pug-comment-preserve-spaces.ts

import type { ChoiceSupportOption } from 'prettier';
import { CATEGORY_PUG } from './constants';

/** Pug comment preserve spaces option. */
export const PUG_COMMENT_PRESERVE_SPACES_OPTION: ChoiceSupportOption<PugCommentPreserveSpaces> =
  {
    // since: '1.6.0',
    category: CATEGORY_PUG,
    type: 'choice',
    default: 'keep-all',
    description: 'Change behavior of spaces within comments.',
    choices: [
      {
        value: 'keep-all',
        description:
          'Keep all spaces within comments. Example: `//    this  is   a   comment`',
      },
      {
        value: 'keep-leading',
        description:
          'Keep leading spaces within comments. Example: `//    this is a comment`',
      },
      {
        value: 'trim-all',
        description:
          'Trim all spaces within comments. Example: `// this is a comment`',
      },
    ],
  };

/** Pug Comment preserve spaces. */
export type PugCommentPreserveSpaces = 'keep-all' | 'keep-leading' | 'trim-all';

/**
 * Format comment with the given settings.
 *
 * @param input The comment.
 * @param pugCommentPreserveSpaces How to preserve spaces in the comment.
 * @param pipeless Whether it's a pipeless comment ot not. Default: `false`.
 * @returns The formatted comment.
 */
export function formatPugCommentPreserveSpaces(
  input: string,
  pugCommentPreserveSpaces: PugCommentPreserveSpaces,
  pipeless: boolean = false,
): string {
  switch (pugCommentPreserveSpaces) {
    case 'keep-leading': {
      let result: string = '';
      let firstNonSpace: number = 0;
      for (
        firstNonSpace;
        firstNonSpace < input.length && input[firstNonSpace] === ' ';
        firstNonSpace++
      ) {
        result += ' ';
      }
      result += input.slice(firstNonSpace).trim().replaceAll(/\s\s+/g, ' ');
      return result;
    }
    case 'trim-all': {
      let result: string = input.trim();
      result = result.replaceAll(/\s\s+/g, ' ');
      if (!pipeless && input[0] === ' ') {
        result = ` ${result}`;
      }
      return result;
    }
    case 'keep-all':
    default: {
      // Don't touch comment
      return input;
    }
  }
}