Allow already injected to be reset

[milesj]

to: @lencioni

We have some logic in our app that deletes injected CSS rules (mostly global styles). This works great.

However, once the styles are regenerated and attempt to inject again, they will not as Aphrodite blocks the injection because the previous key is set to alreadyInjected. https://github.com/Khan/aphrodite/blob/master/src/inject.js#L159

This PR adds a minor function called resetInjected to clear this cache. I also went ahead and exported reset since it may also be useful.

Not sure how to test this since all the logic is abstracted away.

[milesj]

@lencioni You have any feedback?

[lencioni]

Can someone from Khan please take a look as well?

[lencioni]

Can you please add a test?

[milesj]

@lencioni Not sure how to test this since alreadyInjected isn't exported, and exporting a let var doesn't seem like a good idea.

[lencioni]

@milesj how about an integration test that uses aphrodite to inject styles into the DOM, and then removes the styles, and then calls your new function, and then uses aphrodite to inject that style into the DOM again and verify that all worked?

[milesj]

@lencioni Added.

[lencioni]

Thanks for the test! Do you know why CI is failing on Node 6?

[milesj]

@lencioni I do not but will look into it.

I'd also suggest just dropping v6 since it's LTS is over.

[milesj]

@lencioni @kevinbarabash Any update here?

[lencioni]

Thanks for the ping! I'd really like for someone from Khan to review this. @kevinbarabash can you help with that?

[milesj]

Bump? @kevinbarabash