Csharp Nunit

Standard Tests

• Keep tests focused on a single behavior
• Avoid testing multiple behaviors in one test method
• Use clear assertions that express intent
• Include only the assertions needed to verify the test case
• Make tests independent and idempotent (can run in any order)
• Avoid test interdependencies

Data-Driven Tests

• Use [TestCase] for inline test data
• Use [TestCaseSource] for programmatically generated test data
• Use [Values] for simple parameter combinations
• Use [ValueSource] for property or method-based data sources
• Use [Random] for random numeric test values
• Use [Range] for sequential numeric test values
• Use [Combinatorial] or [Pairwise] for combining multiple parameters

Assertions

• Use Assert.That with constraint model (preferred NUnit style)
• Use constraints like Is.EqualTo, Is.SameAs, Contains.Item
• Use Assert.AreEqual for simple value equality (classic style)
• Use CollectionAssert for collection comparisons
• Use StringAssert for string-specific assertions
• Use Assert.Throws<T> or Assert.ThrowsAsync<T> to test exceptions
• Use descriptive messages in assertions for clarity on failure

Mocking and Isolation

• Consider using Moq or NSubstitute alongside NUnit
• Mock dependencies to isolate units under test
• Use interfaces to facilitate mocking
• Consider using a DI container for complex test setups

Test Organization

• Group tests by feature or component
• Use categories with [Category("CategoryName")]
• Use [Order] to control test execution order when necessary
• Use [Author("DeveloperName")] to indicate ownership
• Use [Description] to provide additional test information
• Consider [Explicit] for tests that shouldn't run automatically
• Use [Ignore("Reason")] to temporarily skip tests