ForkTsCheckerWebpackPlugin Configuration

[MarZab]

Currently, ForkTsCheckerWebpackPlugin is enabled when TypeScript is enabled.

While building, the service is run for each build, breaking the build when enough endpoints are defined:

Starting type checking service...
Starting type checking service...
Starting type checking service...
(node:6910) MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 exit listeners added to [process]. Use emitter.setMaxListeners() to increase limit

I would suggest a configuration option to not run ForkTsCheckerWebpackPlugin on build or to somehow run it before building.

[jayair]

Oh that's interesting. Does this error out the build?

[MarZab]

Yes, but not before freezing up my computer :D

Up to 4-5 endpoints it works, it does take a long time.

[ashutoshkmr]

I am also facing the same issue

[jayair]

@MarZab @ashutoshkmr Can you create a simple repo that I can test with?

[MarZab]

The issue shows up with package.individually = true.

With trivial examples it takes a few more endpoints than with larger codebase for the it to come up.

https://github.com/MarZab/serverless-bundle-typescript-timeout

% npm run sls package

Serverless: Bundling with Webpack...
Starting type checking service...
Starting type checking service...
Starting type checking service...
Starting type checking service...
Starting type checking service...
Starting type checking service...
Starting type checking service...
Starting type checking service...
Starting type checking service...
Starting type checking service...
(node:71290) MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 exit listeners added to [process]. Use emitter.setMaxListeners() to increase limit
(Use `node --trace-warnings ...` to show where the warning was created)
^C

[jayair]

Thanks for the repo.

I looked into it. It seems like serverless-webpack has been trying to resolve this issue (serverless-heaven/serverless-webpack#299 (comment)) and they have a proposed fix (serverless-heaven/serverless-webpack#517) in their upcoming 5.4.0 release.

It serializes the compile process. I still see the Node warning about the memory leak. But the functions seem to get packaged.

I created a branch for you to test with:

$ npm install --save-dev AnomalyInnovations/serverless-bundle#issue-127-forktschecker

And enable the option in your serverless.yml using:

custom:
  bundle:
    serializedCompile: true

I don't think the solution is ideal. I'd prefer being able to set the concurrency instead. But give it a shot.

[MarZab]

I tried on my project, and it did complete while also showing the memory leak.

But it took a lot longer so I did some testing. I added an option to disable forktschecker here.

Config	Build Time	System Load
tsForkTsChecker: false serializedCompile: false	69.41s	10
tsForkTsChecker: true serializedCompile: true	375.33s	21
tsForkTsChecker: true serializedCompile: false	frooze	427
tsc --noEmit	20.25s	7

My solution for now is to not use serializedCompile and to disable tsForkTsChecker compile time.

[jayair]

Yeah the serializedCompile will take longer. This option isn't directly related to forktschecker but it's a problem that a lot of people that use the package.individually option have. From having a look at the serverless-webpack 5.4.0 release roadmap, it seems like an issue they are trying to tackle. I'm leaning towards waiting for them to take a crack at it.

Maybe for the time being hang on to your solution?

[Namstel]

We're also running into this issue, but so far the only issue we have is that it slows down deployment by a lot.

Deployment with tsForkTsChecker turned off is 19 seconds and deployment with it turned on is 49 seconds.

I'm looking forward to seeing @MarZab 's solution in serverless-bundle.

[jayair]

@Namstel So it's faster with ForkTsChecker turned off?

[Namstel]

@jayair Yes definitely.

[jayair]

We are hearing a ton of folks having memory related issues because of this plugin. Anybody want to take a crack at this and making ForkTsChecker an option instead?

[ashutoshkmr]

Hey @jayair
I've created a PR to make ForkTsChecker an option