Karma issue in Jenkins pipeline

[tamiarah]

Hi colleagues,

We are currently facing the following issue, when we run our pipeline, where we also have a unit test step for our Karma + Jasmine tests:

We have 4 spec files - 2 of them always run through, but when it should start execute the other 2 specs, we often face the above error. With the second or third pipeline run, it finally runs through. However, it impedes our development extremely.
Unfortunately, I couldn't find any solution, when I searched for this error. I cannot reproduce this locally, it occurs only on our pipeline.

karma.conf.js is:

const path = require('path');
const failOnFirstRequest = require('../helper/failOnFirstRequest');

module.exports = function (config) {
    const pathToProjectRoot = '../../../../../';

    config.set({
        basePath: pathToProjectRoot + 'app/mkv_classes/',
        browsers: ['ChromeHeadless'],
        browserDisconnectTimeout: 60000,
        browserDisconnectTolerance: 4,
        browserNoActivityTimeout: 60000,

        files: ['webapp/test/**/*.spec.js'],
        exclude: [],

        ui5: {
            mode: 'script',
            type: 'application',
            url: 'https://sapui5.hana.ondemand.com',
            config: {
                bindingSyntax: 'complex',
                debug: false,
                inspect: true,
                async: false,
                resourceRoots: {
                    'com/sap/utilities/c4u/edom/mkv/mkv_classes': './base/webapp',
                },
            },
        },

        frameworks: ['ui5', 'jasmine', 'browserify'],
        reporters: ['junit', 'coverage', 'mocha'],

        specReporter: {
            maxLogLines: 5, // limit number of lines logged per test
            suppressErrorSummary: true, // do not print error summary
            suppressFailed: false, // do not print information about failed tests
            suppressPassed: false, // do not print information about passed tests
            suppressSkipped: false, // do not print information about skipped tests
            showSpecTiming: false, // print the time elapsed for each spec
            failFast: true, // test would finish with error when a first fail occurs.
        },
        mochaReporter: {
            ignoreSkipped: true,
        },
        junitReporter: {
            outputDir: '',
            outputFile: path.resolve(
                __dirname,
                pathToProjectRoot,
                's4hana_pipeline/reports/frontend-unit/Test-jasmine.tests.xml'
            ),
            suite: 'MKV application',
        },

        coverageReporter: {
            // specify a common output directory
            dir: path.join(__dirname, pathToProjectRoot, 's4hana_pipeline/reports/coverage-reports/frontend-unit/'),
            reporters: [
                {type: 'html', subdir: '/report-html/ut'},
                {type: 'lcov', subdir: 'report-lcosv'},
                {type: 'cobertura', subdir: 'app/mkv_classes', file: 'cobertura.frontend.unit.xml'},
                {type: 'text-summary'},
            ],
        },

        preprocessors: {
            'webapp/!(test)/**/*.js': 'coverage',
            'webapp/*.js': 'coverage',
            'webapp/test/**/*.spec.js': ['browserify'],
        },

        middleware: ['failOnFirstRequest'],
        plugins: [
            'karma-chrome-launcher',
            'karma-ui5',
            'karma-jasmine',
            'karma-junit-reporter',
            'karma-mocha-reporter',
            'karma-coverage',
            'karma-browserify',
            {
                'middleware:failOnFirstRequest': [
                    'factory',
                    function () {
                        return (req, res, next) => {
                            failOnFirstRequest(
                                (errorMessage) => {
                                    console.error(errorMessage);
                                    console.error('Exiting Karma');
                                    process.exit(1);
                                },
                                req,
                                res,
                                next
                            );
                        };
                    },
                ],
            },
        ],

        port: 9876,
        colors: true,
        logLevel: config.LOG_INFO,
        autoWatch: false,
        singleRun: true,
    });
};

package.json is:

{
    "name": "mkv_classes-ui",
    "version": "0.1.0",
    "private": true,
    "license": "UNLICENSED",
    "description": "",
    "dependencies": {},
    "devDependencies": {
        "@ui5/cli": "2.2.6",
        "browserify": "16.5.1",
        "cpy-cli": "3.1.1",
        "cross-env": "6.0.3",
        "jasmine-ajax": "4.0.0",
        "jasmine-core": "3.5.0",
        "karma": "4.4.1",
        "karma-browserify": "7.0.0",
        "karma-chrome-launcher": "3.1.0",
        "karma-cli": "2.0.0",
        "karma-coverage": "2.0.2",
        "karma-jasmine": "3.1.0",
        "karma-junit-reporter": "2.0.1",
        "karma-mocha-reporter": "2.2.5",
        "karma-ui5": "2.2.0",
        "lodash": "4.17.19",
        "rimraf": "3.0.2",
        "watchify": "3.11.1"
    },
    "scripts": {
        "build": "rimraf dist && ui5 build preload --include-task=generateManifestBundle generateCachebusterInfo && cpy ./xs-app.json dist",
        "test:unit": "cross-env NODE_ENV=unit karma start --browsers ChromeHeadless ./webapp/test/unit/karma.config.js",
        "test:unit:debug": "cross-env NODE_ENV=unit karma start --browsers Chrome ./webapp/test/unit/karma.config.js debug",
        "ci-frontend-unit-test": "npm run test:unit"
    },
    "engines": {
        "node": "^10.0.0"
    }
}

I already tried to find out more with the Log-Level 'Debug', but this doesn't give more information. I could imagine it is a config or version problem, but I am not sure.
Furthermore, our pipeline currently has space problems, not sure, if this plays a role for the above error.
Do you have any idea, how this could be solved?

Thank you very much already!
Best regards,
Christina

[RandomByte]

Hi Christina!

Thank you for filing this detailed issue.

However, I'm afraid that with the given information we can't provide you with any support at this moment. The described issue doesn't ring a bell for us.

There can be many causes for the error shown in the screenshot and it's quite possible that these are not directly related to karma-ui5. The fact that it only breaks infrequently might indicate an issue with your test setup or infrastructure and not with the configuration.