Maximum Nesting

Maximum Nesting Level this is the maximum level of nesting blocks / control structures that are present in a method (or function). Code with deep nesting level are often complex and tough to maintain.

Generally the blocks with if, else, else if, do, while, for, switch, catch, etc statements are the part of nested loops.

Config example

dart_code_metrics:
  ...
  metrics:
    ...
    maximum-nesting-level: 5
    ...

Example

void visitBlock(Block node) {
  final nestingNodesChain = <AstNode>[];

  AstNode astNode = node;
  do {
    if (astNode is Block &&
        (astNode?.parent is! BlockFunctionBody ||
            astNode?.parent?.parent is FunctionExpression ||
            astNode?.parent?.parent is ConstructorDeclaration)) {
      nestingNodesChain.add(astNode);
    }

    astNode = astNode.parent;
  } while (astNode.parent != _functionNode);

  if (nestingNodesChain.length > _deepestNestingNodesChain.length) {
    _deepestNestingNodesChain = nestingNodesChain;
  }

  super.visitBlock(node);
}

Maximum Nesting Level for the example function is 3.