Function maybeLoadFromExternalFile

src/util/file.ts:75–231

(
  filePath: string | object | Function | undefined | null,
  context?: 'assertion' | 'general' | 'vars',
)

 * @throws {Error} If the specified file does not exist.
 */
export function maybeLoadFromExternalFile(
  filePath: string | object | Function | undefined | null,
  context?: 'assertion' | 'general' | 'vars',
) {
  if (Array.isArray(filePath)) {
    return filePath.map((path) => {
      const content: any = maybeLoadFromExternalFile(path, context);
      return content;
    });
  }

  if (typeof filePath !== 'string') {
    return filePath;
  }
  if (!filePath.startsWith('file://')) {
    return filePath;
  }

  // Render the file path using Nunjucks
  const renderedFilePath = getNunjucksEngineForFilePath().renderString(filePath, {});

  // Parse the file URL to extract file path and function name using existing utility
  // This handles colon splitting correctly, including Windows drive letters (C:\path)
  const { filePath: cleanPath, functionName } = parseFileUrl(renderedFilePath);

  // In assertion contexts, always preserve Python/JS file references
  // This prevents premature dereferencing of assertion files that should be
  // handled by the assertion system, not the generic config loader
  if (context === 'assertion' && (cleanPath.endsWith('.py') || isJavascriptFile(cleanPath))) {
    logger.debug(`Preserving Python/JS file reference in assertion context: ${renderedFilePath}`);
    return renderedFilePath;
  }

  // In vars contexts, preserve all file:// references for test case expansion
  // This prevents premature file loading - JS/Python files should be executed at runtime
  // by renderPrompt in evaluatorHelpers.ts, and glob patterns should be expanded by
  // generateVarCombinations in evaluator.ts
  if (context === 'vars') {
    logger.debug(`Preserving file reference in vars context: ${renderedFilePath}`);
    return renderedFilePath;
  }

  // For Python/JS files with function names, return the original string unchanged
  // to allow the assertion system to handle function loading at execution time.
  // This prevents premature file existence checks that would fail for function references.
  if (functionName && (cleanPath.endsWith('.py') || isJavascriptFile(cleanPath))) {
    return renderedFilePath;
  }

  // For non-Python/JS files, use the original path (ignore potential function name)
  const pathToUse =
    functionName && !(cleanPath.endsWith('.py') || isJavascriptFile(cleanPath))
      ? renderedFilePath.slice('file://'.length) // Use original path for non-script files
      : cleanPath;

  const resolvedPath = path.resolve(cliState.basePath || '', pathToUse);

  // Check if the path contains glob patterns