@hyperflake/logger

A simple Node.js logger module for logging messages with flexible & customizable transports.

Installation

npm install @hyperflake/logger

Usage

import { Logger, transports } from '@hyperflake/logger';

// Create a logger instance with a transport configuration
const logger = new Logger({
    transports: [
        new transports.Console(),
        new transports.MongoDB({
            uri: 'mongodb://localhost/logging',
            collectionName: 'app-logs',
        }),
    ],
});

// Log an info message
logger.log({
    message: "This is an info message",
});

// Log an error message
logger.error({
    message: "This is an error message",
});

// Log a warning message
logger.warn({
    message: "This is a warning message",
});

API

Logger

Constructor

new Logger<TLoggerData>(options: LoggerOptions);

Creates a new logger instance with the specified transport configuration.

• options: Logger options.
  • transports: Array of transports to be used for logging.

Methods

• log(entry: LogEntry): void: Logs an info message.
• error(entry: LogEntry): void: Logs an error message.
• warn(entry: LogEntry): void: Logs a warning message.

Transports

Console Transport

A transport that logs messages to the console.

new transports.Console(options?: ConsoleTransportOptions);

• options: Options for the console transport.
  • formatterFn: (data: LogEntry<TLoggerData>) => string Function that formats log data into a string before outputting it to the console. (Optional).

MongoDB Transport

A transport that logs messages to MongoDB.

new transports.MongoDB(options: MongoDBTransportOptions);

• options: Options for the MongoDB transport.
  • uri: MongoDB connection URI.
  • dbName: Name of the MongoDB database. Defaults to DB name based on connection URI if not provided. (Optional)
  • collectionName: Name of the collection to store logs.
  • capped: Whether to create the log collection as capped or not. Defaults to true. (Optional)
  • cappedSize: Size of logs capped collection in bytes. Defaults to 10,000,000. (Optional)
  • cappedMax: Size of logs capped collection in number of documents. (Optional)

Example

import { Logger, transports } from '@hyperflake/logger'

// Create a logger instance with console transport & additional data type
const consoleLogger = new Logger<{ userId: number }>({
    transports: [
        new transports.Console(),
    ],
});

// Log a message with additional data
consoleLogger.log({
    message: "This is a log message",
    userId: 100001,
});

// Create a logger instance with custom formatterFn
const customizedConsoleLogger = new transports.Console({
    formatterFn: (data) => {
        return `[${data.timestamp.toString()}] ${data.level} - ${data.message}`;;
    } 
});

// This is the default formatterFn in case no formatterFn is passed
const defaultFormatterFn = (data: LogData<TLoggerData>) => {
    return JSON.stringify(data);
}

// Create a logger instance with MongoDB transport
const mongoLogger = new Logger<{ token: string }>({
    transports: [
        new transports.MongoDB({
            uri: 'mongodb://localhost/logging',
            collectionName: 'app-logs',
        }),
    ],
});

// Log a message with additional data
mongoLogger.log({
    message: "This is a log message",
    token: '0wq4kWuo63DJaCmLC',
});

// Create a mongodb logger instance with custom options
const customizedMongoLogger = new Logger<{ token: string }>({
    transports: [
        new transports.MongoDB({
            uri: 'mongodb://localhost',
            dbName: 'logging',
            collectionName: 'app-logs',
            capped: true, // Defaults to true,
            cappedSize: 1024 * 1024,
            cappedMax: 100000 
        }),
    ],
});