encapsulated-method-object

1. When to use this skill

Use this skill when you encounter a Dart function or class method suffering from the "Bloated Closure" or "Deeply Nested Scope" smell. Specifically, target functions matching these criteria:

• Deeply Nested Scope: The function declares one or more inner/local functions to perform sub-tasks.
• Shared Local State: Those local functions rely heavily on capturing variables declared in the outer function's scope (closure capturing).
• High Complexity: The top-level function contains many local variables, is difficult to unit test in isolation, or has high cyclomatic complexity.
• Parameter Bloat: If you try to extract local functions to separate methods, you must pass large amounts of state as parameters.

Core Concepts

This is a Dart-specific variation of Martin Fowler's classic refactoring "Replace Method with Method Object". It consists of three primary elements: