Suggest using `toHaveLength()` (`prefer-to-have-length`)

In order to have a better failure message, toHaveLength() should be used upon asserting expectations on object's length property.

Rule details

This rule triggers a warning if toBe(), toEqual() or toStrictEqual() is used to assert object's length property.

expect(files.length).toBe(1);

This rule is enabled by default.

The following patterns are considered warnings:

expect(files.length).toBe(1);

expect(files.length).toEqual(1);

expect(files.length).toStrictEqual(1);

The following pattern is not warning:

expect(files).toHaveLength(1);