···528528529529- Keys with `undefined` properties are checked. e.g. `{a: undefined, b: 2}` does not match `{b: 2}` when using `.toStrictEqual`.
530530- Array sparseness is checked. e.g. `[, 1]` does not match `[undefined, 1]` when using `.toStrictEqual`.
531531-- Object types are checked to be equal. e.g. A class instance with fields `a` and` b` will not equal a literal object with fields `a` and `b`.
531531+- Object types are checked to be equal. e.g. A class instance with fields `a` and `b` will not equal a literal object with fields `a` and `b`.
532532533533```ts
534534import { expect, test } from 'vitest'