@dwp/govuk-casa/src/lib/validators/required.js

A framework for building GOVUK Collect-And-Submit-Applications

import lodash from "lodash";
import { isEmpty, isStringable, stringifyInput } from "../utils.js";
import ValidatorFactory from "../ValidatorFactory.js";
import ValidationError from "../ValidationError.js";

const { isPlainObject } = lodash; // CommonJS

/**
 * @typedef {import("../../casa").ErrorMessageConfig} ErrorMessageConfig
 * @access private
 */

/**
 * @typedef {object} RequiredConfigOptions
 * @property {ErrorMessageConfig} errorMsg Error message config
 */

/**
 * Test if value is present.
 *
 * Value is required. The following values will fail this rule: (all values that
 * satisfy `isEmpty()`) plus '\s'
 *
 * See {@link RequiredConfigOptions} for `make()` options.
 *
 * @memberof Validators
 * @augments ValidatorFactory
 */
export default class Required extends ValidatorFactory {
  name = "required";

  validate(value, dataContext = {}) {
    const {
      errorMsg = {
        inline: "validation:rule.required.inline",
        summary: "validation:rule.required.summary",
      },
    } = this.config;

    if (!isEmpty(value)) {
      return [];
    }

    return [ValidationError.make({ errorMsg, dataContext })];
  }

  sanitise(value) {
    const coerce = (val) => {
      const s = stringifyInput(val, undefined);
      return s === undefined ? undefined : s.replace(/^\s+$/, "");
    };

    if (isStringable(value)) {
      return coerce(value);
    }

    // Coerce all elements to Strings.
    // This only supports one dimensional array, with stringable element.
    if (Array.isArray(value)) {
      return value.map(coerce);
    }

    // Coerce all elements to Strings.
    // This only supports a one dimensional object, with stringable elements.
    if (isPlainObject(value)) {
      return Object.fromEntries(
        Object.entries(value).map(([k, v]) => [k, coerce(v)]),
      );
    }

    return undefined;
  }
}