Unit tests and regression tests can both find defects, but they answer different questions. Load tests examine behavior under an expected workload; stress tests push beyond normal limits. Before reading pass and fail counts, identify what the test was designed to verify.
Key terms
Unit tests examine small units; regression tests check whether a change broke existing behavior. Load and stress tests examine different workload conditions.
| Term | Meaning |
|---|---|
Test case | A specified set of inputs, conditions, steps, and expected results used to check a behavior. Recorded cases also show what was covered and provide evidence of execution. |
unit test | A test of a small unit of software, such as a function or module, generally in isolation from unrelated components. |
white-box testing | Testing informed by the implementation's internal structure or paths. It does not by itself guarantee that every possible path is tested. |
black box testing | Testing observable behavior against requirements without relying on knowledge of internal implementation. |
Terms to distinguish
| Term | Meaning |
|---|---|
Pareto principle | The heuristic that a small share of causes may account for a large share of effects, often illustrated as 80/20. The exact ratio is not a law or a guaranteed defect distribution. |
Pesticide Paradox | The observation that running the same tests repeatedly may stop revealing new defects; vary and update tests as the software changes. |
walkthrough | A review in which the author guides other people through a work product to gather feedback and find issues. |
inspection | A structured review of a work product against defined criteria to find defects and improvements. |
Terms in code
| Term | Meaning |
|---|---|
regression test | A test that checks whether previously working behavior still works after a change or fix. |
test oracle | A source or method for deciding the expected result, or whether an observed result is correct. |
Load testing | Measures application behavior under an intended or representative workload over a defined period. |
Stress testing | Examines behavior when workload or another resource demand exceeds normal limits. |
Reading a technical document
Both load and stress testing apply demand, but one checks expected operating conditions while the other probes limits and failure behavior.
First find the test target, then the conditions and expected result. A successful unit test cannot establish that an entire service handles production traffic; a stress test needs a clear definition of what failure and recovery should look like.
Key takeaways
Ask what is tested, under which conditions, and against which expected result.
- Test case — Describes inputs, conditions, and expected behavior, and records the scope tested.
- walkthrough — An author-guided review of a work product.
- Stress testing — Probes behavior beyond normal workload or resource limits.
