Testing Policy for Luxoria

Objective

The purpose of this testing policy is to establish a clear and robust framework for writing, organizing, and maintaining unit tests for the Luxoria project. This ensures consistent quality, high coverage, and minimal regressions throughout development.

Core Principles

High Coverage:
- Ensure all critical components and workflows are covered, including normal, edge, and error scenarios.
Test Isolation:
- Each unit test must run independently of others. External dependencies must be mocked or stubbed.
Performance:
- Tests should execute quickly to support continuous testing during development.
Readability:
- Test code should be self-explanatory, with clear naming conventions and comments where needed.
Ease of Maintenance:
- Tests must be straightforward to update as the code evolves. Avoid excessive coupling between tests and implementation details.

Test Structure

1. Organization

Tests should mirror the structure of the source code:
- Luxoria.Modules → Luxoria.Modules.Tests
Each class or module should have a dedicated test file named ClassNameTests.cs.

2. Naming Conventions

Tests should clearly describe their intent using the format:
- MethodName_StateUnderTest_ExpectedBehavior
- Example: Subscribe_WithValidHandler_ShouldAddSubscriber

3. Test Scenarios

Tests must cover:

Standard Cases: Typical input and expected behavior.
Edge Cases: Extreme conditions such as null values, empty lists, or large inputs.
Error Cases: Behavior when exceptions are expected or invalid data is provided.

Testing Best Practices

1. Use of Mocking

Use mocking libraries (e.g., Moq) to isolate dependencies.
Verify mock interactions to ensure proper communication between components.

2. Centralized Setup

Common dependencies should be initialized in a shared setup method (e.g., constructors or [SetUp] in test frameworks).

3. Assertions

Assertions must be explicit and descriptive to validate expected outcomes:
- Use Assert.Equal, Assert.NotNull, and Mock.Verify for clarity.

4. Test-Driven Development (TDD)

Write tests before implementing the functionality to capture business requirements effectively.

5. Handle Exceptional Scenarios

Ensure error handling paths are tested. For example:
- Validate proper exceptions are thrown for invalid inputs.
- Test fallback mechanisms where applicable.

Guidelines for Writing Unit Tests

1. Test File Template

A unit test file should follow this basic structure:

using Xunit;
using Moq;
using Luxoria.Modules;

namespace Luxoria.Modules.Tests
{
    public class ClassNameTests
    {
        private readonly ClassName _classUnderTest;

        public ClassNameTests()
        {
            _classUnderTest = new ClassName();
        }

        [Fact]
        public void MethodName_StateUnderTest_ExpectedBehavior()
        {
            // Arrange
            var mockDependency = new Mock<IDependency>();
            // Set up dependencies

            // Act
            var result = _classUnderTest.MethodUnderTest();

            // Assert
            Assert.NotNull(result);
        }
    }
}

2. Examples of Improved Test Cases

Case 1: Validating Null Handling

[Fact]
public void Subscribe_NullSubscriber_ShouldThrowArgumentNullException()
{
    // Arrange
    Action<LogEvent> nullSubscriber = null;

    // Act & Assert
    Assert.Throws<ArgumentNullException>(() => _eventBus.Subscribe(nullSubscriber));
}

Case 2: Testing State Changes

[Fact]
public void Unsubscribe_NonexistentSubscriber_ShouldNotThrow()
{
    // Arrange
    var mockSubscriber = new Mock<Action<LogEvent>>();

    // Act & Assert
    _eventBus.Unsubscribe(mockSubscriber.Object); // Should not throw
}

Continuous Integration and Testing Automation

Use CI tools (e.g., GitHub Actions, Jenkins) to run unit tests automatically on every commit.
Track test coverage metrics using tools like coverlet or dotCover.
Set thresholds for coverage to prevent regressions (e.g., 80% minimum).

Review Process

Code Reviews:
- All new test code must be reviewed by peers to ensure adherence to this policy.
Test Audits:
- Conduct periodic reviews to identify outdated or redundant tests and improve overall coverage.
Refactoring:
- Update tests whenever code is refactored to align with new implementations.

Monitoring and Metrics

Track the following metrics to ensure test quality:

Test Coverage: Percentage of code covered by tests.
Test Reliability: Percentage of flaky or unreliable tests.
Execution Time: Average time taken for tests to run.

This policy ensures consistency and scalability for the testing practices in Luxoria. With proper adherence, it will facilitate long-term project stability and maintainability.

Last updated 13 days ago