svelte: Source map line numbers are wrong when using typescript

/*
https://stackoverflow.com/questions/57188027/refactor-aliased-imports-to-relative-paths

pnpm i -D jscodeshift @babel/core

# problem: jscodeshift cannot parse *.svelte files
npx jscodeshift --extensions=svelte --parser=svelte -t codemods/alias-to-relative-import.cjs src

# JS dryrun + print
npx jscodeshift -t codemods/alias-to-relative-import.cjs src -d -p

# JS
npx jscodeshift -t codemods/alias-to-relative-import.cjs src

# TS dryrun + print
npx jscodeshift --extensions=ts --parser=ts -t codemods/alias-to-relative-import.cjs src -d -p

# TS
npx jscodeshift --extensions=ts --parser=ts -t codemods/alias-to-relative-import.cjs src

*/

const path = require("path");

function replacePathAlias(currentFilePath, importPath, pathMap) {
  // if windows env, convert backslashes to "/" first
  currentFilePath = path.posix.join(...currentFilePath.split(path.sep));

  const regex = createRegex(pathMap);
  return importPath.replace(regex, replacer);

  function replacer(_, alias, rest) {
const mappedImportPath = pathMap[alias] + rest;

// use path.posix to also create foward slashes on windows environment
let mappedImportPathRelative = path.posix.relative(
  path.dirname(currentFilePath),
  mappedImportPath
);
// append "./" to make it a relative import path
if (!mappedImportPathRelative.startsWith("../")) {
  mappedImportPathRelative = `./${mappedImportPathRelative}`;
}

logReplace(currentFilePath, mappedImportPathRelative);

return mappedImportPathRelative;
  }
}

function createRegex(pathMap) {
  const mapKeysStr = Object.keys(pathMap).reduce((acc, cur) => `${acc}|${cur}`);
  const regexStr = `^(${mapKeysStr})(.*)$`;
  return new RegExp(regexStr, "g");
}

const log = true;
function logReplace(currentFilePath, mappedImportPathRelative) {
  if (log)
console.log(
  "current processed file:",
  currentFilePath,
  "; Mapped import path relative to current file:",
  mappedImportPathRelative
);
}

/**
 * Corresponds to tsconfig.json paths or webpack aliases
 * E.g. "@/app/store/AppStore" -> "./src/app/store/AppStore"
 */
const pathMapping = {
  //"@": "./src",
  //"foo": "bar",
  "$src": "./src",
};

module.exports = function transform(file, api) {
  const j = api.jscodeshift;
  const root = j(file.source);

  root.find(j.ImportDeclaration).forEach(replaceNodepathAliases);
  root.find(j.ExportAllDeclaration).forEach(replaceNodepathAliases);

  /**
   * Filter out normal module exports, like export function foo(){ ...}
   * Include export {a} from "mymodule" etc.
   */
  root
.find(j.ExportNamedDeclaration, (node) => node.source !== null)
.forEach(replaceNodepathAliases);

  return root.toSource();

  function replaceNodepathAliases(impExpDeclNodePath) {
impExpDeclNodePath.value.source.value = replacePathAlias(
  file.path,
  impExpDeclNodePath.value.source.value,
  pathMapping
);
  }
};