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?
• What's the actual output vs expected output?
• [Optional] Sponsorship to speed up the bug fix or feature request (example)

Description

File uploads fail on server-side as the "file" part are missing necessary headers.

openapi-generator version

5.1.0

OpenAPI declaration file content or url

Relevant snippet below:

    "/upload": {
      "post": {
        "tags": [
          "Upload"
        ],
        "summary": "Upload log files",
        "operationId": "post",
        "parameters": [
          {
            "name": "accountId",
            "in": "query",
            "required": true,
            "schema": {
              "type": "string"
            }
          },
          {
            "name": "type",
            "in": "query",
            "required": true,
            "schema": {
              "type": "string"
            }
          }
        ],
        "requestBody": {
          "content": {
            "multipart/form-data": {
              "schema": {
                "type": "object",
                "properties": {
                  "file": {
                    "type": "string",
                    "format": "binary"
                  }
                }
              }
            }
          }
        },
        "responses": {

Generation Details

Language: Kotlin
Library: Multiplatform

Steps to reproduce

1. Run openapi-generator-cli: openapi-generator-cli generate -g kotlin -o logging-api-client -i api-docs.json -c config.yaml --library multiplatform
2. Compile generated code and attempt a file upload

Suggest a fix

I was able to modify the source for the UploadApi class to include the ContentType and ContentDisposition headers and the upload behaved as expected.

ModifiedUploadApi.kt.txt

UploadApi.kt.txt

get input provider snippet.kt.txt