In DevTools tests, if the REACT_VERSION specified, we know this is a regression test (testing older React Versions). Because a lot of tests test the DevTools front end and we don't want to run them in the regression test scenario, we decided to only run tests that have the // @reactVersion pragma defined.
Because if there are no tests specified, jest will fail, we also opt to use jest.skip to skip all the tests that we don't want to run for a specific React version istead.
This PR makes this change.
This PR:
Adds a transform-react-version-pragma that transforms // @reactVersion SEMVER_VERSION into _test_react_version(...) and _test_react_version_focus(...) that lets us only run a test if it satisfies the right react version.
Adds _test_react_version and _test_react_version_focus to the devtools setupEnv file
Add a devtools preprocessor file for devtools specific plugins
