Test suite
A group of related tests run and reported together: one describe block, one file, or your entire test command.
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What it is
A test suite is a bundle of related test cases that get run and reported together. The word stretches across three sizes: one describe block, one file, or the entire thing your CI kicks off. Context tells you which one somebody means.
Grouping earns its keep through shared setup. A suite can spin up a database once in beforeAll, reset a table in beforeEach, and tear it all down at the end, so individual cases stay short. Suites are also the unit runners split across machines when the whole thing gets too slow, which is why people talk about sharding a suite.
Gotcha: order dependence. The moment case three only passes because case two left a user in the database, you have a suite that works locally and explodes when someone runs it in parallel or in random order. Reset state between cases and check by running the suite shuffled on purpose.
Ask AI for it
Organize these tests into a Vitest suite for the cart module: a top level describe with nested describes per behavior area (adding items, removing items, totals). Put database setup in beforeAll and per-test state reset in beforeEach so no case depends on another. Keep nesting at two levels max, and make sure the suite passes when run with randomized order and in parallel.