io-ts-derive-class

Getting Started

yarn add io-ts-derive-class io-ts

Purpose:

This library is intended to help create classes from io-ts interface types and assist in setting defaults on instances of these classes.

Quick Example:

    import * as t from 'io-ts'
    import * as tdc from 'io-ts-derive-class'

    //Define a normal io-ts interface type
    const CityType = t.type({
        ID: t.number,
        Name: t.string
    })

    //Derive a class from it
    class City extends tdc.DeriveClass(CityType) {}

    //Define another io-ts interface type
    const AddressType = t.type({
        StreetAddress1: t.string,
        StreetAddress2: t.string,
        //Reference the previously defined class
        City: tdc.ref(City)
    });

    class Address extends tdc.DeriveClass(AddressType) {}

    const PersonType = t.type({
        ID: t.number,
        FirstName: t.string,
        //MiddleName is string or null.  The default generated will be the right most member of the union.  Here it will be null.
        MiddleName: t.union([t.string, t.null]),
        LastName: t.string,
        Address: tdc.ref(Address)
    });

    class Person extends tdc.DeriveClass(PersonType) {}

    const person = new Person({ 
        FirstName: 'Test', 
        LastName: 'TestLast'
    });

    //person.MiddleName === null
    //person.FirstName === 'Test'
    //person.Address.StreetAddress1 === ''
    //person.Address.City.Name === ''

    const personJson = JSON.stringify(person);
    const result = tdc.decode(Person, personJson);

    //result.isLeft() === false
    const areEqual = JSON.stringify(result.value) === personJson
    //areEqual === true

Derived Defaults:

• unions will always default to the right most type

  Type	Default Value
  t.number	0
  t.string	''
  t.undefined	undefined
  t.null	null
  t.boolean	false
  t.literal('myliteral')	'myliteral'
  t.union([t.string, t.undefined])	undefined
  t.union([t.string, t.null])	null
  t.union([t.number, t.string])	''
  t.type({})	{}
  t.tuple([t.string, t.number])	['', 0]
  t.array(arraytype)	[]
  tdc.ref(MyClass)	new MyClass()
  tdc.DateTime	moment()
  tdc.uuid	creates uuid4

More examples and tests can be found in src/index.spec.ts

Contributing:

yarn install
yarn run test