Introducing Optic, Deno's most feature-rich, modular and easy to use logger.

[cknight]

Introducing Optic v1.0, Deno's most feature-rich, modular and easy to use logger.

• Log anything
• Custom formatters included, including a date formatter
• Filters to remove unwanted logs
• Transformers to modify your log messages (e.g. hide sensitive data, strip new lines, etc.)
• Monitors to spy on log records that flow through your logger (e.g. collect stats, send alerts, etc)
• Deferred log resolution: logger.info(() => { return calculateExpensiveMsgOnlyIfInfoEnabled(); });
• Inline logging: const user: User = logger.info(getUser());
• Conditional logging: logger.if(attempts > 3).warn("Excessive attempts by user");
• Use env variables or command line args to control the min log level or disable the logger all-together
• FileStream with file size and date/time based log rotation, including log retention policy
• All with an easy to use fluid interface

const logger = new Logger().addStream(
  new FileStream("./logFile.txt")
  .withMinLogLevel(Level.Warn)
  .withFormat(new JsonFormatter().withDateTimeFormat("YYYY-MM-DD hh:mm:ss"))
  .withBufferSize(30000)
  .withLogFileInitMode("append")
  .withLogFileRotation(
    every(2000000).bytes().withLogFileRetentionPolicy(of(7).days()),
  ));

Available on nest.land at https://nest.land/package/optic