Unit Testing

Conventions

• Co-locate tests: foo.test.ts next to foo.ts
• Always wrap in describe named after the unit under test
• Use test, not it
• Test behavior through public interfaces, not implementation details
• Good tests survive refactors — if the public API doesn't change, tests shouldn't break

describe("createCart", () => {
  test("calculates total for multiple items", () => { ... });
  test("returns empty items for new cart", () => { ... });
});

Vitest API