loadFromFile method

@override void loadFromFile(String path)

Loads environment variables from a file.

Supports standard .env file format with the following features:

• Comments (lines starting with #)
• Export statements (export KEY=value)
• Quoted values (single and double quotes)
• Variable substitution ($VAR or ${VAR})
• Escaped characters

If the file doesn't exist, this method returns silently.

env.loadFromFile('.env.local');
env.loadFromFile('config/production.env');

Implementation

@override
void loadFromFile(String path) {
  final file = File(path);
  if (!file.existsSync()) {
    return;
  }

  _loadedFiles.add(path);

  for (final line in file.readAsLinesSync()) {
    final trimmedLine = line.trim();

    // Skip empty lines and comments
    if (trimmedLine.isEmpty || trimmedLine.startsWith('#')) {
      continue;
    }

    // Handle export statements
    if (trimmedLine.startsWith('export ')) {
      final exportLine = trimmedLine.substring(7).trim();
      _parseEnvLine(exportLine);
      continue;
    }

    _parseEnvLine(trimmedLine);
  }
}