Take React.js's "Add React to a Website" article[1] for example. The example of adding JSX to an existing website[2]... breaks! And you won't exactly know when

Take React.js's "Add React to a Website" article[1] for example. The example of adding JSX to an existing website[2]... breaks! And you won't exactly know when until it does and you have to delete your package-lock.json file. It should work the first time, but once you commit those package versions, running `npx babel [...]` may break depending on what is in your package-lock.json file, and when. Why? Because installing the dependencies they specify and running babel (implicitly at the latest version) does not have reproducible results. It's that simple. package-lock.json is specifically supposed to help with this, but in some cases, it just doesn't, and it's entirely possible, and common(!) to have two sets of package.json files produce differing package-lock.json files. They even have a warning below that can still occur even if you already have the dependencies specified above installed: > If you see an error message saying “You have mistakenly installed the babel package”, you might have missed the previous step. Perform it in the same folder, and then try again. [1]: https://reactjs.org/docs/add-react-to-a-website.html https://reactjs.org/docs/add-react-to-a-website.html [2]: https://reactjs.org/docs/add-react-to-a-website.html#add-jsx-to-a-project https://reactjs.org/docs/add-react-to-a-website.html#add-jsx...