Using Karma + Jasmine, what is the best way to run only one test at a time? - karma-runner

Question

Is the best way to do that, simply to use the .only flag?
However, if I used describe.only(, I get
Uncaught TypeError: describe.only is not a function
So how can I run/debug only one test at a time?
Here is my karma.conf.js file:
const path = require('path');
module.exports = function (config) {
config.set({
// base path that will be used to resolve all patterns (eg. files, exclude)
basePath: '',
// frameworks to use
// available frameworks: https://npmjs.org/browse/keyword/karma-adapter
frameworks: ['jasmine'],
// list of files / patterns to load in the browser
files: [
'./node_modules/angular/angular.js',
'./node_modules/angular-ui-router/release/angular-ui-router.js',
'./node_modules/angular-mocks/angular-mocks.js',
// './public/pages/admin/specs/abc.js'
'./public/dist/app-production.js',
// './public/**/*.spec.js'
],
// list of files to exclude
exclude: [],
// preprocess matching files before serving them to the browser
// available preprocessors: https://npmjs.org/browse/keyword/karma-preprocessor
preprocessors: {},
// test results reporter to use
// possible values: 'dots', 'progress'
// available reporters: https://npmjs.org/browse/keyword/karma-reporter
reporters: ['spec', 'junit', /*progress*/],
junitReporter: {
outputDir: 'karma-results',
outputFile: 'karma-results.xml'
},
// web server port
port: 9876,
// enable / disable colors in the output (reporters and logs)
colors: true,
// level of logging
// possible values: config.LOG_DISABLE || config.LOG_ERROR || config.LOG_WARN || config.LOG_INFO || config.LOG_DEBUG
logLevel: config['LOG_WARN'],
// enable / disable watching file and executing tests whenever any file changes
autoWatch: false,
// start these browsers
// available browser launchers: https://npmjs.org/browse/keyword/karma-launcher
browsers: [/*Chrome*/ 'PhantomJS'],
// process.env.USER === dftjenkins
plugins: [
'karma-phantomjs-launcher',
'karma-chrome-launcher',
'karma-jasmine',
'karma-junit-reporter',
'karma-spec-reporter'
],
// Continuous Integration mode
// if true, Karma captures browsers, runs the tests and exits
singleRun: true,
// Concurrency level
// how many browser should be started simultaneous
concurrency: 5
})
};

Answer 1

The solution I have for the moment works quite well, all I do is change one line of our karma.conf.js file, like so:
before:
files: [
'./node_modules/angular/angular.js',
'./node_modules/angular-ui-router/release/angular-ui-router.js',
'./node_modules/angular-mocks/angular-mocks.js',
'./public/dist/app-production.js',
'./public/**/*.spec.js'
],
after:
files: [
'./node_modules/angular/angular.js',
'./node_modules/angular-ui-router/release/angular-ui-router.js',
'./node_modules/angular-mocks/angular-mocks.js',
'./public/dist/app-production.js',
process.env.KARMA_TEST_PATH || './public/**/*.spec.js'
],
now your just run karma like so:
KARMA_TEST_PATH=public/pages/x/specs/foo.spec.js karma start
and it will run that single test instead of all your specs.