ERROR [karma-server]: UnhandledRejection when updated to 5.0

[rinick]

my unit tests worked fine with 4.x, and it also worked fine with 5.0 beta-1
but when switching to 5.0 release or 5.0 beta-3, it always show this error after all the tests are passed.

HeadlessChrome 80.0.3987 (Windows 10.0.0): Executed 231 of 231 SUCCESS (9.106 secs / 8.064 secs)
13 03 2020 17:37:51.532:ERROR [karma-server]: UnhandledRejection

any idea how I can trouble shoot this?

[erikbarke]

Do you have an example repo?

[christophercr]

@erikbarke I have the exact same issue, and when adding an error handler as suggested in karma-runner/karma#3378 (comment) (@rinick perhaps you can also do that to trouble shoot your problem), I'm able to see the actual error:

TypeError: Cannot read property 'push' of undefined
    at _reporters.forEach (C:\projectPath\node_modules\karma\lib\reporters\multi.js:13:24)
    at Array.forEach (<anonymous>)
    at MultiReporter.addAdapter (C:\projectPath\node_modules\karma\lib\reporters\multi.js:11:21)
    at Server.<anonymous> (C:\projectPath\node_modules\karma\lib\middleware\runner.js:41:18)
    at Object.onceWrapper (events.js:286:20)
    at Server.emit (events.js:203:15)
    at Executor.schedule (C:\projectPath\node_modules\karma\lib\executor.js:30:20)
    at C:\projectPath\node_modules\karma\lib\middleware\runner.js:92:22
    at tryCatcher (C:\projectPath\node_modules\bluebird\js\release\util.js:16:23)
    at Promise._settlePromiseFromHandler (C:\projectPath\node_modules\bluebird\js\release\promise.js:547:31)
    at Promise._settlePromise (C:\projectPath\node_modules\bluebird\js\release\promise.js:604:18)
    at Promise._settlePromise0 (C:\projectPath\node_modules\bluebird\js\release\promise.js:649:10)
    at Promise._settlePromises (C:\projectPath\node_modules\bluebird\js\release\promise.js:729:18)
    at Promise._fulfill (C:\projectPath\node_modules\bluebird\js\release\promise.js:673:18)
    at Promise._resolveCallback (C:\projectPath\node_modules\bluebird\js\release\promise.js:466:57)
    at Promise._settlePromiseFromHandler (C:\projectPath\node_modules\bluebird\js\release\promise.js:559:17)

The code that fails is this line: https://github.com/karma-runner/karma/blob/a673aa8ad76f733565498f2aab13fcd720502be1/lib/reporters/multi.js#L11 because the karma-typescript reporter has no adapters property.

Another thing that I have different compared to your Angular demo is the version of karma-jasmine. That one uses: "^2.0.1 whereas in my app I use version "^3.1.0"... but I'm not sure whether this is part of the root cause of the issue.

[rinick]

my issue is resolved, thanks to @christophercr 's suggestion.

the issue is caused by lvoconly report

        "lcovonly": {
          "directory": "coverage",
          "subdirectory": "chrome",
          "filename": "karma"
        }

I guess it was a bug in previous version, even I ask for filename karma, previous version still generated another layer of karma subfolder, then put lcov result in it.

latest version actually fixed it, but it failed to write to that file, because a folder with same name already exists.

after deleting the folder the UnhandledRejection is gone

[erikbarke]

Thanks guys, I've been able to reproduce at least the error @rinick gets by creating a folder with the same name as the lcov file and using the lcovonly report:

infrastructure_error Error: EISDIR: illegal operation on a directory, open '/Users/erikbarke/Development/npm/monounity/karma-typescript/examples/angular2/coverage/chrome/karma'
    at Object.openSync (fs.js:457:3)
    at FileWriter.writeFile (/Users/erikbarke/Development/npm/monounity/karma-typescript/examples/angular2/node_modules/istanbul-lib-report/lib/file-writer.js:185:41)
    at LcovOnlyReport.onStart (/Users/erikbarke/Development/npm/monounity/karma-typescript/examples/angular2/node_modules/istanbul-reports/lib/lcovonly/index.js:17:45)
    at Visitor.value (/Users/erikbarke/Development/npm/monounity/karma-typescript/examples/angular2/node_modules/istanbul-lib-report/lib/tree.js:38:38)
    at ReportTree.visit (/Users/erikbarke/Development/npm/monounity/karma-typescript/examples/angular2/node_modules/istanbul-lib-report/lib/tree.js:126:17)
    at LcovOnlyReport.execute (/Users/erikbarke/Development/npm/monounity/karma-typescript/examples/angular2/node_modules/istanbul-lib-report/lib/report-base.js:12:44)
    at /Users/erikbarke/Development/npm/monounity/karma-typescript/examples/angular2/node_modules/karma-typescript/src/karma/reporter.ts:79:30
    at Array.forEach (<anonymous>)
    at Reporter.create.<anonymous> (/Users/erikbarke/Development/npm/monounity/karma-typescript/examples/angular2/node_modules/karma-typescript/src/karma/reporter.ts:59:49)
    at step (/Users/erikbarke/Development/npm/monounity/karma-typescript/examples/angular2/node_modules/karma-typescript/dist/karma/reporter.js:33:23)
    at Object.next (/Users/erikbarke/Development/npm/monounity/karma-typescript/examples/angular2/node_modules/karma-typescript/dist/karma/reporter.js:14:53)
    at fulfilled (/Users/erikbarke/Development/npm/monounity/karma-typescript/examples/angular2/node_modules/karma-typescript/dist/karma/reporter.js:5:58)
    at processTicksAndRejections (internal/process/task_queues.js:97:5) {
  errno: -21,
  syscall: 'open',
  code: 'EISDIR',
  path: '/Users/erikbarke/Development/npm/monounity/karma-typescript/examples/angular2/coverage/chrome/karma'
}

Since this was caused by a bug in an earlier beta version I'm not sure there's anything to fix here, the istanbul reporter is already throwing an error about an "illegal operation on a directory", and having a coverage reporter deleting sub directories is probably a bad thing 🤔

On the other hand, I haven't been able to reproduce your error, @christophercr, what are the steps, do you have an example repo?

[christophercr]

@erikbarke I did more troubleshooting and now I know why I get the error. It is because I run the tests via my IDE (IntelliJ - WebStorm) and for some reason, the execution reaches this line: https://github.com/karma-runner/karma/blob/a673aa8ad76f733565498f2aab13fcd720502be1/lib/reporters/multi.js#L11.

However, if I run the tests in a terminal, they work just fine as that line of code is never reached.

Do you think you could add an adapters property to the karma-typescript reporter so that running from an IDE is supported? In my case I find it really useful to run them via the IDE cause there I get more structured and colored output and also I can even go directly to the code of the failing tests by doing Ctrl+click.

You could define the adapters property the same way as the BaseReporter does in Karma: https://github.com/karma-runner/karma/blob/a673aa8ad76f733565498f2aab13fcd720502be1/lib/reporters/base.js#L9. What do you think?

[erikbarke]

@christophercr, yes, this is probably a good idea and it seems the best way to add these kinds of properties is by using the baseReporterDecorator that Karma provides.

[erikbarke]

@christophercr, does the fix in #368 work for you?

[christophercr]

Yes, that does the trick! Then it works like a charm on Webstorm!

Thanks for the fix 😉