Daring Way Console Logger & Metrics

What it is

A drop-in logging module to enhance console.log() that provides the following:

• All logs and metrics in JSON format to STDOUT
• Metrics Logging
• Blazing fast high-performance non-blocking STDOUT writer (benchmark a million log events, 301M, in 2.3s)
• Handles formating javascript error

What it is not

• Not a framework
• Does not support log files

Quick Start

Add to your project

deno add jsr:@daringway/logger

For any App

In your applications entry point

import { initLogger } from "@daringway/logger";
initLogger();

Start logging with console.error, console.warn, console.log, console.info, and console.trace, it's that easy.

App Server Support

Preconfigured support for ExpressJS and Fresh V1 provides the following:

• Metrics (Request and Logger)
• Log Levels
• Trace Logging
• Metadata

ExpressJS Configuration

import { expressLoggerMiddleware, initLogger } from "@daringway/logger";
initLogger(backendConfig.logConfig);

const app: Express = express();

// Set this up first, it registers the logger onFinsih and starts the metrics timer
app.use(expressLoggerMiddleware());

Fresh V1 Configuration

In fresh.config.ts

import { freshV1LoggerPlugin, initLogger } from "@daringway/logger";

initLogger();

export default defineConfig({
  plugins: [
    tailwind(),
    freshV1LoggerPlugin(),
  ],
});

Request Context Information

export type RequestContext = {
  trace: {
    requestId: string;
    tracePath: string[];
    correlationId: string;
    sessionId: string;
  };
  client: {
    userAgent: string;
    applicationName: string;
    applicationVersion: string;
  };
  request: {
    method: string;
    path: string;
  };
  metrics?: MetricsTracker<never>;
};

Environment Variables

LOG_LEVEL: "error" | "warn" | "info" | "log" | "debug" | "trace" Sets the logging level. error and metrics will always log. Default: "log"

LOG_SECONDS_BETWEEN_METRICS: number Number of seconds between automatic metrics logging. Default: 500

LOG_OBJECTS: boolean Enable logging of full objects in trace logs. Use for WebStorm testing. Default: false

LOG_PRETTY: boolean Enable pretty printing of logs for development. Use for CLI testing. Default: false

LOG_WITH_CONSOLE: boolean Enable logging to console. Default: false, writes to STDOUT

Log Levels Explained

When logging use this as a guide on which level to log at.

0. metrics: Keeping tabs on the numbers and performance stats (always logged)
1. error: Uh-oh, something went wrong! Think of it like the 'outer safety net' catching unexpected surprises. (always logged)
2. warn: Heads up! Something is off, but we're still okay for now.
3. info: Just keeping you posted—things like the service starting up or shutting down.
4. log: Everyday chatter-like requests coming in and going out, nothing out of the ordinary.
5. debug: Developer-level love. The nitty-gritty details only developers adore.
6. trace: Super-detailed breadcrumbs—like tracking function calls or variable values.