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node-json-logger

Simply, output logs to STDOUT in JSON

Install

``sh
npm i node-json-logger
`

Usage

`js
const Logger = require('node-json-logger');
const logger = new Logger();

logger.info();
logger.info('message');
logger.info('message','message','message');
logger.info({ data: 'data' });
logger.info({ data1: 'data' }, { data2: 'data' });
logger.info('message', { data1: 'data' }, 'message', { data2: 'data' }, 'message');
`

Outputs:

`json
{"timestamp":"2001-03-14T01:00:00.000Z","level":"info"}
{"timestamp":"2001-03-14T01:00:00.000Z","level":"info","message":"message"}
{"timestamp":"2001-03-14T01:00:00.000Z","level":"info","message":"message","message1":"message","message2":"message"}
{"timestamp":"2001-03-14T01:00:00.000Z","level":"info","data":"data"}
{"timestamp":"2001-03-14T01:00:00.000Z","level":"info","data1":"data","data2":"data"}
{"timestamp":"2001-03-14T01:00:00.000Z","level":"info","message":"message","data1":"data","message1":"message","data2":"data","message2":"message"}
`

API

`js
logger.xxx(message?, ...)
`

Note:

* xxx is one of the Levels

Arguments:

* message: Specify a message as string or object.

Levels

* trace
* debug
* info
* warn
* error
* fatal

Configuration

$3

Specify output level. (optional, default is debug)

`js
const Logger = require('node-json-logger');
const logger = new Logger({ level: 'error'});

logger.trace('message');
logger.debug('message');
logger.info('message');
logger.warn('message');
logger.error('message');
logger.fatal('message');
`

Output:

`json
{"timestamp":"2001-03-14T01:00:00.000Z","level":"error","message":"message"}
{"timestamp":"2001-03-14T01:00:00.000Z","level":"fatal","message":"message"}
`

Level and output:

| | trace | debug | info | warn | error | fatal |
|:---------------------|:------|:------|:-----|:-----|:------|:------|
| { level: 'trace' } | O | O | O | O | O | O |
| { level: 'debug' } | - | O | O | O | O | O |
| { level: 'info' } | - | - | O | O | O | O |
| { level: 'warn' } | - | - | - | O | O | O |
| { level: 'error' } | - | - | - | - | O | O |
| { level: 'fatal' } | - | - | - | - | - | O |
| { level: 'none' } | - | - | - | - | - | - |

$3

Specify the name of the logger. Useful when logging from different files.

`js
const Logger = require('node-json-logger');
const logger = new Logger({ loggerName: 'server/index.js' });

logger.info('message');
`

Output:

`json
{"timestamp":"2001-03-14T01:00:00.000Z","level":"info","loggerName":"server/index.js","message":"message"}
`

$3

Specify enable or disable timestamp. (optional, default is true)

`js
const Logger = require('node-json-logger');
const logger = new Logger({ timestamp: false });

logger.info('message');
`

Output with disabled timestamp:

`json
{"level":"info","message":"message"}
`

$3

Specify locale timezone. (optional, default is UTC)

`js
const Logger = require('node-json-logger');
const logger = new Logger({timezone: 'America/Sao_Paulo'});

logger.info('message');
`

Output with specific timezone:

`json
{"timestamp":"2018-10-25T15:32:43.318Z","level":"info","message":"message"}
`

Same output with default timezone (UTC):

`json
{"timestamp":"2018-10-25T18:32:43.318Z","level":"info","message":"message"}
``

Click here to see the list with all available timezones.

License

MIT

Copyright ©2018 Hiroaki SHIBUKI a.k.a. hidori