Csharp-Mstest
Csharp-Mstest是一款code方向的AI技能，核心价值是Get best practices for MSTest 3，可用于解决开发者在code领域的实际问题，帮助用户提升效率、自动化重复任务或优化工作流。
Get best practices for MSTest 3.x/4.x unit testing, including modern assertion APIs and data-driven tests
mkdir -p ./skills/csharp-mstest && curl -sfL https://raw.githubusercontent.com/github/awesome-copilot/main/skills/csharp-mstest/SKILL.md -o ./skills/csharp-mstest/SKILL.mdRun in terminal / PowerShell. Requires curl (Unix) or PowerShell 5+ (Windows).
Skill Content
# MSTest Best Practices (MSTest 3.x/4.x)
Your goal is to help me write effective unit tests with modern MSTest, using current APIs and best practices.
Project Setup
- Use a separate test project with naming convention `[ProjectName].Tests`
- Reference MSTest 3.x+ NuGet packages (includes analyzers)
- Consider using MSTest.Sdk for simplified project setup
- Run tests with `dotnet test`
Test Class Structure
- Use `[TestClass]` attribute for test classes
- **Seal test classes by default** for performance and design clarity
- Use `[TestMethod]` for test methods (prefer over `[DataTestMethod]`)
- Follow Arrange-Act-Assert (AAA) pattern
- Name tests using pattern `MethodName_Scenario_ExpectedBehavior`
[TestClass]
public sealed class CalculatorTests
{
[TestMethod]
public void Add_TwoPositiveNumbers_ReturnsSum()
{
// Arrange
var calculator = new Calculator();
// Act
var result = calculator.Add(2, 3);
// Assert
Assert.AreEqual(5, result);
}
}Test Lifecycle
- **Prefer constructors over `[TestInitialize]`** - enables `readonly` fields and follows standard C# patterns
- Use `[TestCleanup]` for cleanup that must run even if test fails
- Combine constructor with async `[TestInitialize]` when async setup is needed
[TestClass]
public sealed class ServiceTests
{
private readonly MyService _service; // readonly enabled by constructor
public ServiceTests()
{
_service = new MyService();
}
[TestInitialize]
public async Task InitAsync()
{
// Use for async initialization only
await _service.WarmupAsync();
}
[TestCleanup]
public void Cleanup() => _service.Reset();
}Execution Order
1. **Assembly Initialization** - `[AssemblyInitialize]` (once per test assembly)
2. **Class Initialization** - `[ClassInitialize]` (once per test class)
3. **Test Initialization** (for every test method):
1. Constructor
2. Set `TestContext` property
3. `[TestInitialize]`
4. **Test Execution** - test method runs
5. **Test Cleanup** (for every test method):
1. `[TestCleanup]`
2. `DisposeAsync` (if implemented)
3. `Dispose` (if implemented)
6. **Class Cleanup** - `[ClassCleanup]` (once per test class)
7. **Assembly Cleanup** - `[AssemblyCleanup]` (once per test assembly)
Modern Assertion APIs
MSTest provides three assertion classes: `Assert`, `StringAssert`, and `CollectionAssert`.
Assert Class - Core Assertions
// Equality
Assert.AreEqual(expected, actual);
Assert.AreNotEqual(notExpected, actual);
Assert.AreSame(expectedObject, actualObject); // Reference equality
Assert.AreNotSame(notExpectedObject, actualObject);
// Null checks
Assert.IsNull(value);
Assert.IsNotNull(value);
// Boolean
Assert.IsTrue(condition);
Assert.IsFalse(condition);
// Fail/Inconclusive
Assert.Fail("Test failed due to...");
Assert.Inconclusive("Test cannot be completed because...");Exception Testing (Prefer over `[ExpectedException]`)
// Assert.Throws - matches TException or derived types
var ex = Assert.Throws<ArgumentException>(() => Method(null));
Assert.AreEqual("Value cannot be null.", ex.Message);
// Assert.ThrowsExactly - matches exact type only
var ex = Assert.ThrowsExactly<InvalidOperationException>(() => Method());
// Async versions
var ex = await Assert.ThrowsAsync<HttpRequestException>(async () => await client.GetAsync(url));
var ex = await Assert.ThrowsExactlyAsync<InvalidOperationException>(async () => await Method());Collection Assertions (Assert class)
Assert.Contains(expectedItem, collection);
Assert.DoesNotContain(unexpectedItem, collection);
Assert.ContainsSingle(collection); // exactly one element
Assert.HasCount(5, collection);
Assert.IsEmpty(collection);
Assert.IsNotEmpty(collection);String Assertions (Assert class)
Assert.Contains("expected", actualString);
Assert.StartsWith("prefix", 🎯 Best For
- QA engineers
- Developers writing unit tests
- Claude users
- GitHub Copilot users
- Software engineers
💡 Use Cases
- Generating test cases for edge conditions
- Writing integration test suites
- Code quality improvement
- Best practice enforcement
📖 How to Use This Skill
- 1
Install the Skill
Copy the install command from the Terminal tab and run it. The SKILL.md file downloads to your local skills directory.
- 2
Load into Your AI Assistant
Open Claude or GitHub Copilot and reference the skill. Paste the SKILL.md content or use the system prompt tab.
- 3
Apply Csharp-Mstest to Your Work
Open your project in the AI assistant and ask it to apply the skill. Start with a small module to verify the output quality.
- 4
Review and Refine
Review AI suggestions before committing. Run tests, check for regressions, and iterate on the skill output.
❓ Frequently Asked Questions
Does this generate test mocks?
Many testing skills include mock generation. Check the install command and skill content for details.
Is Csharp-Mstest compatible with Cursor and VS Code?
Yes — this skill works with any AI coding assistant including Cursor, VS Code with Copilot, and JetBrains IDEs.
Do I need specific dependencies for Csharp-Mstest?
Check the install command and Works With section. Most code skills only require the AI assistant and your codebase.
How do I install Csharp-Mstest?
Copy the install command from the Terminal tab and run it. The skill downloads to ./skills/csharp-mstest/SKILL.md, ready to use.
Can I customize this skill for my team?
Absolutely. Edit the SKILL.md file to add team-specific instructions, examples, or workflows.
⚠️ Common Mistakes to Avoid
Not testing edge cases
AI tends to generate happy-path tests. Manually review for boundary conditions.
Skipping validation
Always test AI-generated code changes, even for simple refactors.
Missing dependency updates
Check if the skill requires updated dependencies or new packages.