|
| 1 | +--- |
| 2 | +mode:'agent' |
| 3 | +tools:['changes', 'codebase', 'editFiles', 'problems', 'search'] |
| 4 | +description:'Get best practices for TUnit unit testing, including data-driven tests' |
| 5 | +--- |
| 6 | + |
| 7 | +#TUnit Best Practices |
| 8 | + |
| 9 | +Your goal is to help me write effective unit tests with TUnit, covering both standard and data-driven testing approaches. |
| 10 | + |
| 11 | +##Project Setup |
| 12 | + |
| 13 | +- Use a separate test project with naming convention`[ProjectName].Tests` |
| 14 | +- Reference TUnit package and TUnit.Assertions for fluent assertions |
| 15 | +- Create test classes that match the classes being tested (e.g.,`CalculatorTests` for`Calculator`) |
| 16 | +- Use .NET SDK test commands:`dotnet test` for running tests |
| 17 | +- TUnit requires .NET 8.0 or higher |
| 18 | + |
| 19 | +##Test Structure |
| 20 | + |
| 21 | +- No test class attributes required (like xUnit/NUnit) |
| 22 | +- Use`[Test]` attribute for test methods (not`[Fact]` like xUnit) |
| 23 | +- Follow the Arrange-Act-Assert (AAA) pattern |
| 24 | +- Name tests using the pattern`MethodName_Scenario_ExpectedBehavior` |
| 25 | +- Use lifecycle hooks:`[Before(Test)]` for setup and`[After(Test)]` for teardown |
| 26 | +- Use`[Before(Class)]` and`[After(Class)]` for shared context between tests in a class |
| 27 | +- Use`[Before(Assembly)]` and`[After(Assembly)]` for shared context across test classes |
| 28 | +- TUnit supports advanced lifecycle hooks like`[Before(TestSession)]` and`[After(TestSession)]` |
| 29 | + |
| 30 | +##Standard Tests |
| 31 | + |
| 32 | +- Keep tests focused on a single behavior |
| 33 | +- Avoid testing multiple behaviors in one test method |
| 34 | +- Use TUnit's fluent assertion syntax with`await Assert.That()` |
| 35 | +- Include only the assertions needed to verify the test case |
| 36 | +- Make tests independent and idempotent (can run in any order) |
| 37 | +- Avoid test interdependencies (use`[DependsOn]` attribute if needed) |
| 38 | + |
| 39 | +##Data-Driven Tests |
| 40 | + |
| 41 | +- Use`[Arguments]` attribute for inline test data (equivalent to xUnit's`[InlineData]`) |
| 42 | +- Use`[MethodData]` for method-based test data (equivalent to xUnit's`[MemberData]`) |
| 43 | +- Use`[ClassData]` for class-based test data |
| 44 | +- Create custom data sources by implementing`ITestDataSource` |
| 45 | +- Use meaningful parameter names in data-driven tests |
| 46 | +- Multiple`[Arguments]` attributes can be applied to the same test method |
| 47 | + |
| 48 | +##Assertions |
| 49 | + |
| 50 | +- Use`await Assert.That(value).IsEqualTo(expected)` for value equality |
| 51 | +- Use`await Assert.That(value).IsSameReferenceAs(expected)` for reference equality |
| 52 | +- Use`await Assert.That(value).IsTrue()` or`await Assert.That(value).IsFalse()` for boolean conditions |
| 53 | +- Use`await Assert.That(collection).Contains(item)` or`await Assert.That(collection).DoesNotContain(item)` for collections |
| 54 | +- Use`await Assert.That(value).Matches(pattern)` for regex pattern matching |
| 55 | +- Use`await Assert.That(action).Throws<TException>()` or`await Assert.That(asyncAction).ThrowsAsync<TException>()` to test exceptions |
| 56 | +- Chain assertions with`.And` operator:`await Assert.That(value).IsNotNull().And.IsEqualTo(expected)` |
| 57 | +- Use`.Or` operator for alternative conditions:`await Assert.That(value).IsEqualTo(1).Or.IsEqualTo(2)` |
| 58 | +- Use`.Within(tolerance)` for DateTime and numeric comparisons with tolerance |
| 59 | +- All assertions are asynchronous and must be awaited |
| 60 | + |
| 61 | +##Advanced Features |
| 62 | + |
| 63 | +- Use`[Repeat(n)]` to repeat tests multiple times |
| 64 | +- Use`[Retry(n)]` for automatic retry on failure |
| 65 | +- Use`[ParallelLimit<T>]` to control parallel execution limits |
| 66 | +- Use`[Skip("reason")]` to skip tests conditionally |
| 67 | +- Use`[DependsOn(nameof(OtherTest))]` to create test dependencies |
| 68 | +- Use`[Timeout(milliseconds)]` to set test timeouts |
| 69 | +- Create custom attributes by extending TUnit's base attributes |
| 70 | + |
| 71 | +##Test Organization |
| 72 | + |
| 73 | +- Group tests by feature or component |
| 74 | +- Use`[Category("CategoryName")]` for test categorization |
| 75 | +- Use`[DisplayName("Custom Test Name")]` for custom test names |
| 76 | +- Consider using`TestContext` for test diagnostics and information |
| 77 | +- Use conditional attributes like custom`[WindowsOnly]` for platform-specific tests |
| 78 | + |
| 79 | +##Performance and Parallel Execution |
| 80 | + |
| 81 | +- TUnit runs tests in parallel by default (unlike xUnit which requires explicit configuration) |
| 82 | +- Use`[NotInParallel]` to disable parallel execution for specific tests |
| 83 | +- Use`[ParallelLimit<T>]` with custom limit classes to control concurrency |
| 84 | +- Tests within the same class run sequentially by default |
| 85 | +- Use`[Repeat(n)]` with`[ParallelLimit<T>]` for load testing scenarios |
| 86 | + |
| 87 | +##Migration from xUnit |
| 88 | + |
| 89 | +- Replace`[Fact]` with`[Test]` |
| 90 | +- Replace`[Theory]` with`[Test]` and use`[Arguments]` for data |
| 91 | +- Replace`[InlineData]` with`[Arguments]` |
| 92 | +- Replace`[MemberData]` with`[MethodData]` |
| 93 | +- Replace`Assert.Equal` with`await Assert.That(actual).IsEqualTo(expected)` |
| 94 | +- Replace`Assert.True` with`await Assert.That(condition).IsTrue()` |
| 95 | +- Replace`Assert.Throws<T>` with`await Assert.That(action).Throws<T>()` |
| 96 | +- Replace constructor/IDisposable with`[Before(Test)]`/`[After(Test)]` |
| 97 | +- Replace`IClassFixture<T>` with`[Before(Class)]`/`[After(Class)]` |
| 98 | + |
| 99 | +**Why TUnit over xUnit?** |
| 100 | + |
| 101 | +TUnit offers a modern, fast, and flexible testing experience with advanced features not present in xUnit, such as asynchronous assertions, more refined lifecycle hooks, and improved data-driven testing capabilities. TUnit's fluent assertions provide clearer and more expressive test validation, making it especially suitable for complex .NET projects. |