utils.ts

import type { AttributeToken } from 'pug-lexer';
import type {
  PugEmptyAttributes,
  PugEmptyAttributesForceQuotes,
} from './types';

const EMPTY_VALUES: Set<string | boolean> = new Set([true, '""', "''"]);

/**
 * Formats the token's `val` if it's empty, based on the `pugEmptyAttributes` option.
 *
 * @param token The attribute token.
 * @param pugEmptyAttributes The option.
 * @param pugEmptyAttributesForceQuotes Array with string-patterns for attribute names that needs empty quotes.
 */
export function formatEmptyAttribute(
  token: AttributeToken,
  pugEmptyAttributes: PugEmptyAttributes,
  pugEmptyAttributesForceQuotes: PugEmptyAttributesForceQuotes,
): void {
  const { val, name } = token;

  const forceQuotesPatterns: RegExp[] = pugEmptyAttributesForceQuotes.map(
    (pattern) => new RegExp(pattern),
  );
  const isForced: boolean = forceQuotesPatterns.some((pattern) =>
    pattern.test(name),
  );
  if (isForced) {
    if (token.val === true) {
      token.val = '""';
    }
    return;
  }

  if (pugEmptyAttributes === 'as-is' || !EMPTY_VALUES.has(val)) {
    return;
  }

  switch (pugEmptyAttributes) {
    case 'all': {
      if (token.val === true) {
        token.val = '""';
      }
      break;
    }
    case 'none': {
      if (token.val === '""' || token.val === "''") {
        token.val = true;
      }
      break;
    }
  }
}