Form Filling

Functions for filling form fields using native property setters. Import from @snapfill/core.

fillForm(fieldMap, mappings)

function fillForm(
  fieldMap: Map<string, HTMLElement>,
  mappings: AutofillMappings
): FillResult

Fills form fields using a field map from scanForFields.

Parameters:

• fieldMap — Map of field type strings to DOM elements
• mappings — Object mapping field types to values

Returns: FillResult with counts of filled/total fields and a list of failed field names

import { scanForFields, fillForm } from '@snapfill/core';

const { fieldMap } = scanForFields();

const result = fillForm(fieldMap, {
  firstName: 'Jane',
  lastName: 'Doe',
  email: 'jane@example.com',
  postalAddressLine1: '123 Main St',
  postalState: 'NY',
  postalPostCode: '10001',
});

console.log(`Filled ${result.filled} of ${result.total}`);
console.log('Failed:', result.failed);

fullName Synthesis

If the form has a fullName field but your mappings don't include one, fillForm automatically synthesizes it from firstName, middleName, and lastName:

fillForm(fieldMap, {
  firstName: 'Jane',
  middleName: 'Marie',
  lastName: 'Doe',
});
// If fieldMap has 'fullName', it gets filled with "Jane Marie Doe"

An explicit fullName in the mappings is never overwritten.

fillElement(element, value)

function fillElement(element: HTMLElement, value: string): void

Fills a single element with the appropriate strategy based on its type:

• <input> / <textarea> — Uses native property setter, dispatches focus → input → change → blur
• <select> — Matches by value, then text, then partial text
• Checkbox / Radio — Sets checked based on value ("true", "1", "yes", "on")

const input = document.getElementById('email');
fillElement(input, 'jane@example.com');

Does nothing if element or value is falsy.