@nik0605/dev-logger v1.0.0

Dev-Log

A simple, customizable logging library for Node.js applications. dev-logger supports multiple log levels, customizable formats, colored output, and custom log transports, making it ideal for development environments.

Installation

You can install dev-logger using npm:

npm install dev-logger

Usage

Once installed, you can require and configure the logger in your Node.js application.

Basic Usage

const Logger = require("dev-logger");

// Create a new Logger instance
const logger = new Logger({
  logFile: "path/to/your/logfile.log", // Optional: The log file location
  colors: {
    info: "cyan", // Custom color for 'info' logs
    warn: "magenta", // Custom color for 'warn' logs
    error: "red", // Custom color for 'error' logs
    debug: "gray", // Custom color for 'debug' logs
  },
});

// Log messages with different levels
logger.info("This is an info message");
logger.warn("This is a warning message");
logger.error("This is an error message");
logger.debug("This is a debug message");

Log Levels

• info: Informational messages (blue by default)
• warn: Warning messages (yellow by default)
• error: Error messages (red by default)
• debug: Debugging messages (green by default)

Each log level is color-coded by default for better readability. You can customize the colors and format as needed.

Custom Log Formats

You can customize the log format using the format option in the constructor. By default, the log format is:

{level}: {message} at {timestamp}

You can replace the format string with your custom format. For example, you can include additional information like the hostname, user ID, etc.

Example of Custom Format

const logger = new Logger({
  logFile: "path/to/your/logfile.log",
  format: "{level} - {message} at {timestamp} from {hostname}",
});

Custom Transport

You can also integrate the logger with external services (such as sending logs to a remote server) by using the customTransport option. Provide a custom transport that has a send method.

const logger = new Logger({
  logFile: "path/to/your/logfile.log",
  customTransport: {
    send: function (log) {
      // Send log to an external system, e.g., a remote logging server
      console.log("Sending log to external service:", log);
    },
  },
});

logger.info("This log will be sent to an external service");

JSON Logging

If you prefer to log in JSON format, you can use the logAsJson method. This is especially useful for log aggregation systems.

logger.logAsJson("info", "This is a JSON log entry");

Clear Logs

You can clear the log file using the clearLogs method. This is useful if you want to clear logs between runs or after a certain period of time.

logger.clearLogs();

Example: Full Configuration

const Logger = require("dev-log");

// Create a new Logger instance with all options
const logger = new Logger({
  logFile: "logs/app.log",
  rateLimit: 2000, // Log rate limiting in milliseconds
  format: "{level}: {message} at {timestamp} from {hostname}",
  colors: {
    info: "cyan",
    warn: "magenta",
    error: "red",
    debug: "green",
  },
  customTransport: {
    send: function (log) {
      // Send log to an external service (e.g., a monitoring system)
      console.log("Sending log:", log);
    },
  },
});

logger.info("Application started");
logger.error("An error occurred");
logger.debug("Debugging the app");

Features

• Multiple Log Levels: Supports info, warn, error, and debug log levels.
• Custom Log Formats: Fully customizable log format for timestamp, level, and message.
• Color-Coded Logs: Customizable colors for each log level.
• Custom Transport: Easily send logs to external systems or services.
• JSON Logging: Log entries can be written in structured JSON format.
• Clear Logs: Clears the log file if required.
• File-Based Logging: Logs are written to a specified file (defaults to test.log).

Installation

To install dev-logger, use the following npm command:

npm install dev-logger

API

new Logger(options)

Creates a new logger instance. The available options are:

• logFile (string): The path of the log file (default is test.log).
• rateLimit (number): The minimum time between log writes (default is 1000ms).
• format (string): A string to define the log message format. Available placeholders: {level}, {message}, {timestamp}, {hostname}.
• colors (object): Custom colors for each log level. Default is:

  {
    info: 'blue',
    warn: 'yellow',
    error: 'red',
    debug: 'green'
  }

• customTransport (object): A custom transport with a send method for sending logs externally.

Logger.info(message)

Logs an info-level message.

Logger.warn(message)

Logs a warning-level message.

Logger.error(message)

Logs an error-level message.

Logger.debug(message)

Logs a debug-level message.

Logger.clearLogs()

Clears the log file.

Logger.logAsJson(level, message)

Logs the message in JSON format.

License

MIT License