Use a more sophisticated template for end-to-end testing of Create React App

[gaearon]

We currently test the same template we generate by default, which is probably file, but we miss out on testing more advanced features. Ideally we should have a kitchensink template that uses all possible features (JSX, Flow, NODE_PATH, generators, async/await, class properties etc), and make sure that that template builds and passes tests.

If you’d like to work on it, please write in this issue so others don’t duplicate effort. The task would consist of:

1. Looking at tasks/e2e.sh and learning how we test CRA
2. Figuring out how to make it use a different template just for e2e test—not sure how I’d do that so suggestions welcome
3. Creating that kitchensink template

[gaearon]

Stretch goal: use Jest snapshot testing for build output!
(You can look at Jest repo to see how Jest tests its own output with snapshots.)

[wdhorton]

I'd like to take a crack at this

[gaearon]

Cool, let me know if you stumble onto something. It’s a pretty open-ended task and will require some experimentation.

[wdhorton]

@gaearon For getting the e2e test to use a kitchensink template, would it be ok to pass an additional flag to create-react-app (like --use-kitchensink, --e2e, or --ci), which it would pass to scripts/init.js, where the copying of template actually happens? I can't really think of another way to get init to use a different template.

[gaearon]

Let’s make it --from-template <path>. We might eventually allow remote URLs there as well 😛