check method

@override void check(DcqRegistry registry)

Implementation

@override
void check(DcqRegistry registry) {
  registry.addIndexExpression((node) {
    final index = node.index;
    if (index is! BinaryExpression) return;
    if (index.operator.lexeme != '-') return;

    final right = index.rightOperand;
    if (right is! IntegerLiteral || right.value != 1) return;

    final left = index.leftOperand;

    String? propertyName;
    if (left is PrefixedIdentifier) {
      propertyName = left.identifier.name;
    } else if (left is PropertyAccess) {
      propertyName = left.propertyName.name;
    }
    if (propertyName != 'length') return;

    final target = node.target;
    if (target == null) return;

    final targetType = target.staticType;
    if (targetType is! InterfaceType || targetType.element.name != 'List') {
      return;
    }

    if (left is PrefixedIdentifier) {
      if (left.prefix.toSource() != target.toSource()) return;
    } else if (left is PropertyAccess) {
      final leftTarget = left.target;
      if (leftTarget == null) return;
      if (leftTarget.toSource() != target.toSource()) return;
    }

    reportAtNode(node);
  });
}