[BUG][Go] Latest Go client generator incorrectly handles explode keyword for query parameters

Created by: phynes-sensiblecode

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?
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Description

In v6.2.1 exploded and unexploded query parameter lists are handled correctly by the Go client generator. This is an example of a URL that has been created by an example client. explode is a query parameter with explode=true. noexplode is a query parameter with explode=false:

/v1/dummy?explode=e1&explode=e2&noexplode=n1%2Cn2

The same code generates this URL with the latest Docker image. The unexploded parameter list is exploded, whilst the exploded parameter list has reflect.Value value for each supplied value:

/v1/dummy?explode=reflect.Value+value&explode=reflect.Value+value&noexplode=n1&noexplode=n2

openapi-generator version

Works as expected in v6.2.1. Bug observed with latest Docker image (uploaded to DockerHub on Nov 20, 2022 at 9:15 am).

OpenAPI declaration file content or url

openapi: 3.0.0
info:
  title: Explode demo
  version: 1.0.0
servers:
  - url: http://api.example.com/v1
paths:
  /dummy:
    get:
      summary: Dummy endpoint.
      description: Dummy endpoint to highlight explode.
      parameters:
        - name: explode
          in: query
          description: Parameters that should be exploded.
          explode: true
          schema:
            type: array
            items:
              type: string
        - name: noexplode
          in: query
          description: Parameters that should not be exploded
          explode: false
          schema:
            type: array
            items:
              type: string
      responses:
        '200':    # status code
          description: Dummy response

Generation Details

Generated client using Docker image:

docker run --rm -v "${PWD}:/local" openapitools/openapi-generator-cli:latest generate -i /local/explode.yaml -g go -o /local/out/go

Steps to reproduce

I used a main.go based on an auto-generated example in out/go/docs/DefaultApi.md. configuration.Debug is set to true to enable printing of URLs:

package main

import (
	"context"
	"fmt"
	"os"

	openapiclient "example.com/autogen/openapi"
)

func main() {
	explode := []string{"e1", "e2"}   // []string | Parameters that should be exploded. (optional)
	noexplode := []string{"n1", "n2"} // []string | Parameters that should not be exploded (optional)

	configuration := openapiclient.NewConfiguration()
	configuration.Debug = true

	apiClient := openapiclient.NewAPIClient(configuration)
	r, err := apiClient.DefaultApi.DummyGet(context.Background()).Explode(explode).Noexplode(noexplode).Execute()
	if err != nil {
		fmt.Fprintf(os.Stderr, "Error when calling `DefaultApi.DummyGet``: %v\n", err)
		fmt.Fprintf(os.Stderr, "Full HTTP response: %v\n", r)
	}
}

I used the replace keyword in the go.mod file to point to the autogenerated client library:

replace example.com/autogen/openapi => ./out/go

Building and running main.go shows the malformed URL. The actual query fails due to using a dummy host.

$ go run main.go 
2022/11/22 11:33:27 
GET /v1/dummy?explode=reflect.Value+value&explode=reflect.Value+value&noexplode=n1&noexplode=n2 HTTP/1.1
...

Rebuilding the client with latest-release version of Docker image results in correct URL:

$ go run main.go 
2022/11/22 11:29:33 
GET /v1/dummy?explode=e1&explode=e2&noexplode=n1%2Cn2 HTTP/1.1
...

Related issues/PRs

Can't find any.