Function createFileLogger

scripts/logger.mjs:47–91

* Attempt to construct a winston-backed file logger. Returns `null` if * winston isn't installed (packaged desktop app) or any setup step fails; * `fileLog` then degrades to a no-op. * * @returns {Promise }

()

 * @returns {Promise<import("winston").Logger | null>}
 */
async function createFileLogger() {
  let winston;
  let DailyRotateFileMod;
  try {
    winston = await import("winston");
    DailyRotateFileMod = await import("winston-daily-rotate-file");
  } catch {
    return null;
  }

  try {
    mkdirSync(logDir, { recursive: true });

    const DailyRotateFile =
      DailyRotateFileMod.default ?? DailyRotateFileMod;
    const fileTransport = new DailyRotateFile({
      dirname: logDir,
      filename: "agent-canvas.%DATE%.log",
      datePattern: "YYYY-MM-DD",
      maxFiles: "7d",
      auditFile: join(logDir, ".log-audit.json"),
      createSymlink: false,
    });

    const logger = winston.createLogger({
      level: "debug",
      format: winston.format.combine(
        winston.format.timestamp({ format: "YYYY-MM-DD HH:mm:ss" }),
        winston.format.printf(
          ({ timestamp, level, message }) =>
            `${timestamp} [${level.toUpperCase().padEnd(5)}] ${message}`,
        ),
      ),
      transports: [fileTransport],
    });

    // Swallow any transport-level errors (e.g. disk full) so a logging
    // failure never crashes the dev server.
    logger.on("error", () => {});
    fileTransport.on("error", () => {});
    return logger;
  } catch {
    return null;
  }
}

const fileLogger = await createFileLogger();