Let's now build and test. The following commands can be used to build, launch the steps in the background, and run the Cucumber test cases with a wire protocol, respectively:

cmake --build build

build/RPNCalculator/RPNCalculatorSteps &

cucumber RPNCalculator

The following screenshot demonstrates the procedure of building and executing the Cucumber test case:

Great! Our test scenario is all green now! Let's move on to our next test scenario.

Let's add a scenario in the feature file to test the subtraction operation, as follows:

The test output looks as follows:

We had seen this before, hadn't we?  I'm sure you guessed it right; the expected result is 85 whereas the actual result is 0, as we haven't added any support for subtraction yet. Now, let's add the necessary code to add the subtraction logic in our application:

With this code change, let's rerun the test case and see what the test outcome is:

Cool, the test report is back to green!

Let's move on and add a scenario in the feature file to test the multiplication operation:

It is time to the run the test case, as shown in the following screenshot:  

You got it right; yes, we need to add support for multiplication in our production code. Okay, let's do it right away, as shown in the following screenshot: