use worker-rpc library for inter-process communication

[phryneas]

Over in #231, you suggested

I wonder if there's a way to tweak the checker to expose the checker purely for the purposes of testing... That could be potentially useful - it wouldn't need to be something we exposed always; we could have a "test" mode or something... Ideas!

To do that I need a way to do some inter-process communication that does not interfere with the given inter-process communication.

This PR adds worker-rpc so we can send different types of messages between the processes. Also, as it has a nice interface around promises, it acutally makes some existing code more readable.

As it did not want this to be swept under the rug by the myriad of other commits in #231, I created a separate PR for this so you can review it (I will continue using this in #231 as well, though)

[piotr-oles]

Thank you for your work! I like the RPC approach - it's a good direction to clean-up the codebase :)

[phryneas]

Okay, everything should be addressed - could you take a second look? :)

[johnnyreilly]

Looks really interesting!

My one reservation is that worker-rpc doesn't seem to be an actively maintained project and no-one is actively using it. (40 downloads a week on npm) This makes me hesitant to create a dependency on it.

However, it turns out worker-rpc is a pretty simple codebase; it pretty much amounts to this file: https://github.com/DirtyHairy/worker-rpc?files=1

I wonder, given it's already written in TypeScript and released under MIT if we couldn't just use that module in the fork-ts-checker-webpack-plugin codebase directly? I'd be happy to have a comment in the codebase that reflects that. And I'd be happy (if @DirtyHairy would like it) to have them listed as a contributor.

[phryneas]

Oh, I should have added that info: @DirtyHairy is actually a colleague of mine - as far as I know it's not maintained because it does what it needs to and there were no changes requested or required in the last few years.

We are actively using it in some customer projects and as far as I know he is using it heavily for web worker communication in his atari emulator ( https://github.com/6502ts/6502.ts ), so from my point of view I'd say it is quite mature.

As for the failing tests - I'll take a look at that tomorrow in the evening. Guess there were still tests using WorkResult.ts, even though the code did not reference it - and as I had a compiled version still sitting in the lib folder, my local tests did not fail.

[DirtyHairy]

What @phryneas says: both worker-rpc and microevent.ts (on which it depends) are maintained; they just haven't required much maintenance since I published them 😏 Both are heavily used in 6502.ts and are covered with tests. I trust them enough to use them in customer projects.

[phryneas]

Okay, there was actually a test for WorkResult, which was made obsolete by this PR. Now tests are actually running.

Tests are now failing for webpack 2 and 3, I'm on that.

[phryneas]

This test suite is great :) I had missed to migrate one RPC call - now everything should be good :)

[johnnyreilly]

Great! Question: does https://www.npmjs.com/package/@phryneas/experimental-fork-ts-checker-webpack-plugin use worker-rpc?

[phryneas]

Yes, but the version before the fix of yesterday, so the current build will not work on webpack 2/3.
I can merge it over and create a new build this evening.

[johnnyreilly]

That'd be awesome - thanks so much! I'm going to switch over my build at work to use this and see how it goes.

I'm very much a believer in dogfooding 😉

[johnnyreilly]

It would be great to get a release out with this in. @piotr-oles do you want to make that happen?

Given the experimental version has issues it would be good to ensure that the worker-rpc tweaks themselves are stable. I'm pretty optimistic, so let's ship!

[piotr-oles]

Yes, please release if you want to :)

[johnnyreilly]

Is there a way to do it without raising another PR to update the package.json... I'm guessing not?

[piotr-oles]

I will create PR with semantic-release integration to make releasing and versioning fully automatic :)

[johnnyreilly]

Nice! 😊❤️

Should I push out v1.0.3 in the meantime or would you rather I leave that so you can test your new mechanism?

[piotr-oles]

Please release v1.0.3 - I don't want to block you. I will release RC versions on beta channel to test it.

[johnnyreilly]

Should be out shortly https://github.com/Realytics/fork-ts-checker-webpack-plugin/releases/tag/v1.0.3

cc @phryneas