This tests the property "if we remove an element from a list, the element is no longer in the list". The remove function we use however only actually removes the first instance of the element, so this fails whenever the list contains a duplicate and we try to remove one of those elements.
This example is interesting for a couple of reasons:
- It's a nice easy to explain example of property-based testing.
- Shrinking duplicates simultaneously is something that most property-based testing libraries can't do.
The expected smallest falsified sample is ([0, 0], 0).
| Library | Code | Report |
|---|---|---|
| Americium | DeletionTest.java | deletion.md |
| jqwik | DeletionProperties.java | deletion.md |
| fast-check | deletion.js | deletion.md |
| CsCheck | ShrinkingChallengeTests.cs | deletion.md |
| elm-test | Deletion.elm | deletion.md |