Browser disconnect during coverage

[arobinson]

We are experiencing disconnects of the browser almost 100% of the time with karma-coverage. It used to happen on occasion, but now it happens consistently. On a MacBookPro it rarely happens, but we do see the CPU hit hard and memory usage go up to large numbers (node process at 6GB and browser at 2.5-3 GB). On an 8GB AWS Linux EC2, the browser disconnects. In the past, before I disabled our code's console logging, it was not uncommon to core dump the chromium process during unit tests.

This is the error message we get:

00:53:47.061  Chrome Headless 112.0.5614.0 (Linux x86_64) ERROR
00:53:47.061    Disconnected reconnect failed before timeout of 2000ms (ping timeout)
00:53:47.061  Chrome Headless 112.0.5614.0 (Linux x86_64) ERROR
00:53:47.061    Disconnected reconnect failed before timeout of 2000ms (ping timeout)
00:53:47.061  Chrome Headless 112.0.5614.0 (Linux x86_64) ERROR
00:53:47.061    Disconnected reconnect failed before timeout of 2000ms (ping timeout)

Turning coverage off fixes the issue, but as a result we have no code coverage.

We are using karma-coverage version 2.2.1

Angular environment:

Angular CLI: 16.2.4
Node: 18.17.0
Package Manager: pnpm 8.6.12
OS: darwin arm64

Angular: undefined
...

Package                      Version
------------------------------------------------------
@angular-devkit/architect    0.1602.4
@angular-devkit/core         16.2.4
@angular-devkit/schematics   16.2.4
@schematics/angular          16.2.4

Karma coverage settings:

{
    plugins: [karmaCoverage],
    coverageReporter: {
      type: 'html',
      dir: coverageDirectory,
      subdir: '.',
      includeAllSources: true,
      reporters: [
        { type: 'html', subdir: '.' },
        { type: 'lcov', projectRoot: projectDirectory }
      ] as any
    }
  }

Other karma settings:

{
    browserDisconnectTimeout: 25_000,
    browserDisconnectTolerance: 0,
    browserNoActivityTimeout: 600_000,
    captureTimeout: 600_000,
    browserSocketTimeout: 19_200_000,
    pingTimeout: 19_200_000,
    processKillTimeout: 10_000
  }

I've tried also disabling includeAllSources. I've also played around with trying to exclude files to cover in the angular JSON using codeCoverageExclude but no help

We have a large project, with ~550 spec files and 16,000 unit tests. Our source code, including the tests, is approximately 1 million lines of typescript code.

We are looking to potentially break up our code into Angular libraries in the future, but I'm looking for a more short-term work-around for this issue

Any assistance would be appreciated.

[KevinPartingtonTR]

I'm running into similar issues with our large project. At this point, the only option I think we have in my project is splitting code into Angular libraries, so we're doing that right now.

It's very unfortunate that this issue hasn't even had a reply from anyone in the karma-coverage community, but I guess it's to be expected when Karma itself is deprecated.

EDIT: Oh, forgot to mention that one "option" might be to disable source maps. This results in tests/coverage completing for us-- however, the coverage report is inaccurate and trends low. So, not a great option at all. But it could be useful in the short term if your actual code coverage is moderately higher than any thresholds you have set.