Simple Logger

Simple Logger is a lightweight and easy-to-use logging library for Node.js applications. It provides a simple and intuitive way to log messages with different severity levels, format log messages, and rotate log files.

Installation

To install Simple Logger, use npm:

npm install simplest-fancy-logger

Usage

First, require the SimpleLogger class in your Node.js application:

import SimpleLogger from "simplest-fancy-logger"

Then, create an instance of the SimpleLogger class with the desired configuration options:

const logger = new SimpleLogger({
  logLevel: "debug",
  logFile: "app.log",
  logFormat: "[{level}] [{timestamp}] - {message} - {emoji}",
  dateFormat: "yyyy-mm-dd HH:MM:ss",
  maxFileSize: 1024 * 1024 * 5, // 5MB
  maxFiles: 3,
})

Now you can use the logger instance to log messages with different severity levels:

logger.info("This is an informational message")
logger.warn("This is a warning message")
logger.error("This is an error message")
logger.debug("This is a debug message")

The log messages will be outputted to the console and written to the specified log file.

Output Examples

Here are some examples of how the log messages will be outputted using Simple Logger:

The log messages include the following components:

• Log Level: The severity level of the message, displayed in uppercase and colored based on the level.
• Timestamp: The timestamp of when the log message was generated, formatted according to the dateFormat configuration option.
• Message: The actual log message.
• Emoji: An emoji corresponding to the log level, providing a visual indication of the message severity.

The log messages will be outputted to the console and written to the specified log file (if configured) in the same format.

Configuration Options

The SimpleLogger class accepts the following configuration options:

• logLevel (string, default: 'info'): The minimum severity level of messages to log. Can be one of 'error', 'warn', 'info', or 'debug'.
• logFile (string, default: null): The path to the log file. If not specified, logs will only be outputted to the console.
• logFormat (string, default: '[{level}] [{timestamp}] - {message} - {emoji}'): The format of the log messages. You can use placeholders {level}, {timestamp}, {message}, and {emoji} to customize the format.
• dateFormat (string, default: 'yyyy-mm-dd HH:MM:ss'): The format of the timestamp in log messages.
• maxFileSize (number, default: 1024 * 1024 * 10): The maximum size (in bytes) of the log file before it gets rotated.
• maxFiles (number, default: 5): The maximum number of rotated log files to keep.

Log Levels

Simple Logger supports the following log levels, in decreasing order of severity:

• error: Error messages.
• warn: Warning messages.
• info: Informational messages.
• debug: Debug messages.

Log File Rotation

Simple Logger automatically rotates the log file when it reaches the specified maximum size. The rotated log files are named with a numbered suffix (e.g., app.log.1, app.log.2, etc.). The number of rotated log files is limited by the maxFiles configuration option.

License

Simple Logger is released under the MIT License.