GoogleTest
Google's open suite combines unit tests, parameters, death tests, and GoogleMock.
Why use it
GoogleTest works well for substantial native codebases needing stable fixtures, interface mocks, and cross-platform CI output.
Where it fits
Use testing, performance, accessibility, and diagnostic tools to remove problems players will notice.
What to check
Macro-heavy APIs and builds add weight; excessive mocking can hide real engine threading, assets, and platform behavior.