winstonjs/winston · error · Error

Logger.cli() was removed in winston@3.0.0 Use a custom winst

Error message

Logger.cli() was removed in winston@3.0.0
Use a custom winston.formats.cli() instead.
See: https://github.com/winstonjs/winston/tree/master/UPGRADE-3.0.md

What it means

`Logger.prototype.cli()` was a winston 2.x convenience that switched the logger to CLI-style output formatting. It was removed in the 3.0.0 rewrite, and the method is kept only to throw a migration notice pointing at `winston.formats.cli()` (the format combinator) and the UPGRADE-3.0.md guide.

Source

Thrown at lib/winston/logger.js:638

  /**
   * Backwards compatibility to `exceptions.handle` in winston < 3.0.0.
   * @returns {undefined}
   * @deprecated
   */
  unhandleExceptions(...args) {
    // eslint-disable-next-line no-console
    console.warn(
      'Deprecated: .unhandleExceptions() will be removed in winston@4. Use .exceptions.unhandle()'
    );
    this.exceptions.unhandle(...args);
  }

  /**
   * Throw a more meaningful deprecation notice
   * @throws {Error} - TODO: add throws description.
   */
  cli() {
    throw new Error(
      [
        'Logger.cli() was removed in winston@3.0.0',
        'Use a custom winston.formats.cli() instead.',
        'See: https://github.com/winstonjs/winston/tree/master/UPGRADE-3.0.md'
      ].join('\n')
    );
  }

  /**
   * Bubbles the `event` that occured on the specified `transport` up
   * from this instance.
   * @param {string} event - The event that occured
   * @param {Object} transport - Transport on which the event occured
   * @private
   */
  _onEvent(event, transport) {
    function transportEvent(err) {
      // https://github.com/winstonjs/winston/issues/1364

View on GitHub (pinned to ff0b79de85)

Solutions

Remove the `logger.cli()` call.
Use the CLI format instead: add `winston.format.cli()` to the logger's `format` combine chain.
If CLI coloring/levels behavior is wanted, combine `format.colorize()`, `format.padLevels()`, `format.errors()`, `format.cli()` as needed.
Follow UPGRADE-3.0.md section on CLI output.

Example fix

// before (winston 2.x)
const logger = new winston.Logger();
logger.cli();

// after (winston 3.x)
const logger = winston.createLogger({
  format: winston.format.cli(),
  transports: [new winston.transports.Console()]
});

Defensive patterns

Strategy: validation

Validate before calling

if (typeof logger.cli === 'function') {
  try { logger.cli; } finally { /* cli() always throws on winston 3 — remove the call */ }
}

Type guard

function supportsCli(x) { return typeof x.cli === 'function' && x.constructor && !/removed/.test(x.cli.toString()); }

Try / catch

try {
  logger.cli();
} catch (err) {
  if (err.message.includes('Logger.cli() was removed')) {
    logger.configure({ format: winston.format.cli() });
  } else { throw err; }
}

Prevention

Remove cli() calls when bumping to winston 3 — it always throws
Use `format.cli()` in the format chain instead
Add a startup smoke test that builds the logger with intended format
Scan codebase for `\.cli()` during dependency upgrades

When it happens

Trigger: Calling `logger.cli()` (or `winston.cli()`) on any winston 3 logger instance — always throws, no conditions.

Common situations: Running winston 2.x-era code on winston 3; tutorials showing `winston.cli()`; automated migrations that preserved old method calls.

Related errors

AI-assisted analysis of winstonjs/winston@ff0b79de85 (2026-08-31). Data as JSON: /api/errors/579f28537d88ad32. Report an issue: GitHub.