Usage example for final-form-set-field-data.

final-form-set-field-data-usage.js

import { createForm } from 'final-form'
import setFieldData from 'final-form-set-field-data'

// Create Form
const form = createForm({
  mutators: { setFieldData },
  onSubmit
})

form.mutators.setFieldData('firstName', { awesome: true })

form.registerField(
  'firstName',
  fieldState => {
    const { awesome } = fieldState.data // true
  },
  {
    // ...other subscription items
    data: true
  }
)