- Move from Mocha to Jest for JS testing (Jest seems to have better support for
'watching' tests and a more active community these days).
- Codemod existing tests to Jest syntax (using https://github.com/skovhus/jest-codemods)
- Fix some errors in tests that were previously hidden.
- Update Babel.
* Updates eslint packages
* Expected parentheses around arrow function argument having a body with curly braces
* Prop type `object` is forbidden
* Visible, non-interactive elements should not have mouse or keyboard event listeners
* Prop type is defined but not used
* Unexpected use of file extension "jsx"
* Expected 'this' to be used by class method
* HTML entities must be escaped
* Prevent default behavior on more options button click
