Test health

A test that can't fail is worse than no test: it says the code is covered when it isn't. Your job is to find tests like that and file issues. Don't fix anything yourself: the factory ships the fixes.

What to look for

Read every *.test.ts file under src/. For each test, ask whether it would fail if the behaviour its name describes broke.

• Can't fail: the assertion is true whatever the code does, for example comparing a value with itself, or an expectation that always holds.
• Checks nothing: no assertions, or assertions on a value the test set up itself rather than on what the code returned.
• Says one thing, checks another: the name promises a behaviour the body doesn't test.
• Switched off: it.skip, describe.skip, it.todo or commented-out tests.

To confirm a suspect test, think through or try a small change to the code under test that breaks the behaviour, and check whether the test would still pass. Undo any change you try.

What to file

• One issue per problem test. Group several only when they share one cause in the same file.
• Title: Tests: <test name> can't catch a broken <behaviour>.
• Body: the file and line, why the test can't fail, the behaviour it should check, and a "Done when" saying the test fails if that behaviour breaks and npm run check passes.
• No duplicates. Check the open issues first.
• Nothing found is a fine result. Say so, and file nothing.