angular/angular · error · Error

Invalid Locale: '${locale}' is not a valid locale.

Error message

Invalid Locale: '${locale}' is not a valid locale.

What it means

Error "Invalid Locale: '${locale}' is not a valid locale." thrown in angular/angular.

Source

Thrown at packages/localize/tools/src/translate/output_path.ts:31

 */
export interface OutputPathFn {
  (locale: string, relativePath: string): string;
}

/**
 * Create a function that will compute the absolute path to where a translated file should be
 * written.
 *
 * The special `{{LOCALE}}` marker will be replaced with the locale code of the current translation.
 * @param outputFolder An absolute path to the folder containing this set of translations.
 */
export function getOutputPathFn(fs: PathManipulation, outputFolder: AbsoluteFsPath): OutputPathFn {
  const [pre, post] = outputFolder.split('{{LOCALE}}');
  return post === undefined
    ? (_locale, relativePath) => fs.join(pre, relativePath)
    : (locale, relativePath) => {
        if (/[\/\\]|\.\./.test(locale)) {
          throw new Error(`Invalid Locale: '${locale}' is not a valid locale.`);
        }

        const outputPath = fs.join(pre + locale + post, relativePath);
        const resolvedOutputPath = fs.resolve(outputPath);
        const resolvedPre = fs.resolve(pre);

        if (!resolvedOutputPath.startsWith(resolvedPre)) {
          throw new Error(`Invalid Locale: '${locale}' would cause path traversal.`);
        }

        return outputPath;
      };
}

View on GitHub (pinned to 51cb07e980)

Solutions

1. Use a valid BCP 47 locale code, e.g. en-US, fr, de-DE.

When it happens

Trigger: Thrown at packages/localize/tools/src/translate/output_path.ts:31 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of angular/angular@51cb07e980 (2026-08-22). Data as JSON: /api/errors/8042e79f840b6589. Report an issue: GitHub.