[REQ] [typescript-angular] Generate operation-dependent types according to readOnly=true

[pso-aeb]

Is your feature request related to a problem? Please describe.

I'm having problems with the generated types against an API that uses readOnly=true, especially in conjunction with required=true.
The API publishes schemas like:

"MyResource": {
  "required": [ "inputField", "outputField" ],
  "type": "object",
  "properties": {
    "inputField": { "type": "string "},
    "outputField": { "type": "string", "readOnly": true }
...

This schema is used as both RequestBody and RespondeBody in operations.
According to OpenAPI spec (AFAIU) readOnly=true means a client does not have to provide a property in a RequestBody, but it will be present in the ResponseBody.

typescript-angular generator produces a type like:

interface MyResource { 
    inputField: string;
    readonly outputField: string;
}

This type is great when a client handles the response from the server.
But if the client has to produce an instance of this type to create a request he has to fill redundant values:

const requestBody: MyResource = {
  inputField: 'A sensible value that the server will receive',
  outputField: 'A redundant value the server will ignore',
}

Describe the solution you'd like

IMO the generator should produce two types:

interface MyResourceRequest { 
    inputField: string;
}
interface MyResource { 
    inputField: string;
    readonly outputField: string;
}

MyResourceRequest should be used as parameter in the corresponding service implementations instead of MyResource.

...of course this would be a breaking change. So maybe it would need a dedicated flag to activate this.

Describe alternatives you've considered

ATM I am circumventing the typescript compiler with hacky casts to get it done.

[sevenclev]

#4190

[StefanKern]

Hello, is there any timeline / plan to support this?