A simple Logger helper for Node.js

logger is a straightforward logger written in TypeScript. It logs to a single predefined file. When an option {tee: true} is given, logger shows colored messages in the console. If a log file is not defined, logger writes to the console only.

Homepage: https://github.com/popovmp/logger

Color outputs

Installation

npm install @popovmp/logger

Usage

import {initLogger, logError, logSuccess, logWarning} from "@popovmp/logger";

// Initialize logger
const loggerOptions = {
  filepath: "my/logger/path/log.txt",
  tee     : true,
  suppress: ["debug"],
};

initLogger(loggerOptions);

Examples

logInfo("Hello, World!");                           // => 2020-08-21 06:21:11 [INFO] Hello, World!
logInfo("GET index", "app::router");                // => 2020-08-21 06:21:11 [INFO] [app::router] GET index
logError("Ohh!", "bank::delete-account");           // => 2020-08-21 06:21:11 [ERROR] [bank::delete-account] Ohh!
logError(new Error("Err!"), "mission :: critical"); // => 2020-08-21 06:21:11 [ERROR] [mission :: critical] Err!
logText("So Long, and Thanks for All the Fish!");   // => So Long, and Thanks for All the Fish!

Last error

logger has two methods for getting and resetting the last logged error message: getLastError and resetLastError.

getLastError returns the last logged error message by the logError or logger.error methods.

You can reset the last error with the resetLastError method. When resetLastError is called without parameters, it sets the last error to undefined. resetLastError can be called with null to set the last error to null.

getLastError(); // undefined
logError("some eror");
getLastError(); // some error
resetLastError();
getLastError(); // undefined

Options

The filepath option sets the log filepath.

The init method accepts an options options parameter. It has two property tee: boolean and suppress: string[].

When tee is set to true, the logger doubles the message on the console.

The suppress parameter accepts a string[]. It suppresses the logging of the tags included.

The possible values are:

{
  "suppress": ["debug", "text", "info", "error", "success"]
}

Methods

logger exports the following methods:

/**
 * @param {LoggerOptions} loggerOptions
 * @returns {void}
 */
initLogger(loggerOptions);

/**
 * Logs a debug message to a log file
 *
 * @param {Error|object|string} message
 * @param {string} [sender]
 */
logDebug(message, sender);

/**
 * Logs a message to a log file
 *
 * @param {Error|object|string} message
 * @param {string} [sender]
 */
logInfo(message, sender);

/**
 * Logs an error to a log file
 *
 * @param {Error|object|string} message
 * @param {string} [sender]
 */
logError(message, sender);

/**
 * Logs a success message to a log file
 *
 * @param {string} message
 * @param {string} [sender]
 */
logSuccess(message, sender);

/**
 * Logs a text message
 *
 * @param {string} message
 */
logText(message);

/**
 * Gets the last logged error message
 *
 * @returns {Error|object|string|undefined|null}
 */
getLastError();

/**
 * Resets the last error
 *
 * @param {Error|object|string|undefined|null} [value]
 */
resetLastError(value);

/**
 * Resets logger options for testing purposes
 */
resetLogger();

License

logger is free for use and modification. No responsibilities for damages of any kind.