Add Unit Tests for LEDHelper Class

[yrlmanoharreddy]

Description:

We need to add unit tests for the LEDHelper class in the com.opensourcewithslu.outputdevices package. This is a "good-first-issue" because it involves creating unit tests, which is a manageable task for newcomers and essential for ensuring code reliability.

Tasks:

1. Setup Testing Framework:
   • Ensure that the project is configured to use JUnit and Mockito for unit testing.
   • Add necessary dependencies to build.gradle.
2. Create Unit Tests:
   • Test ledOn() Method:
     • Verify that the LED is turned on when it is currently off.
     • Ensure that the LED is not turned on if it is already on.
   • Test ledOff() Method:
     • Confirm that the LED is turned off when it is currently on.
     • Ensure that the LED is not turned off if it is already off.
   • Test switchState() Method:
     • Verify that the LED state is toggled correctly when it is currently on.
     • Confirm that the LED state is toggled correctly when it is currently off.
   • Test blink(int duration) Method:
     • Ensure that the blink method is called with the correct parameters.
3. Verify Logging:
   • Ensure that the appropriate log messages are generated for the ledOn() and ledOff() methods.

Acceptance Criteria:

• All unit tests for the LEDHelper class are added and passing.
• The tests should mock the DigitalOutput class to avoid actual hardware interaction.
• Ensure that all methods are tested for different scenarios as outlined