Welcome to Tamam!

The motive behind this library is to enable validating properties of TS classes using the TS experimental decorators.

Setup

To add validation to your typescript class, simply add the @v decorator before your class. this will in turn populate a local map inside your class named v of type TValidationMap

To validate a property: use the validatorFactory before your property, this can be composed as you wish.

// import the factory
import { validatorFactory } from  'tamam';

//define a not validator..
const not = (param:  number) =>
    validatorFactory({
        not: (val:  number) => {
            const  isOk  =  val  !=  param
            return { isOk, message:  isOk  ?  ''  :  `validation.not.error` }
        },
        // you can use as many validator functions here..
    })

// following is a parameterless decorator..
const positive = validatorFactory({
        positive: (val:  number) => {
            const  isOk  =  val  >0
            return { isOk, message:  isOk  ?  ''  :  `validation.positive.error` }
        },
        //...other validation functions if needed
    })

import {v} from 'tamam'
@v
class Human {
     // the lib will auto-add the following local v prop (not required) , but can enhance intellisense
     v!:  TValidationMap<Human ,'not'|'positive'>

     // you can appply more than one validator here..
     // age is valid if not n
     @not(10) // with param
     @positive // parameterless..
     age!:number
    //...
}

Note: In your ts-config make sure to enable the experimental decorators.

Typing

To acquire information about your validation map, you can add a local property to your class named v of TValidationMap type

@v
class Human {
v!:  TValidationMap<Human ,'not'|'positive'>
//...
}

The validation map will contain information about properties marked with validators as follows:

const someone = new Human()
someone.age = -10
console.log(someone.v.age.result) // specific prop v info
console.log(someone.v) // the full v map