prefer-equality-matcher.md 735 Bytes

Suggest using the built-in equality matchers (prefer-equality-matcher)

Jest has built-in matchers for expecting equality which allow for more readable tests and error messages if an expectation fails.

Rule details

This rule checks for strict equality checks (=== & !==) in tests that could be replaced with one of the following built-in equality matchers:

  • toBe
  • toEqual
  • toStrictEqual

Examples of incorrect code for this rule:

expect(x === 5).toBe(true);
expect(name === 'Carl').not.toEqual(true);
expect(myObj !== thatObj).toStrictEqual(true);

Examples of correct code for this rule:

expect(x).toBe(5);
expect(name).not.toEqual('Carl');
expect(myObj).toStrictEqual(thatObj);