Unit Testing Examples

Creating tests from existing code

1. Move your editor cursor (not the mouse) over a class name and hit alt + Enter (Option + Enter for Mac?)
2. Choose "Create Test"
3. For "Testing Library", choose "JUnit4" from the dropdown
   • You will see an error that says "JUnit4 library not found in the module".
   • Click "Fix" and select the option to Copy 'JUnit' library files to and leave the default path as-is. This copies the necessary stuff we need in order to run unit tests.
4. Tests are expressed in a specific way in the code so that JUnit can find them:
   • Must be a public void method
   • Must have an @Test attribute

Classes

• SingleDayForecast is a simple class that keeps track of the high/low temps for the day, the percent chance of rain (as an int between 0 and 100), and the outlook for the day (e.g. "Sunny", "Partly Cloudy", etc.). It does not contain additional logic other than getting/setting the values of each property.
• MultiDayForecast keeps track of the single-day forecasts for an arbitrary number of days in the future (as an ArrayList. It also has a threshold for recommending a rain jacket; if the percent chance of rain on a particular day is greater than or equal to the threshold, it should recommend to the user that they wear a rain jacket on that day.

Car

• Car contains various components of the car, including its engine and safety system.
• Engine can be used to start and stop the car, fill the gas tank, and drive.
• SafetySystem keeps track of the all the safety features of the car.
• Airbag keeps track of an airbag in the car and whether it has been deployed.
• TirePressureSensor keeps track of the pressure for a single tire on the car, and whether the current pressure is within the safe range.