# winston-log-space

> per-module wrapper over a winston v3 logger

Latest version **1.1.4** (published 2026-08-04) · MIT license · 0 weekly downloads

## Install

```sh
npm install winston-log-space
pnpm add winston-log-space
yarn add winston-log-space
bun add winston-log-space
```

## Health

**Score 55/100 (C)** — status: active.

Positive: no vulnerabilities; recently updated; high maintenance score.

Warnings: low downloads; no types; no esm support.

## Facts

| | |
|---|---|
| Version | 1.1.4 |
| Published | 2026-08-04 |
| First published | 2018-06-22 |
| Weekly downloads | 0 |
| License | MIT |
| TypeScript types | none |
| Module format | CommonJS |
| Dependencies | 3 |
| Unpacked size | 12.7 KB |
| Known vulnerabilities | 0 |
| Install scripts | no |
| Author | Jose Luis Martinez Juan |
| Maintainers | pepmartinez |
| Keywords | log, winston, module |

## Links

- npm: https://www.npmjs.com/package/winston-log-space
- Repository: https://codeberg.org/pepmartinez/winston-log-space
- Issues: https://codeberg.org/pepmartinez/winston-log-space/issues
- npm.io page: https://npm.io/package/winston-log-space

## Dependencies (3)

- [lodash](https://npm.io/package/lodash.md) ~4.18.1
- [winston](https://npm.io/package/winston.md) ~3.19.0
- [cascade-config](https://npm.io/package/cascade-config.md) ~1.9.2

## Alternatives

- [cli-color](https://npm.io/package/cli-color.md) — 3.4M weekly downloads
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- [@nocobase/plugin-logger](https://npm.io/package/@nocobase/plugin-logger.md) — 2.0K weekly downloads
- [child-process-debug](https://npm.io/package/child-process-debug.md) — 695 weekly downloads

## Recent versions

- 1.1.4 (latest) — 2026-08-04
- 1.1.3 — 2026-04-21
- 1.1.2 — 2025-08-19
- 1.1.1 — 2023-04-16
- 1.1.0 — 2023-04-16
- 1.0.7 — 2022-03-22
- 1.0.6 — 2021-05-13
- 1.0.5 — 2020-09-05
- 1.0.4 — 2020-07-17
- 1.0.3 — 2019-07-14
- 1.0.2 — 2019-02-12
- 1.0.1 — 2018-07-20
- 1.0.0 — 2018-06-28
- 0.0.1 — 2018-06-26
- 0.0.0 — 2018-06-22

## README

# winston-log-space
Per-module wrapper over a winston v3 logger

## Motivation
Winston is a great logger platform, but it lacks abilities to provide different *subloggers* with different loglevels, as one can find in, for example, log4j

Thus, I decided to see if such a thing would be easy to do on top of the freshly-released winston v3

## Structure
winston-log-space (wls henceforth) works in the following way:
* a single winston logger is created; it can have whatever transports as desired, and its *format* can also be specified. Its level will be set to *silly*
* a set of shallow, light loggers with the usual 'log()' and 'debug()/verbose()/info()... ' interface are created on demand, using a hierarchical module naming (separator is ':'). Each of this shallow loggers will have its own level and a simple check on it, so they will or will not cal the *root* winston logger depending on their level
* many aspects such as the associations of loglevels to name hierarchies are configurable via env vars, command line options or even js files

## Quick start
Let us have a `test.js` file:
```javascript
var Log = require ('winston-log-space');

Log.init ((err) => {
  if (err) return console.error(err)

  l1 = Log.logger ('s1');
  l2 = Log.logger ('s2:s3:s4');

  l1.info    ('this is l1 on info %s, %d', 'ggg', 666);
  l1.verbose ('this is l1 on verbose %s, %d', 'ggg', 666);

  l2.info    ('this is l2 on info %s, %d', 'ggg', 666);
  l2.verbose ('this is l2 on verbose %s, %d', 'ggg', 666);
});
```

then, running it with various command line options we get: 
```bash
$ node test.js 
2018-06-27T15:17:09.554Z [s1] info: this is l1 on info ggg, 666
2018-06-27T15:17:09.556Z [s2:s3:s4] info: this is l2 on info ggg, 666

$ node test.js --log__level__s1=debug
2018-06-27T15:17:12.331Z [s1] info: this is l1 on info ggg, 666
2018-06-27T15:17:12.333Z [s1] verbose: this is l1 on verbose ggg, 666
2018-06-27T15:17:12.333Z [s2:s3:s4] info: this is l2 on info ggg, 666

$ node test.js --log__level__s2=debug
2018-06-27T15:17:18.415Z [s1] info: this is l1 on info ggg, 666
2018-06-27T15:17:18.417Z [s2:s3:s4] info: this is l2 on info ggg, 666
2018-06-27T15:17:18.417Z [s2:s3:s4] verbose: this is l2 on verbose ggg, 666
```

