Dart Use Pattern Matching skill: what it does and how to install it

What it does. Guides Dart 3 refactoring with map, list, record and object patterns, switch expressions and statements, guards, and sealed classes. It covers JSON validation, polymorphic response parsing, path segments, records and exhaustive type handling, with analyser checks and runtime verification for map keys.

When to use it. For complex conditionals, structured data, API responses, collection destructuring and algebraic data types. It advises against patterns for simple boolean conditions, single-variable type promotion, basic filtering and gratuitous destructuring.