hbs-parser.js

import * as eslintScope from 'eslint-scope';
import { parseTemplate, DocumentLines, buildGlimmerVisitorKeys } from 'ember-estree';

// Constant: Program + all Glimmer node types. Computed once at module load.
const hbsVisitorKeys = { Program: ['body'], ...buildGlimmerVisitorKeys() };

/**
 * implements https://eslint.org/docs/latest/extend/custom-parsers
 * for Handlebars (.hbs) template files.
 *
 * The entire file is treated as a Glimmer template.
 * All locals not defined in the template are assumed to be defined
 * (no no-undef errors for template identifiers).
 */

/**
 * @type {import('eslint').ParserModule}
 */
export const meta = {
  name: 'ember-eslint-parser/hbs',
  version: '*',
};

export function parseForESLint(code, options) {
  const filePath = (options && options.filePath) || '<hbs>';
  const codeLines = new DocumentLines(code);

  let templateNode;
  try {
    templateNode = parseTemplate(code);
  } catch (e) {
    const loc = e.location || (e.hash && e.hash.loc);
    if (loc && loc.start) {
      const err = Object.assign(new SyntaxError(e.message), {
        lineNumber: loc.start.line,
        column: loc.start.column,
        index: codeLines.positionToOffset(loc.start),
        fileName: filePath,
      });
      throw err;
    }
    throw e;
  }

  const program = {
    type: 'Program',
    body: [templateNode],
    tokens: templateNode.tokens,
    comments: templateNode.comments || [],
    range: [0, code.length],
    start: 0,
    end: code.length,
    loc: {
      start: { line: 1, column: 0 },
      end: codeLines.offsetToPosition(code.length),
    },
  };

  const visitorKeys = hbsVisitorKeys;

  const scopeManager = eslintScope.analyze(
    { type: 'Program', body: [], range: [0, code.length], loc: program.loc },
    { range: true }
  );

  return { ast: program, scopeManager, visitorKeys, services: {} };
}

export default { meta, parseForESLint };