validateRequired abstract method

List<String> validateRequired(
  1. List<String> requiredKeys
)

Ensures that all requiredKeys exist in the environment.

Returns a list of missing keys (empty list means all are valid).

Example:

final missing = env.validateRequired(['APP_KEY', 'DB_HOST']);
if (missing.isNotEmpty) {
  throw Exception('Missing environment keys: ${missing.join(', ')}');
}

Implementation

List<String> validateRequired(List<String> requiredKeys);