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jest/prefer-to-contain Style

What it does

In order to have a better failure message, toContain() should be used upon asserting expectations on an array containing an object.

Why is this bad?

TThis rule triggers a warning if toBe(), toEqual() or toStrictEqual() is used to assert object inclusion in an array

Example

javascript
// valid
expect(a).toContain(b);
expect(a).not.toContain(b);

// invalid
expect(a.includes(b)).toBe(true);
expect(a.includes(b)).not.toBe(true);
expect(a.includes(b)).toBe(false);
expect(a.includes(b)).toEqual(true);
expect(a.includes(b)).toStrictEqual(true);

References

Released under the MIT License.