Alternatively, we can use env vars:
```bash
$ LOG_level__s1=debug node test.js 
2018-06-27T15:19:39.274Z [s1] info: this is l1 on info ggg, 666
2018-06-27T15:19:39.276Z [s1] verbose: this is l1 on verbose ggg, 666
2018-06-27T15:19:39.277Z [s2:s3:s4] info: this is l2 on info ggg, 666

$ LOG_level__s2=debug node test.js 
2018-06-27T15:20:15.196Z [s1] info: this is l1 on info ggg, 666
2018-06-27T15:20:15.199Z [s2:s3:s4] info: this is l2 on info ggg, 666
2018-06-27T15:20:15.199Z [s2:s3:s4] verbose: this is l2 on verbose ggg, 666
```
## Configuration
All of the configuration magic inside `init()` is done using [cascade-config](https://github.com/pepmartinez/cascade-config), using the following config cascade:
* a `defaults` object
* the `opts` object passed as first param to `init()` if any
* env vars, with `prefix: LOG_`
* args, with `prefix: log.`
* contents of file `process.cwd() + '/log.js'`
* contents of file `process.cwd() + '/log-{env}.js'`
* contents of a file whose name is specified in config as `wlsconfig`

### using `init(opts, cb)`
As stated, you can inline your confi, or extra defults, by passing them to `init()`:
```javascript
var Log = require ('../');
var winston = require ('winston');


var config = {
  level: {
    s1: 'silly'
  },
  format: winston.format.combine(
    winston.format.timestamp(),
    winston.format.splat(),
    winston.format.printf(info => `${info.timestamp} | ${info.area} | ${info.level} | ${info.message}`)
  ),
  transports: [
    new winston.transports.Console(),
    new winston.transports.File({filename: 'test.log'})
  ]
};

Log.init (config, (err) => {
  if (err) return console.error(err)
  l1 = Log.logger ('s1');
  l2 = Log.logger ('s2:s3:s4');

  l1.info    ('this is l1 on info %s, %d', 'ggg', 666);
  l1.verbose ('this is l1 on verbose %s, %d', 'ggg', 666);

  l2.info    ('this is l2 on info %s, %d', 'ggg', 666);
  l2.verbose ('this is l2 on verbose %s, %d', 'ggg', 666);
});
```

This will get you:
```bash
$ node inline-config.js 
2018-06-28T06:23:02.817Z | s1 | info | this is l1 on info ggg, 666
2018-06-28T06:23:02.819Z | s1 | verbose | this is l1 on verbose ggg, 666
2018-06-28T06:23:02.820Z | s2:s3:s4 | info | this is l2 on info ggg, 666

$ cat test.log 
2018-06-28T06:23:02.817Z | s1 | info | this is l1 on info ggg, 666
2018-06-28T06:23:02.819Z | s1 | verbose | this is l1 on verbose ggg, 666
2018-06-28T06:23:02.820Z | s2:s3:s4 | info | this is l2 on info ggg, 666
```

### using files
Creating a `log.js` file in your PWD is also a way:
```javascript
var winston = require ('winston');

module.exports = {
  level: {
    s1: 'silly'
  },
  format: winston.format.combine(
    winston.format.timestamp(),
    winston.format.splat(),
    winston.format.printf(info => `${info.timestamp} | ${info.area} | ${info.level} | ${info.message}`)
  ),
  transports: [
    new winston.transports.Console(),
    new winston.transports.File({filename: 'test.log'})
  ]
};
```

so, running your js in the same directory:
```bash
$ node basic.js 
2018-06-28T06:25:56.812Z | s1 | info | this is l1 on info ggg, 666
2018-06-28T06:25:56.815Z | s1 | verbose | this is l1 on verbose ggg, 666
2018-06-28T06:25:56.815Z | s2:s3:s4 | info | this is l2 on info ggg, 666
```

### or, passing any file as config
You can also pass any file, not just `./log.js` as source for your config; simply specify anywhere in your config sources a key `wlsconfig` which should contain the filename (as an absolute path). For example, passing it via cli:
```bash
$ node basic.js --log__wlsconfig=$PWD/config-log.js
2018-06-28T06:29:15.413Z | s1 | info | this is l1 on info ggg, 666
2018-06-28T06:29:15.415Z | s1 | verbose | this is l1 on verbose ggg, 666
2018-06-28T06:29:15.416Z | s2:s3:s4 | info | this is l2 on info ggg, 666
```

---
_Source: https://npm.io/package/winston-log-space · Machine-readable twin of the npm.io package page. Health data is recomputed on every publish._