why react should usually be a prod dependency and not dev-dependency

Question

Sorry if I'm missing some obvious thing, but I can't seem to understand why react (or react-dom) should be a dependency and not dev-dependency on most projects.. Usually the src is written in es6 and stored in /src or /client for example, and when someone want to build the project for prod he will create /build or /dist where the finalize bundle.js will seat (using webpack and such). from there (at prod) it simply a web server which serve regular js (the bundle) and html file.

Do I miss somthing?

I dont understand why will I want react on the prod (unless going for SSR of course)..

Thank you very much!

Answer 1

dependencies are required to run, devDependencies only to develop, e.g.: unit tests, Coffeescript to Javascript transpilation, minification, ...

React is a dependency because it is included in the final build.

In case of a React App, all your JSX is converted to a syntax similar to React.createElement and hence you would require your App to have React during run time as well. Similary methods like setState and lifecyle functions are all executed during run-time.

As a matter of fact react is a library that has exposed some methods and APIs to access and manipulate DOM.

Consider this similar to jquery or express where you add it in the production build because they are being used during run time.

When creating a react app, things like babel, webpack etc which are only used to create a bundle would be dev-dependencies as once the packaged bundle is generated it need not be generated during run time of application