watch-source

Shared source and callback typing for the watch helpers (watchDebounced, watchThrottled, watchPausable, watchIgnorable, watchOnce, whenever). The helpers accept the same sources as Vue's watch: a ref, a getter, a reactive object, or a tuple of those. This module declares types only and contributes no runtime code.

Usage

import type { WatchSourceInput, WatchSources, WatchSourceValue, WatchValue, WatchOldValue, WatchHelperCallback, WatchCleanupRegistrar } from "@vizejs/composable/watch-source";

Types

WatchSourceInput

A single source accepted by Vue's watch: ref, getter, or reactive object.

type WatchSourceInput = WatchSource<unknown> | object

WatchSources

Every source shape accepted by the watch helpers, including tuples.

type WatchSources = WatchSourceInput | readonly WatchSourceInput[]

WatchSourceValue

Value observed from a single source: the ref/getter value, or the reactive object itself.

type WatchSourceValue<Source> = Source extends WatchSource<infer Value> ? Value : Source extends object ? Source : never

WatchValue

Value delivered to a watch callback for WatchSources: a tuple source maps element-wise, any other source resolves through WatchSourceValue.

type WatchValue<Sources> = Sources extends readonly unknown[] ? { -readonly [Index in keyof Sources]: WatchSourceValue<Sources[Index]> } : WatchSourceValue<Sources>

WatchOldValue

Previous value delivered to a watch callback: undefined is added only when the watcher runs immediately (tuples get it per element, as in Vue).

type WatchOldValue<Sources, Immediate> = Immediate extends true ? Sources extends readonly unknown[] ? { -readonly [Index in keyof Sources]: WatchSourceValue<Sources[Index]> | undefined } : WatchSourceValue<Sources> | undefined : WatchValue<Sources>

WatchHelperCallback

Callback typed from its sources and the immediate flag.

type WatchHelperCallback<Sources, Immediate = false> = WatchCallback< WatchValue<Sources>, WatchOldValue<Sources, Immediate> >

WatchCleanupRegistrar

Cleanup registrar passed as the third argument of a watch callback.

type WatchCleanupRegistrar = Parameters<WatchCallback>[2]