import type { Channel } from "node:diagnostics_channel";
import type { Output } from "./output/format.ts";
export declare function colorChannel(output: Output, name: string): string;
/**
 * Render one diagnostics event to the given {@link Output}. The single source for how a diagnostics message looks across `ufp diagnostics` and `ufp watch livestream
 * --diagnostics`: a JSON object per event when `json` is set (so the line is analyzable with `jq`), otherwise a color-coded, timestamped human line.
 *
 * @param output  - The sink to write the rendered line to (the caller chooses stdout or stderr by how it constructed the `Output`).
 * @param name    - The channel name.
 * @param message - The published payload (`undefined` for payload-less channels).
 * @param opts    - `json` selects the machine-readable object form over the human line.
 *
 * @category CLI
 */
export declare function renderDiagnostic(output: Output, name: string, message: unknown, opts?: {
    json?: boolean;
}): void;
/**
 * Subscribe to a set of diagnostics channels, routing each published message to `onMessage(name, message)`. Returns a `Disposable` that detaches every handler, so a
 * caller uses `using feed = subscribeDiagnostics(...)` and the subscriptions tear down at scope exit with no bookkeeping - the same lifetime discipline the rest of the
 * library uses for its event subscriptions.
 *
 * @param selected  - The channels to subscribe to.
 * @param onMessage - Invoked with the channel name and payload on each publication.
 *
 * @returns A `Disposable` that unsubscribes every handler when disposed.
 *
 * @category CLI
 */
export declare function subscribeDiagnostics(selected: readonly Channel[], onMessage: (name: string, message: unknown) => void): Disposable;
//# sourceMappingURL=diagnostics-feed.d.ts.map