.NET Test Design

xUnit fixtures, test doubles, async behavior, and deterministic inputs.

4 drillsPractice one at a timeOrdered pathConcept questionComparison question

Recommended start

xUnit Fixtures

Structures xUnit tests around per-test instances and shares only expensive infrastructure through deliberate class, collection, or assembly fixture lifetimes while preserving isolation and parallel safety.

Easy~5 minStep 1 of 4

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1xUnit FixturesRecommended startStructures xUnit tests around per-test instances and shares only expensive infrastructure through deliberate class, collection, or assembly fixture lifetimes while preserving isolation and parallel safety.Concept questionEasy~5 min.NETC#xUnitPractice 2Test DoublesCompares test doubles by purpose and explains when a real dependency provides a more trustworthy test.Comparison questionMedium~7 min.NETC#xUnitPractice 3Async Test DesignTests asynchronous completion, caller cancellation, owned timeouts, cleanup, and race-sensitive side effects deterministically with controlled dependencies and bounded diagnostics.Concept questionMedium~7 min.NETC#xUnitPractice 4Deterministic InputsControls nondeterministic inputs without weakening production behavior or hard-coding test-only branches.Concept questionMedium~7 min.NETC#xUnitPractice