ThinkMeta.CodeAnalysis.CSharp 1.0.6

ThinkMeta.CodeAnalysis

Static code analyzer for C#

ThinkMeta.CodeAnalysis.CSharp<br>

Overview

ThinkMeta.CodeAnalysis is a static code analyzer for C# projects, built on Roslyn. It helps developers identify code issues, enforce coding standards, and improve code quality automatically.

Features

• Detects common code issues and anti-patterns
• Supports custom analyzers and code fixes
• Integrates with .NET build and IDE tooling
• Targets .NET Standard 2.0 for broad compatibility

Diagnostics

TM0001: Use pattern matching for null checks

Description:
Warns when using == null or != null for null checks.
Reason:
Pattern matching (is null, is not null) is preferred for clarity and future-proofing code.
How to fix:
Replace == null with is null, and != null with is not null.

Exceptions:
Null checks using == null or != null inside expression trees (e.g., lambdas assigned to Expression<Func<...>>) are not reported by this diagnostic, as pattern matching is not supported in expression trees.

Examples:

// Standard null check
if (obj == null) { }
// =>
if (obj is null) { }

// Query syntax
var q = from o in arr where o == null select o;
// =>
var q = from o in arr where o is null select o;

// Razor-generated (in .g.cs from .razor)
@if (Model == null) { <text>Empty</text> }
// =>
@if (Model is null) { <text>Empty</text> }

// No warning in expression trees
Expression<Func<object, bool>> expr = o => o == null; // No diagnostic

TM0002: DeepCopy attribute usage violation

Description:
Reports errors when a method marked with [DeepCopy] does not follow required usage rules.

Reason:
Methods with [DeepCopy] must have exactly one parameter, and that parameter's type (and all nested types/collections, unless marked with [DeepCopyIgnore]) must be sealed.

How to fix:

• Ensure the method has only one parameter.
• The parameter type and all nested types/collections must be sealed (unless [DeepCopyIgnore] is used).

Examples:

// Violations:
class Bar {
    [DeepCopy]
    void Copy(int a, int b) { } // TM0002: Method must have exactly one parameter.
}

class Foo { }
class Bar {
    [DeepCopy]
    void Copy(Foo foo) { } // TM0002: Parameter type 'Foo' must be sealed.
}

class Inner { }
sealed class Outer { public Inner I; }
class Bar {
    [DeepCopy]
    void Copy(Outer outer) { } // TM0002: All nested types and collections must be sealed.
}

// Correct:
sealed class Inner { }
sealed class Outer { public Inner I; }
class Bar {
    [DeepCopy]
    void Copy(Outer outer) { } // OK
}

TM0003: DeepCopy method incomplete

Description:
Warns when a method marked with [DeepCopy] is incomplete, such as containing only a throw new NotImplementedException() or is empty.

Reason:
A [DeepCopy] method should provide a full implementation for deep copying the parameter.

How to fix:
Implement the method body to perform a deep copy of the parameter.

Examples:

class Bar {
    [DeepCopy]
    void Copy(Foo foo) {
        throw new NotImplementedException(); // TM0003: DeepCopy method incomplete.
    }
}

// Correct:
class Bar {
    [DeepCopy]
    void Copy(Foo foo) {
        // ... actual deep copy logic ...
    }
}