toStrictEqual()
(prefer-strict-equal
)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.
This rule triggers a warning if toEqual()
is used to assert equality.
The following pattern is considered warning:
expect({ a: 'a', b: undefined }).toEqual({ a: 'a' }); // true
The following pattern is not warning:
expect({ a: 'a', b: undefined }).toStrictEqual({ a: 'a' }); // false