Looking to implement strong typing for API endpoints in a front end client. Here is the current code snippet:
type URI<T extends string> = { url: T }
type QUERY<T> = { query: { [K in keyof T]: T[K] | T[K][] } }
type DATA<T> = { data: Required<{ [K in keyof T]: T[K] }> }
type PATCHDATA<T> = { data: { [K in keyof T]: T[K] } }
type RESPONSE<T> = { response: { [K in keyof T]: T[K] } }
type ENDPOINT = URI<any> & Partial<QUERY<any> & DATA<any> & PATCHDATA<any> & RESPONSE<any>;
type GET<T extends ENDPOINT> = T
type POST<T extends ENDPOINT> = T;
type GET_ACCOUNT = GET<DATA<{}> & URI<'account/:id'> & QUERY<{ userId: string }> & RESPONSE<{}>>
type GET_ACCOUNTS = GET<URI<'accounts'> & QUERY<{ firstName: string, lastName: string }> & RESPONSE<{ id: string, firstname: string, lastName: string }>>
type CREATE_ACCOUNT = POST<QUERY<{}> & URI<'accounts'> & DATA<{}> & RESPONSE<{}>>
type GETS = GET_ACCOUNT | GET_ACCOUNTS
type POSTS = CREATE_ACCOUNT
type ACCOUNT_ENDPOINTS = GETS | POSTS
Question: How can I trigger a compiler error when attempting to include DATA in a GET endpoint? In GET_ACCOUNT, where it specifies GET<DATA<{}>>, I want a visual indicator (like a red squiggly line) and an error message stating that 'A GET request cannot contain a data property'. I have tried different versions of OMIT<> and EXCLUDE<>
attempts
type GET<T extends Omit<ENDPOINT, 'data'> = T
type GET<T extends Pick<ENDPOINT, Exclude<keyof ENDPOINT, 'data'>>> = T