Automated tests

The CometVisu uses two types of automated software tests: unittests and end-to-end tests. Unittest is about testing individual functions within the source code. If you e.g. has an add function that adds two numbers, then a unit test calls this function, passes two numbers to it and checks if the result is correct.

End-to-end tests tend to examine the “big picture” and simulate user retention. In this case, the CometVisu is opened fully automated in a browser and the tests operate the Visu as a user and check whether an action causes the desired changes. For example, one can Check if clicking on a switch returns the appropriate value to the backend and if the backend provides an update for the switch, it displays this accordingly.


The test runner for the tests is Karma. The tests are executed via the command line tool Grunt. If you have not already done so, the following commands must be executed in the root directory of the CometVisu project for preparation.

npm install
sudo npm -g install grunt-cli

The existing unit tests can then be executed with the following command:

grunt karma:travis

This carries out the tests including a code coverage analysis. The code coverage shows as a result of how many percent of the source code was covered by tests, the output looks like this:

=============================== Coverage summary ===============================
Statements   : 42.14% ( 1308/3104 )
Branches     : 32.35% ( 584/1805 )
Functions    : 46.99% ( 211/449 )
Lines        : 41.8% ( 1233/2950 )

For a more detailed coverage report, see ./coverage/<browser-name>/index.html.Where the browser name escapes that of the executing browser. Currently this is the headless testing (Chrome based) PhantomJS. Theoretically, all browsers installed on the local system are possible here. In the detailed coverage report, you can navigate down to individual source code files and see which lines have not yet been tested. This is very useful to see where the tests still need to be completed.

Write own tests

The unit tests are written using the Jasmine Framework This makes it possible to write the tests almost in natural language. The basic structure of a test looks like this:

describe("My testsuite", function() {
  it("should add two numbers", function() {
  expect(add(4, 5).toBe(9);

This code tests an add function that simply adds two numbers.

You can find the existing tests in the source/test/karma subdirectory. If you would like to write a new test for a (fictitious) source code file under source/ui/structure/pure/NewWidget.js, you will create the new file source/test/karma/ui/structure/pure/NewWidget-spec.js....

It is important that the name of the test file ends with -spec, otherwise it will not be found by the testrunner.

The test for this file should now look like this:

describe("testing the new-widget", function() {

  it("should test the creation of a new-widget", function() {
    // Auxiliary function that generates the HTML code of the widget (further help functions can be found in source / test / karma / helper-spec.js)
    // the helper returns an array of 2 elements, the first is the widget object, the second the HTML code as a string
    var res = this.createTestWidgetString("new-widget", {}, "<label>Test</label>");
    // turns the string into a DOM element
    var widget =[res[1]])[0];
    // Widget Object (instance of class cv.ui.structure.pure.NewWidget)
    var obj = res[0];

    // Check if the DOM element has the CSS class newwidget
    // Check if the DOM element has a label with the text 'Test'
    // Check if the widget path is 'id_0'

  it("should test another part of the new-widget", function() {
    // other tests



As examples of how to write tests and what things to test like, the existing tests should serve.