Game testing
Unity Test Framework
By Unity Technologies
Unity's NUnit-based testing package for Edit Mode, Play Mode and target-platform player tests.
Check com.unity.test-framework and open Window > General > Test Runner to create a Test Assembly Folder. Add game-rule tests and a Play Mode smoke test for the main scene. Check the .asmdef platform settings for target-player tests because assemblies created through Test Runner default to Editor only. Tests help catch regressions, not establish game feel; review UnityTest limitations for your version.
Sources: https://docs.unity3d.com/Packages/com.unity.test-framework@1.4/manual/index.html · https://docs.unity3d.com/Packages/com.unity.test-framework@1.4/manual/workflow-create-test-assembly.html