Function dedupe

dedupe<TArgs extends any[], T>(
keyFn: (...args: TArgs) => string,
fn: (...args: TArgs) => Promise<T>,
): (...args: TArgs) => Promise<T>
Wraps an async function so that concurrent calls with the same key share a single in-flight promise instead of starting duplicate operations.

Once the shared promise resolves (or rejects), subsequent calls will start a new operation.
Type Parameters
- TArgs extends any[]
  The argument types of the wrapped function.
- T
  The return type of the wrapped function.
Parameters
- keyFn: (...args: TArgs) => string
  A function that computes a cache key from the arguments. Calls with the same key will be deduplicated.
- fn: (...args: TArgs) => Promise<T>
  The async function to wrap.
Returns (...args: TArgs) => Promise<T>
A deduplicated version of fn.
Example
```
import { dedupe } from '@cleverbrush/async';

const fetchUser = dedupe(
    (id: number) => `user-${id}`,
    (id: number) => fetch(`/api/users/${id}`).then(r => r.json())
);

// These two calls share a single fetch:
const [a, b] = await Promise.all([fetchUser(1), fetchUser(1)]);
```
- Defined in libs/async/src/dedupe.ts:37