how to test Measure Power Consumption

To test the measure power consumption feature of the PlugSim class, you can create an instance of the class and call the measurePower() method multiple times with different inputs. You can also check the power field of the instance to see if it has been updated correctly after calling the measurePower() method.

For example, you can create a test case that turns on the plug, calls the measurePower() method multiple times, and checks if the power field is within a reasonable range. You can also create a test case that turns off the plug, calls the measurePower() method, and checks if the power field is zero.

Here's an example test case using JUnit 5 framework:

import org.junit.jupiter.api.Test;
import static org.junit.jupiter.api.Assertions.*;

public class PlugSimTest {

    @Test
    public void testMeasurePower() {
        PlugSim plug = new PlugSim("Test Plug");
        plug.switchOn();
        for (int i = 0; i < 10; i++) {
            plug.measurePower();
            double power = plug.getPower();
            assertTrue(power >= 0 && power <= 400, "Power reading out of range: " + power);
        }
    }

    @Test
    public void testMeasurePowerWhenOff() {
        PlugSim plug = new PlugSim("Test Plug");
        plug.switchOff();
        plug.measurePower();
        double power = plug.getPower();
        assertEquals(0, power, "Power reading should be zero when plug is off");
    }
}

In the first test case, we create a new PlugSim instance, turn it on, and call the measurePower() method 10 times. We check if the power reading is within the range of 0 to 400 watts, which is a reasonable range for a typical household appliance. In the second test case, we turn off the plug, call the measurePower() method, and check if the power reading is zero.