feat(jest): restrict usage of toBeTruthy or toBeFalsy (!97) · Merge requests · GitLab.org / Frontend / eslint-plugin · GitLab

Laurent Deketelaere requested to merge ali_o_kan/eslint-plugin:374983-add-rule-to-restrict-usage-of-tobetruthy-or-tobefalsy into main Sep 26, 2022

Context

In frontend testing guide:

Avoid using toBeTruthy or toBeFalsy

Jest also provides following matchers: toBeTruthy and toBeFalsy. We should not use them because they make tests weaker and produce false-positive results.

For example, expect(someBoolean).toBeFalsy() passes when someBoolean === null, and when someBoolean === false.

What does this MR do and why?

Add rule to restrict usage of toBeFalsy and toBeTruthy in spec/frontend/.eslintrc.yml