SatorImaging.StaticMemberAnalyzer 1.3.0

Static Field Analyzer for C# / .NET

Roslyn-based analyzer to provide diagnostics of static fields and properties initialization.

• Wrong order of static field and property declaration
• Partial type member reference across files
• Cross-Referencing Problem of static field across type
• Annotating / Underlining field, property or etc with custom message

Annotation for Type, Field and Property 💯

There is fancy extra feature to take your attention while coding in Visual Studio. No more need to use Obsolete attribute in case of annotating types, methods, fields and properties.

See the following section for details.

Installation

• NuGet
  • https://www.nuget.org/packages/SatorImaging.StaticMemberAnalyzer

  • PM> Install-Package SatorImaging.StaticMemberAnalyzer
    

Unity Integration

This analyzer can be used with Unity 2020.2 or above. See the following page for detail.

SatorImaging.StaticMemberAnalyzer.Unity/

Visual Studio 2019 or Earlier

Analyzer is tested on Visual Studio 2022.

You could use this analyzer on older versions of Visual Studio. To do so, update Vsix project file by following instructions written in memo and build project.

Cross-Referencing Problem

It is a design bug makes all things complex. Not only that but also it causes initialization error only when meet a specific condition.

So it must be fixed even if app works correctly at a moment, to prevent simple but complicated bug which is hard to find in large code base by hand. As you know static fields will never report error when initialization failed!!

It could be happened when reordering field declarations on refactoring large code base.

class A {
    public static int Value = B.Other;
    public static int Other = 310;
}

class B {
    public static int Other = 620;
    public static int Value = A.Other;  // will be '0' not '310'
}

public static class Test
{
    public static void Main()
    {
        System.Console.WriteLine(A.Value);  // 620
        System.Console.WriteLine(A.Other);  // 310
        System.Console.WriteLine(B.Value);  // 0   👈👈👈
        System.Console.WriteLine(B.Other);  // 620

        // when changing class member access order, it works correctly 🤣
        // see the following section for detailed explanation
        //System.Console.WriteLine(B.Value);  // 310  👈 correct!!
        //System.Console.WriteLine(B.Other);  // 620
        //System.Console.WriteLine(A.Value);  // 620
        //System.Console.WriteLine(A.Other);  // 310
    }
}

C# Compiler Initialization Sequence

• A.Value = B.Other;
  • // 'B' initialization is started by member access
  • B.Value = A.Other; // B.Value will be 0 because reading uninitialized A.Other
  • B.Other = 620;
  • // then, assign B.Other value (620) to A.Value
• A.Other = 310; // initialized here!! this value is not assigned to B.Value

When reading B value first, initialization order is changed and resulting value is also changed accordingly:

• B.Other = 620;
• B.Value = A.Other;
  • // 'A' initialization is started by member access
  • A.Value = B.Other; // correct: B.Other is initialized before reading value
  • A.Other = 310;

Annotating / Underlining

There is optional feature to draw underline on selected types, fields, properties, generic type/method arguments and parameters of method, delegate and lambda function.

Screenshot

As of Visual Studio's UX design, Info severity diagnostic underlines are drawn only on a few leading chars, not drawn whole marked area. So for workaround, underline on keyword is dashed.

[!TIP] !-starting message will add warning annotation on keyword instead of info diagnostic annotation.

[!NOTE] To draw underline, need to add <code>[Description<b><i>Attribute</i></b>("...")]</code> (full attribute class name) instead of suffix-less class name. When add [Description("...")] attribute, underline WON'T be drawn.

How to Use

To avoid dependency to this analyzer, required attribute is chosen from builtin System.ComponentModel assembly so that syntax is little bit weird.

Analyzer is checking identifier keyword in C# source code, not actual C# type. The text DescriptionAttribute in attribute syntax is only allowed to draw underline.

using System.ComponentModel;

[DescriptionAttribute("Draw underline for IDE environment and show this message")]
//          ^^^^^^^^^ `Attribute` suffix is required to draw underline
public class WithUnderline
{
    [DescriptionAttribute]  // parameter-less will draw underline with default message
    public static void Method() { }
}

// C# language spec allows to omit `Attribute` suffix but when omitted, underline won't be drawn
[Description("No Underline")]
public class NoUnderline { }

// underline won't be drawn when namespace is specified
[System.ComponentModel.DescriptionAttribute("...")]
public static int Underline_Not_Drawn = 0;

// this code will draw underline. 'Trivia' is allowed to being added in attribute syntax
[ /**/  DescriptionAttribute   (   "Underline will be drawn" )   /* hello, world. */   ]
public static int Underline_Drawn = 310;

Verbosity Control

There are 4 types of underline, line head, line leading, line end and keyword.

By default, static field analyzer will draw most verbose underline. You can omit specific type of underline by using #pragma preprocessor directive or adding SuppressMessage attribute to assembly, class or etc.

Unity Tips

Underlining is achieved by using Description attribute designed for Visual Studio's visual designer, formerly known as form designer.

To remove unnecessary attribute from Unity build, add the following link.xml file in Unity project's Assets folder.

<linker>
    <assembly fullname="System.ComponentModel">
        <type fullname="System.ComponentModel.DescriptionAttribute" preserve="nothing"/>
    </assembly>
</linker>