Type Alias: IsolatedImplementation<S>

type IsolatedImplementation<S> = {
  [K in keyof S["methods"]]: (
    args: [...MethodArgs<S["methods"][K]>, ctx?: IsolationCallContext],
  ) => MethodResult<S["methods"][K]> | Promise<MethodResult<S["methods"][K]>>;
} & {
  [K in keyof S["streams"]]: (
    args: [...StreamArgs<S["streams"][K]>, handle: StreamHandle],
  ) =>
    | ReadableStream<StreamDelta<S["streams"][K]>>
    | AsyncIterable<StreamDelta<S["streams"][K]>>;
};

Defined in: src/batteries/isolation/types.ts:284

The guest-side implementation object a caller of serveIsolated must provide — one function per declared method/stream. Method implementations may return their result synchronously or as a Promise. Every method implementation accepts an optional trailing IsolationCallContext uniformly (a deliberate typing simplification — see remarks below); at RUNTIME a context is only ever constructed and passed when the method descriptor declared { signal: true }, so an implementation that ignores the parameter for a non-signal method simply never receives one. Stream implementations may return a ReadableStream<D> or any AsyncIterable<D> (e.g. an async generator), and always receive a trailing StreamHandle. Declared events are NOT part of this object — see serveIsolated's factory emit parameter.

Type Parameters

Type Parameter
S extends IsolatedServiceSpec

Remarks

Conditioning the trailing parameter's presence on S['methods'][K] extends { signal: true } at the type level runs into a genuine TypeScript inference gap: the method<A, R>({ signal: true }) factory can't carry signal's literal-true value through to the mapped type without the descriptor's optional signal?: boolean property widening back to boolean (or true | undefined) well before the conditional type gets to test it, making the extends { signal: true } branch either never trigger or trigger unconditionally. Rather than reach for const-generic phantom-typing surgery to fight that, this mapped type intentionally accepts the simpler, slightly-less-precise contract: the trailing context is always optionally typed, regardless of the descriptor's declared signal option.