Multipart form properties codegen is not typesafe #756
Description
Motivation
One of the main benefits I get from using swift-openapi-generator is type safety for client code.
However, for multipart form upload requests, it seems like the property codegen is not typesafe, where all properties just get a generic HTTPBody payload.
For example, given this OpenAPI document:
/uploadFile:
post:
operationId: uploadFile
requestBody:
required: true
content:
multipart/form-data:
schema:
type: object
properties:
description:
type: string
description: A text description of the uploaded file
count:
type: integer
description: An integer value associated with the upload
imageFile:
type: string
format: binary
description: The image file to upload
required:
- description
- count
- imageFileThis code is generated for the request body type:
enum Body: Sendable, Hashable {
enum MultipartFormPayload: Sendable, Hashable {
struct DescriptionPayload: Sendable, Hashable {
var body: OpenAPIRuntime.HTTPBody
init(body: OpenAPIRuntime.HTTPBody) {
self.body = body
}
}
case description(OpenAPIRuntime.MultipartPart<Operations.UploadFile.Input.Body.MultipartFormPayload.DescriptionPayload>)
struct CountPayload: Sendable, Hashable {
var body: OpenAPIRuntime.HTTPBody
init(body: OpenAPIRuntime.HTTPBody) {
self.body = body
}
}
case count(OpenAPIRuntime.MultipartPart<Operations.UploadFile.Input.Body.MultipartFormPayload.CountPayload>)
struct ImageFilePayload: Sendable, Hashable {
var body: OpenAPIRuntime.HTTPBody
init(body: OpenAPIRuntime.HTTPBody) {
self.body = body
}
}
case imageFile(OpenAPIRuntime.MultipartPart<Operations.UploadFile.Input.Body.MultipartFormPayload.ImageFilePayload>)
case undocumented(OpenAPIRuntime.MultipartRawPart)
}
case multipartForm(OpenAPIRuntime.MultipartBody<Operations.UploadFile.Input.Body.MultipartFormPayload>)
}So at the call site, you're responsible for producing HTTPBody values that respect the schema, but you get no compile-type safety if you make a mistake:
let multipartBody: MultipartBody<Operations.UploadFile.Input.Body.MultipartFormPayload> = [
.description(.init(payload: .init(body: "This is a test image upload"))),
.count(.init(payload: .init(body: "42"))),
.imageFile(.init(payload: .init(body: .init(fileData)))),
]Ideally, the codegen would produce type safe property payload initializers:
let multipartBody: MultipartBody<Operations.UploadFile.Input.Body.MultipartFormPayload> = [
.description(.init(payload: .init(value: "This is a test image upload"))),
.count(.init(payload: .init(value: 42))),
.imageFile(.init(payload: .init(value: fileData))),
]and you'd get a compiler failure if you passed say a Swift.String as the count value.
Proposed solution
Ideally, the codegen would produce type safe property payload initializers:
let multipartBody: MultipartBody<Operations.UploadFile.Input.Body.MultipartFormPayload> = [
.description(.init(payload: .init(value: "This is a test image upload"))),
.count(.init(payload: .init(value: 42))),
.imageFile(.init(payload: .init(value: fileData))),
]and you'd get a compiler failure if you passed say a Swift.String as the count value.
Alternatives considered
No response
Additional information
No response