Logging core | The Shelf

This package contains the definition of the logging operations. It uses a interchangeable driver system for performing the actual operations. A console, in-memory and void driver is included.

Installation

npm install @theshelf/logging

How to use

The basic set up looks like this.

import Logger, { MemoryDriver } from '@theshelf/logging';

const driver = new MemoryDriver();
const logger = new Logger(driver);

// Perform operations with the logger instance

Configuration

The logger has a configurable log level.

import { LogLevels } from '@theshelf/logging';

logger.logLevel = LogLevels.DEBUG; // default level

Operations

// Log debug
await logger.debug(message);

// Log info
await logger.info(message);

// Log warning
await logger.warn(message);

// Log error
await logger.error(message);

// Log fatal
await logger.fatal(message);

// Log multiple messages (works for all levels)
await logger.info(message1, message2, ...);

// Logging multiple types of values (works for all levels)
await logger.info('string', new Error('Oops...'), 42, [ 'a', 3.14 ], { name: 'John Doe', age: null });

Value interpretation

Currently, the logger has support for the following types of values:

• All primitive types
• Null / undefined
• Errors (its stack if available or else its message)
• Arrays (all values will be interpreted and concatenated with a space between them)
• Objects (will be stringified)

In case multiple messages are given, they will be concatenated with a space between them.

Drivers

There are three drivers included in this package. Other drivers are available in separate packages.

Void

Dummy driver that doesn't log anything (suited for testing). It doesn't have any configuration options or additional operations.

Memory

In memory logging (suited for testing). It doesn't have any configuration options, but has an additional operation.

// Clear the memory
driver.clear();

Console

Driver based on the Node.js console. It doesn't have any configuration options or additional operations.