Test smells — the short list

For Part F. Read your own suite against these five and find two.

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Mystery guest

The test depends on something it does not show you — a file on disk, a seeded database, a fixture built somewhere else.

Tell: you cannot tell what the input is by reading the test. Fix: build the input in the test, or commit a small fixture next to it.

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Resource optimism

The test assumes an environment it did not create, and passes or vanishes depending on the machine.

Tell: if (file.is_open()) with no else. A skip on a data condition. A comment saying "assuming there are at least three ___ in the database". Fix: supply the resource, or move the test to a suite that is run separately and knows it needs one.

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General fixture

One setup shared by every test, most of which no single test uses.

Tell: a SetUp() that resets globals. That is not organising the tests — it is undoing the previous one. Fix: take what the test needs as a parameter. A fixture that would disappear if the design were better is telling you about the design.

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Eager test

One test function exercising several behaviours.

Tell: it is long, and when it fails you cannot tell which behaviour broke without reading it. Fix: the arrangement can stay shared. Split the acts.

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Assertion roulette

Several bare assertions with no message. It fails at line 42 and the report says: line 42.

Tell: a loop full of asserts, or a run of them on positional values. Fix: name the thing, or assert on a whole structure at once so the diff shows you everything that moved.

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And the one that is not on the list

A test that passes whatever the code does. assert(result != nullptr). EXPECT_GE(count, 0). if (results) { ... }.

It is not a smell. It is a test that does not exist, written in a way that takes up space in the report. If you find one of these, it counts for Part F and you should say so plainly.