drwpow/openapi-fetch

index.d.ts broken - "Type 'U' cannot be used to index type 'T'."

shoffmeister opened this issue · 6 comments

shoffmeister commented

Description

The index.d.ts generated for openapi-fetch causes (my) Typescript compiler to complain "Type 'U' cannot be used to index type 'T'."

Reproduction

  • Clean plate
git clone https://github.com/drwpow/openapi-fetch.git
git checkout v0.0.6

cd openapi-fetch
npm install
  • Place attached file repro.ts.txt as repro.ts into the root of the repository
  • npx tsc repro.ts

// exp: no diagnostics
//act:

Type 'U' cannot be used to index type 'T'.
Type 'M' cannot be used to index type 'T[U]'.

Trigger is the following part in index.d.ts:

export default function createClient<T>(defaultOptions?: ClientOptions): {
    /** Call a GET endpoint */
    get<U extends { [Path in keyof T]: T[Path] extends {
        get: unknown;
    } ? Path : never; }[keyof T], M extends keyof T[U]>(url: U, options: (T[U][M] extends infer T ? T extends T[U][M] ? T extends {
        parameters: any;
    } ? {
shoffmeister commented

Perhaps my package-lock.json provides additional clues? See package-lock.json.gz

shoffmeister commented

FWIW, the raw Typescript file - i.e. index.ts as shipped via npm - is doing fine.

Vendoring this file works, but doing that quite obviously is The Wrong Thing to do :)

drwpow commented

What TypeScript version are you using? I recently upgraded to 5.x and noticed some slight differences and wondering if there’s a 4.x <> 5.x error

shoffmeister commented

With the package-lock.json (above) this is 5.0.4; I think I tried 4.9.5, too (with the same result) - and when I noticed that your package.json had ^5.0.3, I simply created this issue here.

I am on Fedora Linux 37, and the only global Javascript / Typescript bits and pieces are "dnf install nodejs" (which is 18.9.5 right now IIRC). The rest all comes via npm into local node_modules.

xobotyi commented

Same issue, TS 5.0.3

upd: downgrade to 4.9.5 didn't help either
upd2: had to set "skipLibCheck": true, to overcome issue

drwpow commented

Ah I’m seeing this as well :/. It only seems to exist in the built types, not the source files. Not sure if it’s a TypeScript bug or what. But this should be fixable.

skipLibCheck: true is recommended as a workaround for now.