@serenity-is/domwise / derivedSignal

Function: derivedSignal()

derivedSignal<TDerived, TInput>(input, fn): DerivedSignalLike<TDerived>

Defined in: src/signal-util.ts:226

Creates a derived (computed) signal from a source signal and a transform.

When the source signal changes, the derived value is re-computed via fn. If the source signal's constructor appears to be a computed-capable type, a new instance of that constructor wrapping () => fn(input.value) is attempted; otherwise a lightweight PrimitiveComputed fallback is used. The returned signal exposes a derivedDisposer that unsubscribes from the source.

Type Parameters

TDerived

TDerived

Type of the derived/computed value.

TInput

TInput = any

Type of the source signal's value.

Parameters

input

SignalLike<TInput>

Source signal to derive from. Must be signal-like.

fn

(value) => TDerived

Transform applied to the source value to produce the derived value.

Returns

DerivedSignalLike<TDerived>

A DerivedSignalLike<TDerived> whose value tracks fn(input.value).

Throws

When input is not signal-like.