ember-template-lint/lib/rules/no-whitespace-within-word.js

Linter for Ember or Handlebars templates.

import Rule from './_base.js';

const ERROR_MESSAGE = 'Excess whitespace in layout detected.';

const WHITESPACE_ENTITY_LIST = [
  ' ',
  ' ',
  ' ',
  ' ',
  ' ',
  ' ',
  ' ',
  ' ',
  ' ',
  ' ',
  ' ',
  ' ',
  ' ',
  ' ',
  ' ',
  ' ',
  ' ',
  ' ',
  ' ',
  ' ',
  ' ',
  ' ',
  '  ',
  '​',
  '​',
  '​',
  '​',
  '​',
  '​',
  '‌',
  '‌',
  '‍',
  '‍',
  '‎',
  '‎',
  '‏',
  '‏',
  ' ',
  ' ',
  '  ',
  '⁠',
  '⁠',
  '⁡',
  '⁡',
  '⁡',
  '⁢',
  '⁢',
  '⁢',
  '⁣',
  '⁣',
  '⁣',
];

const CHARACTER_REGEX = '[a-zA-Z]';

// The goal here is to catch alternating non-whitespace/whitespace
// characters, for example, in 'W e l c o m e'.
//
// So the final pattern boils down to this:
//
// (whitespace)(non-whitespace)(whitespace)(non-whitespace)(whitespace)
//
// Specifically using this "5 alternations" rule since any less than this
// will return false positives and any more than this should not be
// necessary in 99.99% of cases
export default class NoWhitespaceWithinWord extends Rule {
  constructor(...args) {
    super(...args);

    let whitespaceOrEntityRegex = `(?:\\s|${WHITESPACE_ENTITY_LIST.map(
      (entity) => `\\${entity}`
    ).join('|')})+`;
    let characterRegex = CHARACTER_REGEX;

    this.regex = new RegExp(
      `${whitespaceOrEntityRegex}${characterRegex}${whitespaceOrEntityRegex}${characterRegex}${whitespaceOrEntityRegex}`
    );
  }
  /**
   * @returns {import('./types.js').VisitorReturnType<NoWhitespaceWithinWord>}
   */
  visitor() {
    return {
      TextNode(node, path) {
        let parents = [...path.parents()];
        if (
          parents.some((parent) => parent.node.type === 'AttrNode') ||
          parents.some(
            (parent) => parent.node.type === 'ElementNode' && parent.node.tag === 'style'
          )
        ) {
          return;
        }
        let source = this.sourceForNode(node);

        if (this.regex.test(source)) {
          this.log({
            message: ERROR_MESSAGE,
            node,
            source,
          });
        }
      },
    };
  }
}