# Suggest using `toStrictEqual()` (`prefer-strict-equal`) 💡 This rule is manually fixable by [editor suggestions](https://eslint.org/docs/developer-guide/working-with-rules#providing-suggestions). `toStrictEqual` not only checks that two objects contain the same data but also that they have the same structure. It is common to expect objects to not only have identical values but also to have identical keys. A stricter equality will catch cases where two objects do not have identical keys. ## Rule details This rule triggers a warning if `toEqual()` is used to assert equality. The following pattern is considered warning: ```js expect({ a: 'a', b: undefined }).toEqual({ a: 'a' }); // true ``` The following pattern is not warning: ```js expect({ a: 'a', b: undefined }).toStrictEqual({ a: 'a' }); // false ```