DyeLog

A simple (but colorful) logger for Deno.

Package URLs

JSR package: https://jsr.io/@littlelite/dyelog

Legacy Deno/X documentation: https://deno.land/x/dyelog

Constructor options

DyeLog accepts three options:

• timestamp: boolean
  • true: prepend a timestamp like 2026-03-12 11:08:17.278
  • false: print only level/message information
• printlevel: boolean
  • true: prepend the level label (TRACE, DEBUG, INFO, WARN, ERROR)
  • false: omit the level label from output
• level: LogLevel
  • minimum level to print
  • order is TRACE < DEBUG < INFO < WARN < ERROR
  • example: with LogLevel.INFO, trace/debug are ignored, while info/warn/error are printed

Default behavior (when no options object is passed):

const logger = new DyeLog({
  timestamp: true,
  printlevel: true,
  level: LogLevel.DEBUG,
});

Usage

import { DyeLog, LogLevel } from "jsr:@littlelite/dyelog";

const logger = new DyeLog({
  timestamp: true,
  printlevel: true,
  level: LogLevel.TRACE,
});

logger.trace("This is trace");
logger.info("This is info");
logger.warn("This is warn");
logger.debug("This is debug");
logger.error("This is error");

Runtime helpers

• logger.isEnabled(level) lets you check whether a level is active before doing expensive work.
• logger.traceLazy(() => value) (and debugLazy, infoLazy, warnLazy, errorLazy) evaluate the callback only when that level is enabled.

if (logger.isEnabled(LogLevel.DEBUG)) {
  logger.debug(`Heavy payload: ${JSON.stringify(hugeObject)}`);
}

logger.debugLazy(() => `Heavy payload: ${JSON.stringify(hugeObject)}`);

Lazy methods are useful in hot paths because disabled levels skip callback execution entirely.

Recommended usage patterns

• During development, use level: LogLevel.TRACE for maximum detail.
• In production-like scenarios, use level: LogLevel.INFO to reduce noise.
• For objects, prefer JSON.stringify(obj, null, 2) for readable output.
• Logging Error objects is supported (for example logger.error(err)).
• Use lazy methods (*Lazy) when creating log messages is computationally expensive.