Allow customising memory limits for Cypress workers for lower memory CI instances.

Description

I would like to be able to reduce the amount of memory workers take when using the plugin. At the moment, when I run nx run myapp:e2e it prints Using 1 worker with 2048MB memory limit.

- Generating browser application bundles (phase: setup)...
[...]
** Angular Live Development Server is listening on localhost:4200, open your browser on http://localhost:4200/ **
✔ Compiled successfully.
[...]
====================================================================================================

  (Run Starting)

  ┌────────────────────────────────────────────────────────────────────────────────────────────────┐
  │ Cypress:    7.5.0                                                                              │
  │ Browser:    Electron 89 (headless)                                                             │
  │ Specs:      3 found (modules/login/login/login-logout-redirect.spec.ts, modules/login/login/lo │
  │             gin.spec.ts, modules/login/logout/logout.spec.ts)                                  │
  └────────────────────────────────────────────────────────────────────────────────────────────────┘


────────────────────────────────────────────────────────────────────────────────────────────────────
                                                                                                    
  Running:  modules/login/login/login-logout-redirect.spec.ts                               (1 of 3)
Starting type checking service...
Using 1 worker with 2048MB memory limit
Starting type checking service...
Using 1 worker with 2048MB memory limit

• I would like to make each worker take 1024MB instead of 2048

Motivation

That way we could have users run their Cypress CI processes on lower memory instances.

I am running a GitLab Runner with 1 GB of RAM configured with 1 GB of swap space (AWS T3 Micro).

Suggested Implementation

For that to work we would need to tap into ForkTsCheckerWebpackPlugin’s constructor in order to inject the memoryLimit option with Nx.

Here’s the relevant file: https://github.com/nrwl/nx/blob/12.5.7/packages/cypress/src/plugins/preprocessor.ts#L53

      new ForkTsCheckerWebpackPlugin({
        tsconfig: config.env.tsConfig,
        useTypescriptIncrementalApi: false,
        ...suggestingDesigningSomeConfigurationObjectThatCanGetExpandedHere // <------- Customisable object!
      }),

So that way I could pipe the memoryLimit there as:

suggestingDesigningSomeConfigurationObjectThatCanGetExpandedHere = { memoryLimit: 1024 }; // <----- Customisable object!

Alternate Implementations

Maybe we could only target that memoryLimit option, since more people that are running pipelines on budget could have end to end CI without running out of memory or crashing the instance.

[skydever]

I have some great news 😄 … nx version 12.6.0-beta.6 came out yesterday and I did the migration today. now version 6.2.1 of fork-ts-checker-webpack-plugin is used, and I was able to set the memory limit like I tried before (using cosmiconfig) at package.json:

  "fork-ts-checker": {
    "typescript": {
      "memoryLimit": 8000
    }
  }

I added a console.log at my local \node_modules\fork-ts-checker-webpack-plugin\lib\ForkTsCheckerWebpackPlugin.js to verify that the memoryLimit will be used, and I got the expected output - and now my tests passed, no out of memory error 🎉

To sum up - memoryLimit should be added to the cypress config of nx to avoid the temp. workaround using cosmiconfig that is possible with version 12.6.0-beta.6 of nx (but be aware, the option will be considered for each instance of ForkTsCheckerWebpackPlugin if you use this workaround) 👍

[barbados-clemens]

Hi there, have y’all tried updating to the latest version of cypress or something > 7, as the preprocessor plugin isn’t needed. This will be removed in nx v14 as well. Let me know if it’s still an issue. Thanks!