I forked the lib to add a small feature but realised that dependencies were out of date, some npm errors and small things were missing. I also noticed that the lib hasn't seen a proper update in a while so I took the opportunity to give it a refresh. There's a fair few changes but I'll try my best to document everything I've done, it's still 100% backwards compatible.

Project

• Added .lock files to gitignore as it does more harm than good when working with contributors.
• Added a few missing fields to the package.json such as license, engines, keywords, bugs etc.
• Made it clear in package.json that it is semantically-released.
• Updated all deps to the latest and removed any unnecessary ones.
• Simplified a lot of the projects configs and removed unnecessary ones.
• Moved away from kcd-scripts because it makes it harder for contributors and maintainers to understand what is actually happening under the hood. The build tools required are really simple anyway so I added them all such as linting with eslint, building with babel, testing with jest and that's about it.
• Added some pre-commit hooks to lint and test files + lint commit messages.
• Added the missing Changelog.md file.
• Updated travis to test node (8, 10, 12) and use yarn instead of npm to speed it up.
• Cleaned up the Readme.md file and fixed anything broken.
• Added myself as a contributor.

Code

• Switched from jest-dom to @testing-library/jest-dom and added to Jest setup.
• Added in automatic cleanups to be run in the jest afterEach block.
• Added in a dont-clean-up-after-each file to avoid automatic cleanups. There's also an option to pass in the argument process.env.STL_SKIP_AUTO_CLEANUP to prevent it as well.
• Both the features above are found in other testing-library projects as well. It saves a fair few lines of boilerplate code and time.
• Override @testing-library/dom fireEvents method and make it run async by flushing pending state changes with tick. I know you don't have too as a simple await works but it's better to have it in code and clear, ontop it helps with adding proper types to the project.
• Added unmount to render results as a convenience function to call component.$destroy().
• Added rerender to render results to rerender a fresh component on the target.
• The two changes above are mainly because the component should not be returned in the rendering results, it defeats the purpose of testing library and goes against the guiding principle. I left it for backwards compatibility but I think it should be removed in a major update. I can bring it up as an issue later.
• Moved and added a bunch more tests to ensure everything is working as intended.
• There was missing render options such as the optional container and testing library queries. This was preventing users from passing in queries to the getQueriesForElement function. This addresses issue Issue: custom queries option is disregarded when passed to render function #52.
• Added types (index.d.ts) to the project.

I think that's everything ... Sorry for the slightly large update, hopefully it all looks good!