function migrateContents(contents) {
  let newContents = contents;
  for (const migrationData of database) {
    newContents = fixImport(newContents, migrationData);
  }
  return newContents;
}
Migrates the contents of a particular file, renaming references and
adding/updating imports.
@param {string} contents The string contents of the file to migrate.
@returns {string} The migrated contents of the file.