support bundle files without "index" in the name

[Traviskn]

We have a project where we have more entry-points in addition to the index.js, but these other entry-point files don't have index in their name. (If you're curious about the use-case for this, it's because we are using react-native-threads.

This PR is a different strategy for finding the dev server origin without looking specifically for index. I'm very open to feedback on this approach or if anyone has a better idea for going about it.

[zamotany]

With this approach, DEV_SERVER_ORIGIN is missing a protocol.

Also, do you use HMR in project??

[Traviskn]

Oh you're right this is incomplete, I totally left out the protocol!

I was running into red screen errors, failing on this line of the polyfillEnvironment file, even though I hadn't turned on HMR. If there's a way to somehow opt out of this file getting run when I don't need HMR that would be a fine workaround for our project.

[thymikee]

@Traviskn don't forget to rebase before you start working on that, we recently added a fix to this part of the codebase

[zamotany]

You can move
https://github.com/joltup/haul/blob/2b7eb739cbc7d39efdc12a263a100413d350f5e4/src/utils/polyfillEnvironment.js#L39-L52

into src/hot/client/index.js but then it might break HMR on physical iOS devises.

[satya164]

Can you rebase this against master?

[Traviskn]

Yes I'll rebase on master

[Traviskn]

While rebasing I noticed that the latest changes to the polyfillEnvironment.js actually do stop errors from being thrown, so my change isn't strictly necessary unless someone needs HMR in a bundle without index in the name.