nullables-testing-style

What problem does it solve?

Use this skill when refactoring code or writing tests in the Nullables style. It guides you to choose between new, .create(), and .createNull(), introduces infrastructure wrappers at the environment boundary, adds behavior simulation and output tracking, and encourages narrow, sociable, example-driven, state-based tests without mocks or spies.

Core Features & Use Cases

• Clear construction rules: prefer new for the class under test and .createNull() for dependencies.
• Infrastructure wrappers at the environment boundary to isolate I/O and provide configurable responses.
• Behavior simulation to model external events without hitting real environments.
• Output tracking to verify observable changes instead of spying on internal calls.
• Example-driven, state-based tests that are easy to read and reason about.

Quick Start

Create a test using new for the class under test, wire dependencies with .createNull() for nulled environments, add a minimal infrastructure wrapper, and write a short state-based example.