class-schema

class-schema is a library intended to extract from javascript class, the corrispondent JSON Schema, usually, the schema is written by hand or throught some tool that create the schema. but, with this library you can extract the schema directly from the class you defined, so you have a single source of truth of the schema SSOT that is your class.

:package: Installation

npm install class-schema

to use class-schema you also need the package reflect-metadata

npm install reflect-metadata

:rocket: Usage

Javascript

In order to use decorators in javascript, a transpiler that can

npm i -D babel-cli

TypeScript

You need to enable experimentalDecorators and emitDecoratorMetadata in your tsconfig.json

// file: tsconfig.json
{
  compilerOptions: {
    experimentalDecorators: true,
    emitDecoratorMetadata: true,
  },
}

in your index you have to import reflect-metadata

import 'reflect-metadata'

and you are ready to go!

:chart_with_upwards_trend: Examples

import 'reflect-metadata'
import { use, schema, prop, ref, enums } from 'class-schema'

const vowels = ['a', 'e', 'i', 'o', 'u', 'y']
type Vowels = typeof vowels[number]

@schema()
class MyObject {
  @enums(vowels)
  myEnum: Vowels
}

@schema()
class MySchema {
  @prop()
  myProp: number

  @array()
  @prop(Number)
  myPropArray: number[]

  @ref(MyObject)
  myObject: MyObject
}

to get javascript object that represent jsonschema of class use(MySchema)

// output of `JSON.stringify(use(MySchema))
{
  type: 'object',
  properties: {
    myProp: {
      type: 'number',
    },
    myPropArray: {
      type: 'array',
      items: {
        type: 'number',
      },
    },
    myObject: {
      type: 'object',
      properties: {
        myEnum: {
          type: 'array',
          items: {
            type: 'string',
            enum: ['a', 'e', 'i', 'o', 'u', 'y'],
          },
        },
      },
      required: ['myEnum'],
    },
  },
  required: ['myProp', 'myPropArray', 'myObject'],
}

:toolbox: Summary

:arrow_forward: use

:books: Documentation

Full Documentation

:label: License

MIT