Enable nullable

src/Exercism.Analyzers.CSharp/Analysis.cs

@@ -1,5 +1,3 @@
-using System.Collections.Generic;
-
 using Exercism.Analyzers.CSharp.Analyzers;
 
 using Microsoft.CodeAnalysis;
@@ -12,14 +10,11 @@ internal record Analysis(List<Comment> Comments, List<string> Tags)
     public static Analysis Empty => new(new List<Comment>(), new List<string>());
 }
 
-internal abstract class Analyzer : CSharpSyntaxWalker
+internal abstract class Analyzer(Submission submission, SyntaxWalkerDepth syntaxWalkerDepth = SyntaxWalkerDepth.Token)
+    : CSharpSyntaxWalker(syntaxWalkerDepth)
 {
-    private readonly Submission _submission;
-    private SemanticModel _semanticModel;
-    private Analysis _analysis;
-
-    protected Analyzer(Submission submission, SyntaxWalkerDepth syntaxWalkerDepth = SyntaxWalkerDepth.Token) : base(syntaxWalkerDepth) => 
-        _submission = submission;
+    private SemanticModel? _semanticModel;
+    private Analysis? _analysis;
 
     public static Analysis Analyze(Submission submission)
     {
@@ -34,21 +29,21 @@ public static Analysis Analyze(Submission submission)
         return analysis;
     }
 
-    protected void AddComment(Comment comment) => _analysis.Comments.Add(comment);
+    protected void AddComment(Comment comment) => _analysis!.Comments.Add(comment);
 
     protected void AddTags(params string[] tags)
     {
         foreach (var tag in tags)
-            _analysis.Tags.Add(tag);
+            _analysis!.Tags.Add(tag);
     }
 
     private void Analyze(Analysis analysis)
     {
         _analysis = analysis;
 
-        foreach (var syntaxTree in _submission.Compilation.SyntaxTrees)
+        foreach (var syntaxTree in submission.Compilation.SyntaxTrees)
         {
-            _semanticModel = _submission.Compilation.GetSemanticModel(syntaxTree);
+            _semanticModel = submission.Compilation.GetSemanticModel(syntaxTree);
             Visit(syntaxTree.GetRoot());
         }
     }
@@ -102,17 +97,17 @@ public static IEnumerable<Analyzer> CreateAnalyzers(Submission submission)
         }
     }
 
-    protected SymbolInfo GetSymbolInfo(SyntaxNode node) => _semanticModel.GetSymbolInfo(node);
-    protected ISymbol GetSymbol(SyntaxNode node) => GetSymbolInfo(node).Symbol;
-    protected string GetSymbolName(SyntaxNode node) => GetSymbol(node)?.ToDisplayString();
+    protected SymbolInfo GetSymbolInfo(SyntaxNode node) => _semanticModel!.GetSymbolInfo(node);
+    protected ISymbol? GetSymbol(SyntaxNode node) => GetSymbolInfo(node).Symbol;
+    protected string? GetSymbolName(SyntaxNode node) => GetSymbol(node)?.ToDisplayString();
 
-    protected ISymbol GetDeclaredSymbol(SyntaxNode node) => _semanticModel.GetDeclaredSymbol(node);
-    protected string GetDeclaredSymbolName(SyntaxNode node) => GetDeclaredSymbol(node)?.ToDisplayString();
+    protected ISymbol? GetDeclaredSymbol(SyntaxNode node) => _semanticModel!.GetDeclaredSymbol(node);
+    protected string? GetDeclaredSymbolName(SyntaxNode node) => GetDeclaredSymbol(node)?.ToDisplayString();
 
-    protected TypeInfo GetTypeInfo(SyntaxNode node) => _semanticModel.GetTypeInfo(node);
-    protected IOperation GetOperation(SyntaxNode node) => _semanticModel.GetOperation(node);
+    protected TypeInfo GetTypeInfo(SyntaxNode node) => _semanticModel!.GetTypeInfo(node);
+    protected IOperation? GetOperation(SyntaxNode node) => _semanticModel!.GetOperation(node);
 
