CSharpExtensions

Nuget packge: https://www.nuget.org/packages/SmartAnalyzers.CSharpExtensions.Annotations/

Articles that explain implemented concepts:

• Immutable types in C# with Roslyn
• Improving non-nullable reference types handling
• Twin types - properties synchronization without inheritance
• Pure functions and unused return values

Analyzers

Rule	Description	Related attributes	Documentation
CSE001	Required properties initialization	[InitRequired], [InitRequiredForNotNull]	link
CSE002	InitOnly member modification	[InitOnly], [InitOnlyOptional]	link
CSE003	Type should have the same fields as twin type	[TwinType]	link
CSE004	Member with InitOnlyOptional requires default value	[InitOnlyOptional]
CSE005	Return value unused		link
CSE006	Expression too complex
CSE007	Return disposable value unused		Same as SE005 but tracks only IDisposable and IAsyncDisposable values
CSE008	Return async result unused		Same as SE005 but tracks only IAsyncResult (Task, ValueTask) values
CSE009	Task variable not awaited		Check if task stored in a variable is awaited

Configuration

Add CSharpExtensions.json file with custom configuration:

{
  "CSE005": {
    "IgnoredReturnTypes": [ 
        "Microsoft.Extensions.DependencyInjection.IServiceCollection",
        "Microsoft.Extensions.Configuration.IConfigurationBuilder",
        "Microsoft.Extensions.Logging.ILoggingBuilder"
        ] 
  } 
}

Include config file as AdditionalFile in csproj:

<ItemGroup>
    <AdditionalFiles Include="CSharpExtensions.json" />
</ItemGroup>

Migrating from Constructors to Initialization Blocks

Step 1: Configure CSharpExtensions to report CSE001 even when constructor invocation is present

{
  "CSE001": {
    "SkipWhenConstructorUsed":  false 
  } 
}

Step 2: Execute "Try to move initialization from constructor to init block" CodeFix for CSE001 occurrences.

Init-related attributes vs init keyword (C# 9+ feature)

Feature	Required in init block	Can be modified outside init block	Application level
init keyword	NO	NO	Property
[InitRequired]	YES	YES	Property. Class
[InitOnly]	YES	NO	Property. Class
[InitOnlyOptional]	NO	NO	Property. Class
[InitRequiredForNotNull]	YES for non-null references and not Nullable<T>	YES	assembly