Function readChangeMetadata

src/utils/change-metadata.ts:94–147

(
  changeDir: string,
  projectRoot?: string
)

 * @throws ChangeMetadataError if the file exists but is invalid
 */
export function readChangeMetadata(
  changeDir: string,
  projectRoot?: string
): ChangeMetadata | null {
  const metaPath = path.join(changeDir, METADATA_FILENAME);

  if (!fs.existsSync(metaPath)) {
    return null;
  }

  let content: string;
  try {
    content = fs.readFileSync(metaPath, 'utf-8');
  } catch (err) {
    const ioError = err instanceof Error ? err : new Error(String(err));
    throw new ChangeMetadataError(
      `Failed to read metadata: ${ioError.message}`,
      metaPath,
      ioError
    );
  }

  let parsed: unknown;
  try {
    parsed = yaml.parse(content);
  } catch (err) {
    const parseError = err instanceof Error ? err : new Error(String(err));
    throw new ChangeMetadataError(
      `Invalid YAML in metadata file: ${parseError.message}`,
      metaPath,
      parseError
    );
  }

  // Validate with Zod
  const parseResult = ChangeMetadataSchema.safeParse(parsed);
  if (!parseResult.success) {
    throw new ChangeMetadataError(
      `Invalid metadata: ${parseResult.error.message}`,
      metaPath
    );
  }

  // Validate that the schema exists
  const availableSchemas = listSchemas(projectRoot);
  if (!availableSchemas.includes(parseResult.data.schema)) {
    throw new ChangeMetadataError(
      `Unknown schema '${parseResult.data.schema}'. Available: ${availableSchemas.join(', ')}`,
      metaPath
    );
  }

  return parseResult.data;
}

export interface ResolveSchemaForChangeOptions {
  metadata?: ChangeMetadata | null;