Testing the Add Method for Overwriting Data

This section outlines the approach used to test the Add method’s behavior when overwriting existing data in the collection.

Testing Scenarios

The tests focus on the following scenarios:

1. Overwriting Data: Ensuring the Add method replaces existing data when the collection hasn’t been overridden before.

Test Implementation

The tests are implemented using the xUnit testing framework, leveraging the following assertions:

• Assert.Equal: Verifies that the actual value matches the expected value.

Test Example: Overwriting Data

[Fact]
          public void Add_OverwritesExistingData()
          {
              // Arrange
              var list = new DefaultingList<string> { "Existing Value" };
              var expectedValue = "New Value";
          
              // Act
              list.Add(expectedValue);
          
              // Assert
              Assert.Equal(expectedValue, list[0]);
          }
          

In this example, the test sets up a DefaultingList<string> with an initial value. It then adds a new value using the Add method. Finally, it asserts that the first element of the list now contains the new value, verifying that the existing data has been overwritten.

This testing approach ensures the Add method behaves as expected when dealing with existing data, upholding the integrity of the DefaultingList class.