https://github.com/ahiipsa/zerg
lightweight logging library
https://github.com/ahiipsa/zerg
debugger debugging-tool developer-tools javascript logger nodejs zerg
Last synced: about 1 year ago
JSON representation
lightweight logging library
- Host: GitHub
- URL: https://github.com/ahiipsa/zerg
- Owner: ahiipsa
- Created: 2016-07-08T06:47:34.000Z (almost 10 years ago)
- Default Branch: master
- Last Pushed: 2022-02-13T12:05:45.000Z (over 4 years ago)
- Last Synced: 2025-04-09T07:03:46.379Z (about 1 year ago)
- Topics: debugger, debugging-tool, developer-tools, javascript, logger, nodejs, zerg
- Language: TypeScript
- Size: 309 KB
- Stars: 12
- Watchers: 2
- Forks: 2
- Open Issues: 4
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
Awesome Lists containing this project
README
[](https://travis-ci.org/ahiipsa/zerg)
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[](https://www.npmjs.com/package/zerg)
# Zerg
Lightweight logging library for apps and libs
## Futures
- Zero dependencies
- TypeScript support
- Easy to use
- Custom listeners/transports
- Support Node.js and Browsers
## Getting started
### Installation
`npm i --save zerg`
or
`yarn add zerg`
### Usage
Make module `logger.js`:
```js
import zerg from 'zerg';
import {
consoleNodeColorful,
consoleBrowserColorful,
} from 'zerg/dist/transports';
const logger = zerg.createLogger();
// Add console logger
const listener = zerg.createListener({
handler: consoleBrowserColorful, // for browser
// handler: consoleNodeColorful, // for node
});
logger.addListener(listener);
export default logger;
```
Make your module and import `logger.js`:
```js
import logger from './logger';
const log = logger('moduleName');
log.verbose('verbose message');
log.debug('debug message');
log.info('info message');
log.warn('warn message');
log.error('error message', {foo: 'bar'});
```
Result:
## API
### Types
```
type TExtendedData = Record;
```
```
type TLogMessage = {
timestamp: number;
loggerName: string;
moduleName: string;
level: TLogLevel;
message: string;
extendedData?: TExtendedData
};
```
```
type LogLevel = 'verbose' | 'debug' | 'info' | 'warn' | 'error';
```
```
type Listener = (log: TLogMessage) => void;
```
### zerg.createLogger(): Logger - Create logger instance
### zerg.createListener(params): LogListener - Create listener for logger
- params.handler: (logMessage: TLogMessage) => void;
- params.filter?: (logMessage: TLogMessage) => boolean; (optional)
- params.levels?: LogLevel; (optional)
### logger.addListener(listener: LogListener)
```js
import zerg from 'zerg';
const logger = zerg.createLogger();
const listener = zerg.createListener({
handler: (logMessage) => console.log(logMessage),
levels: ['info'], // listen only `info` level
});
logger.addListener(listener);
logger.module('myModule').info('Info message', {foo: 'bar'});
logger.module('myModule').warn('Warn message', {bar: 'baz'});
logger.module('myModule').error('Error message');
/* console
{
timestamp: 1467967421933,
level: 'info',
moduleName: 'myModule',
message: 'Info message',
extendedData: {foo: 'bar'},
}
*/
```
Use filter - Listen messages only from "Sarah" module
```js
import zerg from 'zerg';
const logger = zerg.createLogger();
const listener = zerg.createListener({
handler: (logMessage) => console.log(logMessage),
filter: (logMessage) => logMessage.moduleName === 'Sarah', // listen messages only from "Sarah" module
// levels: [], // at this case levels are ignoring
});
logger.addListener(listener);
logger.module('Alice').info('Info message', {foo: 'bar'});
logger.module('Bob').warn('Warn message', {bar: 'baz'});
logger.module('Sarah').error('Error message');
/* console
{
timestamp: 1467967421933,
level: 'info',
moduleName: 'myModule',
message: 'Info message',
extendedData: {foo: 'bar'},
}
*/
```
### removeListener(LogListener): void;
### removeAllListeners(): void;
### module(moduleName: string): LoggerModule;
### getModule(moduleName: string): LoggerModule | null;
### getModules(): Record;
## Other Examples
### [Sentry](http://sentry.io) transport
```js
import zerg from 'zerg';
const logger = zerg.createLogger();
const SENTRY_LEVEL_MAP = {
info: 'info',
warn: 'warning',
error: 'error',
fatal: 'error',
};
function sentryTransport(logMessage) {
const level = SENTRY_LEVEL_MAP[logMessage.level];
Sentry.withScope((scope) => {
scope.setLevel(level);
Object.keys(logMessage.extendedData).forEach((key) => {
scope.setExtra(key, logMessage.extendedData[key]);
});
scope.setTag('module', logMessage.moduleName);
Sentry.captureMessage(logMessage.message);
});
}
const listener = zerg.createListener({handler: sentryTransport});
logger.addListener(listener);
```
### Remote debug transport
It is be useful for debug when browser (or device) doesn't provide tool: Android with default browser, WinPhone, SmartTV.
At browser:
```js
import zerg from 'zerg';
const logger = zerg.createLogger();
function remoteTransport(logMessage) {
const req = new XMLHttpRequest();
req.open('POST', 'http://myhost.com:3000/log', false);
req.setRequestHeader('Content-type', 'application/json');
req.send(JSON.stringify(logMessage));
}
const listener = zerg.createListener({handler: remoteTransport});
logger.addListener(listener);
```
_Don't forget, host (http://myhost.com:3000/log) must be reachable from device._
At server you may use [express](https://www.npmjs.com/package/express):
```js
const express = require('express');
const bodyParser = require('body-parser');
const app = express();
app.use(bodyParser.json()); // for parsing application/json
app.post('/log', (req, res) => {
console.log(req.body);
});
app.listen(3000);
```