withStatus()

Wraps a Store<T> in a producer with status and error companion stores.

Signature

function withStatus<T>(store: Store<T>, opts?: WithStatusOptions): WithStatusStore<T>

Parameters

Parameter	Type	Description
store	Store<T>	The source store to wrap.
opts	WithStatusOptions	Optional configuration.

Returns

WithStatusStore<T> — a new store with status and error companions. Single upstream subscription with proper teardown.

Basic Usage

import { producer, subscribe } from 'callbag-recharge';
import { withStatus } from 'callbag-recharge/utils';

const raw = producer<number>(({ emit }) => {
    setTimeout(() => emit(42), 100);
  });
const tracked = withStatus(raw);
subscribe(tracked.status, s => console.log(s)); // "active" after 100ms
subscribe(tracked, v => console.log(v));         // 42

Options / Behavior Details

• Lifecycle-aware: Subscribes upstream inside a producer(), so teardown cleans up when all downstream sinks disconnect.
• Companions are stores: store.status and store.error are plain Store<T>, subscribable with any sink or framework binding.
• Lifecycle: pending (no data yet) → active (first DATA received) → completed (END) or errored (END with error).
• For async sources: subscribe() does not emit initial values (Rx semantics), so state() stores stay "pending" until .set() is called. Use { initialStatus: "active" } for pre-populated stores.