@youneed/logger-transport-file

Append log lines to a file — a Node-only transport for @youneed/logger.

import { createLogger, format } from "@youneed/logger";
import { FileTransport } from "@youneed/logger-transport-file";

const log = createLogger({
  format: format.combine(format.timestamp(), format.json()),
  transports: [new FileTransport({ filename: "app.log" })],
});

Modes

• sync (default) — appendFileSync: each record is on disk before log() returns. Simple and crash-safe.
• stream — a buffered append WriteStream; non-blocking and much cheaper under load. Call close() on shutdown to flush.

const t = new FileTransport({ filename: "app.log", stream: true });
// ... on SIGTERM:
await t.close();

Build

pnpm --filter @youneed/logger-transport-file run build