ovx / sbsg-typescript-preprocessor

SBSG Typescript preprocessor

Creates Hapi's Joi validators from Typescript interface definitions.

Install

npm install
npm build # this is automaticly called on npm install

Usage

Put your TS interfaces to file(s) e.g. /path/to/interfaces.ts: Then transfer these TS definitions into Joi

import {exportTsDeclarations} from type 'typescript-preprocessor'

const definitions: string = exportTsDeclarations(['/path/to/interfaces.ts'])
...
// save definitions into file that you will load on your hapi server startup
...
import {JoiObject} from 'joi'
const joiDefinitions: JoiObject = await importTsDeclarationsToJoi(definitions)

Optionaly you can provide your own definitions for complex types

// let's assume there exist this interface
namespace myNamespace {
    interface myInterface {
        myProperty: string
    }
}

const customProperties: CustomProperties = {
    types: {
        [nameof.full<myNamespace.myInterface>() as string]: async () => Joi.string().lowercase().trim(),
    },
    modifiers: {
        [nameof.full<myNamespace.DefaultEmptyArray>() as string]: async (joiValidator) => joiValidator.default([])
    }
}

// then you can import definition and custom types like this
const joiDefinitions: JoiObject = await importTsDeclarationsToJoi(definitions, customProperties)

When using custom properties setup your types as basic validators and modifiers something that modifies them e.g. add default value. You can then use them in your interfaces like this

interface myInterface {
    myProperty: baseValidatorType & modifier1 & modifier2 & ...
}

TODO

• extend option of custom/virtual properties
  • type expressions (combining of types)
    • basic myType1 | myType2
    • complex with parentheses myType1 | myType2 | (myType3 & myType4)
  • expose defined custom properties for type expressions
    • this could(should?) reduce amount of virtual properties defined