ANcpLua.Analyzers 1.5.3

ANcpLua.Analyzers

Roslyn analyzers for C# code quality, focusing on modern .NET patterns and best practices. Catches common mistakes at compile time with actionable diagnostics and automatic code fixes.

Layer 2 Package: This is a downstream package that uses ANcpLua.NET.Sdk for its build infrastructure. If you use ANcpLua.NET.Sdk, this analyzer package is auto-injected to all your projects.

Installation

dotnet add package ANcpLua.Analyzers

Or add to your project file:

<PackageReference Include="ANcpLua.Analyzers" PrivateAssets="all" />

Rules

Legend: ❌ Error · ⚠️ Warning · ℹ️ Info

Configuration

Configure rule severity in your .editorconfig:

[*.cs]
# AL0001: Prohibit reassignment of primary constructor parameters
dotnet_diagnostic.AL0001.severity = error

# AL0002: Don't repeat negated patterns
dotnet_diagnostic.AL0002.severity = warning

# AL0003: Don't divide by constant zero
dotnet_diagnostic.AL0003.severity = error

# AL0004: Use pattern matching for Span constant comparison
dotnet_diagnostic.AL0004.severity = warning

# AL0005: Use SequenceEqual for Span non-constant comparison
dotnet_diagnostic.AL0005.severity = warning

# AL0006: Field name conflicts with primary constructor parameter
dotnet_diagnostic.AL0006.severity = warning

# AL0007: GetSchema should be explicitly implemented
dotnet_diagnostic.AL0007.severity = warning

# AL0008: GetSchema must return null and not be abstract
dotnet_diagnostic.AL0008.severity = warning

# AL0009: Don't call IXmlSerializable.GetSchema
dotnet_diagnostic.AL0009.severity = warning

# AL0010: Type should be partial for source generator support
dotnet_diagnostic.AL0010.severity = none

# AL0011: Avoid lock keyword on non-Lock types
dotnet_diagnostic.AL0011.severity = warning

# AL0012: Deprecated semantic convention attribute
dotnet_diagnostic.AL0012.severity = warning

# AL0013: Missing telemetry schema URL
dotnet_diagnostic.AL0013.severity = suggestion

# AL0014: Prefer pattern matching for null and zero comparisons
dotnet_diagnostic.AL0014.severity = suggestion

# AL0015: Normalize null-guard style
dotnet_diagnostic.AL0015.severity = suggestion

# AL0016: Combine declaration with subsequent null-check
dotnet_diagnostic.AL0016.severity = suggestion

# AL0017: Hardcoded package version
dotnet_diagnostic.AL0017.severity = warning

# AL0020-AL0024: ASP.NET Core form binding
dotnet_diagnostic.AL0020.severity = error
dotnet_diagnostic.AL0021.severity = error
dotnet_diagnostic.AL0022.severity = error
dotnet_diagnostic.AL0023.severity = error
dotnet_diagnostic.AL0024.severity = error

Examples

AL0001: Primary Constructor Parameter Reassignment

// Error: Primary constructor parameter 'x' should not be reassigned
public class Example(int x)
{
    public void SetX(int value) => x = value;  // AL0001
}

// Fix: Use a separate field
public class Example(int x)
{
    private int _x = x;
    public void SetX(int value) => _x = value;
}

AL0014: Pattern Matching for Null and Zero Comparisons

// Before: AL0014 triggered
if (x == null) { }
if (x != null) { }
if (count == 0) { }
if (count != 0) { }

// After: Use pattern matching
if (x is null) { }
if (x is not null) { }
if (count is 0) { }
if (count is not 0) { }

Note: This analyzer skips code inside expression trees (Expression<T>) where pattern matching is not supported.

ANcpLua.NET.Sdk Integration

This analyzer is auto-injected when using ANcpLua.NET.Sdk:

<Project Sdk="ANcpLua.NET.Sdk" />

SDK Features You Get "For Free"

Guard Clauses (Auto-Injected)

// Available in all SDK projects - replaces ArgumentNullException.ThrowIfNull
public void Process(string name, List<int> items)
{
    Throw.IfNull(name);                // Auto-captures param name
    Throw.IfNullOrEmpty(items);        // Works on collections
    Throw.IfNullOrWhitespace(name);    // String validation
    Throw.IfOutOfRange(myEnum);        // Enum validation
    Throw.IfLessThan(count, 0);        // Range checks
}

Test Base Classes (SDK Test Projects)

// Analyzer testing - pre-configured with .NET 10 reference assemblies
public class MyAnalyzerTests : AnalyzerTest<MyDiagnosticAnalyzer>
{
    [Fact]
    public Task DetectsIssue() => VerifyAsync("class C { int x = 1 / 0; }");
}

// Integration testing - WebApplicationFactory + FakeLogCollector
public class ApiTests : IntegrationTestBase<Program>
{
    [Fact]
    public async Task GetUsers_ReturnsOk()
    {
        var response = await Client.GetAsync("/api/users");
        response.StatusCode.Should().Be(HttpStatusCode.OK);
    }
}

Related Projects

• ANcpLua.NET.Sdk - MSBuild SDK that auto-injects this analyzer
• ANcpLua.Roslyn.Utilities - Roslyn utilities for source generators

License

MIT