Use another name instead of `client.d.ts` beacuse it is inteded as autogenerated from client.ts while it is not.

[MohsenNz]

Tools like tsc can't see .d.ts files with the same name as a .ts file. Running tsc --noEmit --listFiles in the directory of typescript library, will not show clinet.d.ts, then type checking would fail with npx tsc --noEmit --strict.

My suggestion is client.types.d.ts.
But the best practice is removing .d.ts extension completely (e.g. client.types.ts) while its main purpose is to declare types for JavaScript file not TypeScript. Then use declare global scope or export all the types.