Logging

Observe retry decisions, exhaustion, and cancellation with an optional logger.

runRetryPolicy(...) accepts an optional logger?: Logger option from logger. Pass one to observe retry internals; omit it and nothing is logged — zero overhead.

import { ConsoleLogger } from "@zap-studio/logger";
import { exponentialBackoff, runRetryPolicy } from "@zap-studio/retry";

const logger = new ConsoleLogger({ minLevel: "debug" });
const policy = exponentialBackoff({ maxAttempts: 5, baseDelayMs: 100 });

await runRetryPolicy(policy, execute, { logger });

What Gets Logged

Exhaustion logs at warn rather than debug because it means the caller’s work ultimately failed — worth surfacing by default when a logger is attached, without being so verbose that a passing retry sequence floods debug output on its own.

Bring Your Own Logger

Any object implementing the Logger interface works, so you can forward these events into an existing logging setup instead of ConsoleLogger:

import type { Logger } from "@zap-studio/logger";

const logger: Logger = {
  trace: (message, context) => myBackend.log("trace", message, context),
  debug: (message, context) => myBackend.log("debug", message, context),
  info: (message, context) => myBackend.log("info", message, context),
  warn: (message, context) => myBackend.log("warn", message, context),
  error: (message, context) => myBackend.log("error", message, context),
  fatal: (message, context) => myBackend.log("fatal", message, context),
};

await runRetryPolicy(policy, execute, { logger });

See logger for the full Logger interface and ConsoleLogger options.