test: improve general code coverage

[Kenzoud]

This pull request introduces several new unit and UI tests to improve the app's overall line coverage:

Composable Tests:

• Added tests for ChangeAvatarButton to verify its conditional rendering and interaction logic based on avatar selection status.
• Added tests for SampleScreen to validate text display, back button functionality, and UI element presence using test tags.

Utility Tests:

• Wrote tests for the generateCircularGeometry method in GeometryUtils, ensuring correct vertex and index generation for circular shapes in OpenGL rendering.
• Added a test for the ShortArray.toBuffer() extension method in BufferUtils, verifying proper conversion of arrays to OpenGL-compatible buffers.

Class-Specific Tests:

• Added tests for the StarsLoader class to verify correct star data conversion and ensure interactions with the repository, including edge cases like empty star data lists.
• Added tests for the Camera class

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
100.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[rihabbelmekki]

Great work on expanding our test coverage! Approved for merge.

[Ismaillat]

Thank you for submitting these test classes. The overall implementation is thorough and demonstrates a clear understanding of the required functionality. Below are my observations:

Comprehensive Coverage:

The tests cover a wide range of scenarios, ensuring that critical functionalities are well-tested.
Edge cases, such as empty data lists or default states, are appropriately addressed (e.g., StarsLoaderTest and GeometryUtilsTest).

Clear Assertions:

Assertions are precise and meaningful, verifying the expected behavior effectively.
Use of assertArrayEquals and assertEquals ensures validation of both data structures and numerical results.

Mocking and Dependency Isolation:

Dependencies like repositories and context are mocked effectively, isolating the functionality under test.
Use of Mockito for mocking and verifying interactions adds robustness to the tests.

Utility Validation:

Utility methods, such as those in GeometryUtilsTest and BufferUtilsTest, are well-tested to ensure their correctness in handling data transformations.

Readable and Maintainable:

Each test is concise, self-contained, and adheres to best practices.
Test names are descriptive, making it easy to understand their purpose.

Validation of Complex Scenarios:

The billboard matrix calculation and circular geometry generation are non-trivial, yet the tests validate their outputs with clear expectations (GeometryUtilsTest).

These test classes are comprehensive and well-structured, ensuring high confidence in the associated functionality. The use of mocks, clear assertions, and meaningful edge-case handling reflects excellent test-writing practices. The PR is approved for merge.