Function getErrorSource

lib/internal/source_map/prepare_stack_trace.js:149–176

* Return a snippet of code from where the exception was originally thrown * above the stack trace. This called from GetErrorSource in node_errors.cc. * @param {import('internal/source_map/source_map').SourceMap} sourceMap - the source map to be used * @param {string} originalSourcePath - path or

(
  sourceMap,
  originalSourcePath,
  originalLine,
  originalColumn,
)

 * @returns {string | undefined} - the exact line in the source content or undefined if file not found
 */
function getErrorSource(
  sourceMap,
  originalSourcePath,
  originalLine,
  originalColumn,
) {
  const line = getSourceLine(sourceMap, originalSourcePath, originalLine);
  if (!line) {
    return;
  }
  const originalSourcePathNoScheme =
    StringPrototypeStartsWith(originalSourcePath, 'file://') ?
      fileURLToPath(originalSourcePath) : originalSourcePath;

  // Display ^ in appropriate position, regardless of whether tabs or
  // spaces are used:
  let prefix = '';
  for (const character of new SafeStringIterator(
    StringPrototypeSlice(line, 0, originalColumn + 1))) {
    prefix += character === '\t' ? '\t' :
      StringPrototypeRepeat(' ', getStringWidth(character));
  }
  prefix = StringPrototypeSlice(prefix, 0, -1); // The last character is '^'.

  const exceptionLine =
   `${originalSourcePathNoScheme}:${originalLine + 1}\n${line}\n${prefix}^\n`;
  return exceptionLine;
}

/**
 * Retrieve exact line in the original source code from the source map's `sources` list or disk.