function validateFileExtensionList()

in cloudrun-malware-scanner/config.ts [243:266]

• 21 lines of code
• 7 McCabe index (conditional complexity)

function validateFileExtensionList(extensionList: unknown): string[] {
  if (extensionList == null) {
    return [];
  }

  if (!(extensionList instanceof Array)) {
    throw new Error('value must be an array of strings');
  }
  const normalizedExtensionList: string[] = [];

  for (let i = 0; i < extensionList.length; i++) {
    const ext = extensionList[i] as unknown;
    if (typeof ext !== 'string') {
      throw new Error(`value [${i}] must be a string`);
    }
    if (ext.length > 0 && ext[0] !== '.') {
      normalizedExtensionList.push('.' + ext.toLocaleLowerCase());
    } else {
      normalizedExtensionList.push(ext.toLocaleLowerCase());
    }
  }

  return normalizedExtensionList;
}