megasniff: Debugging promise-chains for humans
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Megasniff
Better debugging for chained functions (promises, streams, etc.). Inspired by supersniff , but with these improvements in mind:
- Support for custom loggers (like bunyan , winston , or other services)
-
No forced
tag
- Using error levels for errors
Things to do:
- Custom configureable log levels
-
Decorator functions (e.g.
error => error.message
)
Motivation
Can be found here . It shall be a readable replacement for:
getData() .then(data => { console.info(data) return data }) .then(transformData)
Installation
npm install megasniff
Examples
const megasniff = require('megasniff') const reveersedList = new Promise(resolve => resolve([3, 1, 2])) .then(megasniff) .then(list => list.sort()) .then(megasniff) .then(list => list.reverse()) .then(megasniff)
This yields in the console:
[ 3, 1, 2 ] [ 1, 2, 3 ] [ 3, 2, 1 ]
const megasniff = require('megasniff') new Promise(resolve => resolve('Good')) .then(megasniff.config({ suffix: `Value at ${new Date()}:` }))
This yields on stdout:
Good Value at Wed Oct 17 2018 15:47:26 GMT+0200 (Central European Summer Time)
const megasniff = require('megasniff') const logger = console new Promise((resolve, reject) => reject(new Error('Bad'))) .catch(megasniff.config({ suffix: '.. We are doomed' })) .catch(error => error)
This yields on stderr:
Error: Bad ... We are doomed
API
Default Usage:
const megasniff = require('megasniff') const sortedList = new Promise(resolve => resolve([3, 1, 2])) .then(megasniff) .then(list => list.sort()) .then(megasniff)
megasniff
is a function that logs and returns the passed value.
The value is logged either to stdout or sterr depending on the passed value.
Configuration:
const megasniff = require('megasniff') const logger = console new Promise(resolve => resolve('Good Software')) .then(megasniff.config({ prefix: `[megasniff]`, logger }))
megasniff.config
takes an object as argument.
Megasniff can be configured with these optional parameters:
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