issable

>Issable -- Your Swiss Army Knife for runtime payload sanitisation and type-checking. Provides actionable error messges out-of-the-box.

There should be no learning curve for runtime payload sanitisation and type-checking. Issable is lightweight, readable, and highly extensible.

Installation

``
npm install --save issable
`

Usage

`ts
import { is } from 'issable'

is('foo').string() // returns true
is('foo').boolean() // Throws an error
`
Also supports CommonJS Require
`js
const { is, not, define } = require('issable')
`

Intuitive style (ExpressJS and Fastify compatible)


Do away with vague, or troublesome error messaging/handling. One-size-fit-all example in using Issable with ExpressJS/Fastify:
`ts

app.get('/', (req, res, next) => {
const payload = req.body
const schema = {
name: 'string',
age: 'number',
mobile: ['string', 'number']
}

const sanitised = is(payload)
.exact()
.statusCode(400) // Error instance will contain property statusCode. See #errorHandler, error.statusCode below.
.object(schema) // throws error if not matched, with details on mismatch with schema.

// if check is passed, sanitised contains the sanitised object for use
doSomethingWithPayload(sanitised)
})

// the above error will throw into Express/Fastify's error handler:
app.use(errorHandler)

function errorHandler(err, req, res) {
res.statusCode = (error.statusCode) ? error.statusCode : 500

res.locals.message = err.message
res.locals.error = err

res.send({
success: false,
...res.locals
})
}
`

Simple checks, and you can define our own error message:
`ts
function simpleAPIChecks(stringPayload, arrayPayload) {

is(stringPayload, 'nameOfString')
.msg('Invalid string.') // custom error message.
.string()

is(stringPayload, 'nameOfArray')
.msg('Invalid array.')
.string()

})
`

Define your custom type

`ts
import { define } from 'issable'

define({
nameOfTyping: 'currency',
primitives: ['string', 'number'], // could be string like '$10.00'

// a function to return true or false
toPass: (candidate: any) => {

// $10.00, remove '$', check if can be parsed to a float.
if (typeof candidate === 'string') {
candidate = candidate.replace('$', '')
return is(parseFloat(candidate)).safe().number()
}

// will be a number here, therefore will pass.
return true
},
})
})
`

#not

`ts
is(stringVar).not().boolean() // true

// is equivalent to

import { not } from 'issable'

not(stringVar).boolean() // true
not(stringVar).string() // throws error
``