Missing individual parts content-types in multipart/formdata requests.

[mateusbandeiraa]

Q&A (please complete the following information)

• OS: MacOS
• Environment: Chrome 115.0.5762.4, Node v18.16.0
• Method of installation: npm
• Swagger-Client version: 3.19.7
• Swagger/OpenAPI version: OpenAPI 3.0

Content & configuration

Swagger/OpenAPI definition:

openapi: 3.0.0
info:
  title: 'Test Swagger'
  description: 'Test Swagger'
  contact:
    email: test@swagger.com
  version: '1'
servers:
  - url: https://demo7917836.mockable.io/
paths:
  /api/v1/profile:
    post:
      tags:
        - Profile
      summary: 'profile of the user user'
      requestBody:
        description: 'Profile that needs to be stored'
        content:
          multipart/form-data:
            schema:
              type: object
              properties:
                avatar_image:
                  description: avatar_image
                  type: string
                  format: binary
                profile:
                  $ref: '#/components/schemas/Profile'
            encoding:
              profile:
                contentType: application/json
      responses:
        201:
          description: 'Profile that was registered.'
          content:
            application/json:
              schema:
                type: object
        422:
          description: 'Unprocessable Entity.'
          content:
            application/json:
              schema:
                type: object
components:
  schemas:
    Profile:
      title: Profile
      description: 'profile model'
      required:
        - email
        - telephone
      properties:
        email:
          description: 'Email of the profile'
          type: string
        name:
          description: 'Name of the profile'
          type: string
      type: object
tags:
  -
    name: Profile
    description: 'Operations for the user profile'

Swagger-Client usage:

SwaggerClient({
  // your config options here
})

Describe the bug you're encountering

To reproduce...

Steps to reproduce the behavior:

1. Execute the request POST /api/v1/profile with avatar_image as a png file, and profile as a JSON string

Expected behavior

The generated request body should be:

------WebKitFormBoundaryCqXhiFiwHDcc41AS
Content-Disposition: form-data; name="avatar_image"; filename="Captura de Tela 2023-05-13 às 14.57.47.png"
Content-Type: image/png


------WebKitFormBoundaryCqXhiFiwHDcc41AS
Content-Disposition: form-data; name="profile"
Content-Type: application/json

{
  "email": "string",
  "name": "string"
}
------WebKitFormBoundaryCqXhiFiwHDcc41AS--

(notice Content-Type: application/json in the profile part)

Actual behavior

The actual generated request body is:

------WebKitFormBoundary5Y9MMKP3nHioumLz
Content-Disposition: form-data; name="avatar_image"; filename="Captura de Tela 2023-05-13 às 14.57.47.png"
Content-Type: image/png


------WebKitFormBoundary5Y9MMKP3nHioumLz
Content-Disposition: form-data; name="profile"

{
  "email": "string",
  "name": "string"
}
------WebKitFormBoundary5Y9MMKP3nHioumLz--

(notice the missing Content-Type: application/json in the profile part)

Additional context or thoughts

This issue was initially created as swagger-api/swagger-ui#5356, but the required code change to fix this issue is in this repository.

[mateusbandeiraa]

I created a draft PR addessing this issue. I could use some help, since this would be my first contribution. #2955

[mateusbandeiraa]

@char0n Could you take a look at this, please? I have zero familiarity with the project but I really want to fix this bug. Can you give me some guidance on the draft PR?

[char0n]

Hi @mateusbandeiraa, all right, let me have a look. And thanks for contributing!

[char0n]

@mateusbandeiraa can you also please provide the actual code that reproduces this issue? I need an example which I can run and see the results you're describing.

[mateusbandeiraa]

I was doing my testing using swagger ui, with the yaml provided in the issue description. I was able to see the generated requests with the browser DevTools.

openapi: 3.0.0
info:
  title: 'Test Swagger'
  description: 'Test Swagger'
  contact:
    email: test@swagger.com
  version: '1'
servers:
  - url: https://demo7917836.mockable.io/
paths:
  /api/v1/profile:
    post:
      tags:
        - Profile
      summary: 'profile of the user user'
      requestBody:
        description: 'Profile that needs to be stored'
        content:
          multipart/form-data:
            schema:
              type: object
              properties:
                avatar_image:
                  description: avatar_image
                  type: string
                  format: binary
                profile:
                  $ref: '#/components/schemas/Profile'
            encoding:
              profile:
                contentType: application/json
      responses:
        201:
          description: 'Profile that was registered.'
          content:
            application/json:
              schema:
                type: object
        422:
          description: 'Unprocessable Entity.'
          content:
            application/json:
              schema:
                type: object
components:
  schemas:
    Profile:
      title: Profile
      description: 'profile model'
      required:
        - email
        - telephone
      properties:
        email:
          description: 'Email of the profile'
          type: string
        name:
          description: 'Name of the profile'
          type: string
      type: object
tags:
  -
    name: Profile
    description: 'Operations for the user profile'

(the screenshot is from editor.swagger.io because I don't have my personal computer with me right now, but I was serving my own swagger instance for development.)

[char0n]

Addressed in #3078