@jameslnewell/logger

A logging library.

Installation

yarn add @jameslnewell/logger

Usage

Using a logger

import logger from '@jameslnewell/logger';

logger.info('Server is listening on http://localhost:3000');

Using an extended logger

import logger from '@jameslnewell/logger';

const log = logger.extend('my-server');

log.info('Server is listening on http://localhost:3000');

Adding the time to the logs

import logger, {time} from '@jameslnewell/logger';

logger.use(time());

Adding the version to the logs

import logger, {version} from '@jameslnewell/logger';

logger.use(version());

Adding a custom field to the logs

import logger from '@jameslnewell/logger';

logger.use(log => ({...log, foo: 'bar'}));

Filtering the logs

import logger, {Level, filter} from '@jameslnewell/logger';

logger.use(filter(log => log.level === Level.error));

Writing logs to the console

import logger, {ConsoleOutputStream} from '@jameslnewell/logger';

logger.pipe(new ConsoleOutputStream());

Writing logs to a file

import logger, {FileOutputStream} from '@jameslnewell/logger';

logger.pipe(new FileOutputStream());

Writing logs to a file on error

import logger, {MemoryOutputStream} from '@jameslnewell/logger';

const logs = logger.pipe(new MemoryOutputStream());
try {
  // do stuff here
} catch (error) {
  logger.error(error);
  fs.WritingFileSync('app.log', logs);
}

Writing logs to CloudWatch

import logger, {CloudwatchOutputStream} from '@jameslnewell/logger';

logger.pipe(new CloudwatchOutputStream({
  group: 'my-group',
  stream: 'my-stream',
}));