backtickString.ts

import {addError} from './utils.js';

import type {MutableImportsExports, OnParse} from './types';

/**
 * Adds error of parsing string literal started with backtick.
 */
export const onBacktickError: OnParse<MutableImportsExports, 1> = (
  importsExports,
  _source,
  {start, end},
) =>
  addError(importsExports, 'Cannot find end of string literal started with backtick', start, end);

/**
 * Parses string literal started with backtick.
 */
export const onBacktickParse: OnParse<MutableImportsExports, 2> = (
  importsExports,
  source,
  parsedToken,
) => {
  var depth = 0;
  var index = parsedToken.end;

  for (; index < source.length; index += 1) {
    const char = source[index];

    if (char === '$') {
      if (source[index + 1] === '{' && source[index - 1] !== '\\') {
        depth += 1;
        index += 1;
      }
    } else if (char === '}') {
      if (depth !== 0) {
        depth -= 1;
      }
    } else if (depth === 0 && char === '`' && source[index - 1] !== '\\') {
      return index + 1;
    }
  }

  return addError(
    importsExports,
    'Cannot find end of nested string literal started with backtick',
    parsedToken.start,
    source.length,
  );
};