Why Vitest does not typecheck with typescript?

[gal-yedidovich]

with vitest the following test passes without errors:

import { it } from 'vitest'
it('example', () => {
	const a: number = 'string value'; // this is an invalid syntax
});

I would expect it to behave like jest and fail, with the error like Type 'string' is not assignable to type 'number'.

Is there a configuration to enable compiler check on the syntax & types? I would like to prevent mistakes from passing unintentionally

[jsphstls]

It is currently possible for vitest to typecheck all test files. However, the current documentation does not describe how to directly achieve this. Even worse, the documentation fails to disambiguate the term "typecheck." The docs largely refer to typechecking in the context of a typecheck test where the test is performing typechecks instead of tests getting typechecked.

Until those issues are addressed, here's how to typecheck your tests with vitest.

1. Enable "typecheck" in the vitest config. See Enable --typecheck by default? #7773
2. Include at least one *test-d.ts file. See: Typecheck not performed if there are no test-d files #5868

[Mythli]

This is super confusing
No logically thinking programmer would guess this.