Create typescript interface based on a const defaultValues map

Question

I wanted to do some something similar to this: https://stackoverflow.com/a/45777530/565877

But I'm not working with any sort of real database schema, I just have a simple object of field names and their default values, like so:

export const FormFieldDefaults = {
  firstName: '',
  lastName: '',
  dateOfBirth: ''
}

I want to generate this respective type:

export type FormFields = {
  firstName: string
  lastName: string
  dateOfBirth: string
}

Devin Rhode · Accepted Answer · 2020-11-10 23:22:36Z

1

Turns out all we need is the typeof type operator:

export const FormFieldDefaults = {
  firstName: '',
  lastName: '',
  dateOfBirth: ''
}

export type FormFields = typeof FormFieldDefaults

answered Nov 10, 2020 at 23:22

Devin Rhode

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