introducing `OmitReadonly` type to resolve required + readonly/writeonly properties

[tiholic]

closes #432

Pretext:

Say there are 2 properties to a model id and name. Creating a model instance (POST) requires only name to be posted and id would be a readonly property. Generated type would be

type Model {
  readonly id: number;
  name: string;
}

To create an instance of Model for POST, we should be able to pass {name: "john"} Generated services look like: createMode(model: Model) {...}, which do not accept an object with just name property.

Solution:

This PR aims to solve this issue by adding a type modifier, so effectively generated service code looks like: createMode(model: OmitReadOnly<Model>) {...} which strips off any readonly properties and allows passing an object with just the name property.

More about OmitReadonly:

• it omits readonly properties from an object
• it infers the original type in case of passed type is not an object
• it is applied to parameters for "POST", "PUT" or "PATCH" operations and only if it is a "reference" type

Implementation based on https://github.com/ferdikoomen/openapi-typescript-codegen/issues/432#issuecomment-1019519372 by @sweethuman

[aaronschif]

Please change the OmitReadonly imports to type imports. Vite will complain otherwise. Thank you.

https://github.com/ferdikoomen/openapi-typescript-codegen/pull/1145/files#diff-33d2b8dc9fd33ef2b353540e2ff031e54952e1013569382346cab750d11f9da2R33

[jeremyzahner]

We desperately need this. =)

@tiholic Any chance we can get the type import fixed? @ferdikoomen Can we get this merged after?

I'm happy to help. Let me know if I can support in any way.

[tiholic]

@aaronschif @jeremyzahner import converted to a type import

@ferdikoomen I believe this can be prioritised now?

[jeremyzahner]

@tiholic @aaronschif @demo-exe for the time being, you can use https://www.npmjs.com/package/@jshmrtn/openapi-typescript-codegen until @ferdikoomen can have a look.

[giopetris]

Any chance to get this merged?

[dacox]

@tiholic this is interesting. It appears that openapi-typescript-codegen is marking readonly fields as optional, which I think solves the problem you outlined above (not being able to just do createMode({.name }: Model) {...}

We are facing almost the opposite problem - because these readonly fields are optional, we are getting the response model type containing things like optional ids, which we definitely don't want

[cbowal]

Bumping @giopetris's request – would it be possible to get this merged?

[tajnymag]

@mrlubos Maybe this could be merged into your fork?

[mrlubos]

@tajnymag do you mind opening an issue in our repository? I'd like to solve this with write-only too, this pull request seems to work only for read-only