vitest-chain

Chain Vitest hooks so each one passes typed context to the next. The same API as mocha-chain, for Vitest.

import { expect } from 'vitest';
import { beforeEach, describe } from 'vitest-chain';

describe('Counter', () => {
    const withCounter = beforeEach(() => ({ counter: new Counter() }));

    withCounter.test('starts at zero', ({ counter }) => {
        expect(counter.increment()).toBe(1);
    });
});

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Features

• Typed context: a hook's return value is passed to the hooks and tests chained to it, so test state is never T | undefined.
• Vitest's own context too: chained callbacks receive the chain's context first, then Vitest's usual arguments, like the test context.
• Just Vitest: every function calls Vitest's own, and native Vitest calls can be mixed in.
• Order checked: a hook that runs before one it's chained to fails with HookOrderError, rather than getting an incomplete context.

Why mocha-chain explains the problem both solve, and Chaining hooks how chains work. Both apply to vitest-chain, with beforeAll and afterAll for Mocha's before and after.

Compared to

Vitest's test context can be extended with typed fixtures (test.extend), which are set up per test, on demand. vitest-chain uses hooks instead, so the same code works across Mocha and Vitest, and once-per-suite setup (beforeAll) can pass context as well.