JDK 15

Example Application

No response

Version

3.3.3

[vsapronov]

Strangely enough the similar setup works for header arguments:

@Header(value = "Date-Array") @Format("yyyy-MM-dd") LocalDate[] dateArray

This ^ just works and able to parse array of dates from headers.

[vsapronov]

Also everything works for non-array LocalDate argument:

@QueryValue(value = "date") @Format("yyyy-MM-dd") LocalDate date

^ This just works fine, and I see how date formatting code was invoked in micronaut-core.

[vsapronov]

I'm pretty sure the problem is in this line: https://github.com/micronaut-projects/micronaut-core/blob/3.3.x/http/src/main/java/io/micronaut/http/bind/binders/QueryValueArgumentBinder.java#L91

multiValueConversion = conversionService.convert(parameters, context);

It works only for non-array query params. If the argument in context is of array type like in my case it's LocalDate[] then this line make some absurd.

[fwgreen]

This is still an issue and affects @FormParam as well.

[ojebari-ma]

Can you please confirm that this is still an issue in the latest version of Micronaut?