How to create an optional field type while creating io-ts types

[sravanmca21]

Hi ,

Could you please help me in how to create an optional field while creating io-ts types
for e.g. in below code "contact" type , how to make addressDetails as an optional field like typescript optional field with (?)

import * as t from 'io-ts'

export const address = t.type({
addressline1: t.string,
city: t.string
countryName: t.string
})

export const email = t.type({
emailId: t.string,
})

export const phone= t.type({
number: t.string,
extn: t.string
})

export const contact = t.type {
addressDetails: address, // need to make only addressDetails as an optional field
email: email, // need this as required
phone: phone // need this as required
})

[david-zacharias]

You can use an intersection

export const contact = t.intersection([
  t.partial({
    addressDetails: address
  }),
  t.type({
    email,
    phone
  })
])

export type contact = t.TypeOf<typeof contact>

See also docs