-    protected IMethodSymbol GetConstructedFromSymbol(SyntaxNode node) =>
+    protected IMethodSymbol? GetConstructedFromSymbol(SyntaxNode node) =>
         GetSymbol(node) is IMethodSymbol methodSymbol ? methodSymbol.ConstructedFrom : null;
-    protected string GetConstructedFromSymbolName(SyntaxNode node) => GetConstructedFromSymbol(node)?.ToDisplayString();
+    protected string? GetConstructedFromSymbolName(SyntaxNode node) => GetConstructedFromSymbol(node)?.ToDisplayString();
 }

src/Exercism.Analyzers.CSharp/Analyzers/CollatzConjectureAnalyzer.cs

@@ -2,12 +2,8 @@
 
 namespace Exercism.Analyzers.CSharp.Analyzers;
 
-internal class CollatzConjectureAnalyzer : Analyzer
+internal class CollatzConjectureAnalyzer(Submission submission) : Analyzer(submission)
 {
-    public CollatzConjectureAnalyzer(Submission submission) : base(submission)
-    {
-    }
-
     public override void VisitInvocationExpression(InvocationExpressionSyntax node)
     {
         if (GetConstructedFromSymbolName(node) == "System.Collections.Generic.IEnumerable<TSource>.Count<TSource>()")

src/Exercism.Analyzers.CSharp/Analyzers/CommonAnalyzer.cs

@@ -1,13 +1,10 @@
-using System.Collections.Generic;
-using System.Linq;
-
-using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.CSharp;
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 
 namespace Exercism.Analyzers.CSharp.Analyzers;
 
-internal class CommonAnalyzer : Analyzer
+internal class CommonAnalyzer(Submission submission) : Analyzer(submission)
 {
     public override void VisitMethodDeclaration(MethodDeclarationSyntax node)
     {
@@ -90,10 +87,6 @@ public override void VisitAssignmentExpression(AssignmentExpressionSyntax node)
         "Console.Out.WriteLine"
     };
 
-    public CommonAnalyzer(Submission submission) : base(submission)
-    {
-    }
-
     private static class Comments
     {
         public static readonly Comment DoNotUseMainMethod = new("csharp.general.has_main_method", CommentType.Essential);

src/Exercism.Analyzers.CSharp/Analyzers/DifferenceOfSquaresAnalyzer.cs

@@ -1,22 +1,16 @@
-using System.Linq;
-
-using Microsoft.CodeAnalysis.CSharp.Syntax;
+using Microsoft.CodeAnalysis.CSharp.Syntax;
 
 namespace Exercism.Analyzers.CSharp.Analyzers;
 
-internal class DifferenceOfSquaresAnalyzer : Analyzer
+internal class DifferenceOfSquaresAnalyzer(Submission submission) : Analyzer(submission)
 {
-    public DifferenceOfSquaresAnalyzer(Submission submission) : base(submission)
-    {
-    }
-
     public override void VisitMethodDeclaration(MethodDeclarationSyntax node)
     {
         if (node.DescendantNodes()
             .OfType<InvocationExpressionSyntax>()
             .Select(GetSymbol)
             .Where(invocationSymbol => invocationSymbol is not null)
-            .All(invocationSymbol => invocationSymbol.ContainingType.ToDisplayString() == "System.Math"))
+            .All(invocationSymbol => invocationSymbol?.ContainingType.ToDisplayString() == "System.Math"))
             AddTags(Tags.TechniqueMath);
 
         base.VisitMethodDeclaration(node);

src/Exercism.Analyzers.CSharp/Analyzers/GigasecondAnalyzer.cs

@@ -1,22 +1,16 @@
-using System.Linq;
-
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 
 namespace Exercism.Analyzers.CSharp.Analyzers;
 
-internal class GigasecondAnalyzer : Analyzer
+internal class GigasecondAnalyzer(Submission submission) : Analyzer(submission)
 {
-    public GigasecondAnalyzer(Submission submission) : base(submission)
-    {
-    }
-
     public override void VisitCompilationUnit(CompilationUnitSyntax node)
     {
         if (node.DescendantNodes()
                 .OfType<InvocationExpressionSyntax>()
                 .Select(GetSymbol)
                 .Where(symbol => symbol is not null)
-                .All(symbol => symbol.ToDisplayString() != "System.DateTime.AddSeconds(double)"))
+                .All(symbol => symbol?.ToDisplayString() != "System.DateTime.AddSeconds(double)"))
             AddComment(Comments.UseAddSeconds);
 
         base.VisitCompilationUnit(node);

src/Exercism.Analyzers.CSharp/Analyzers/GrainsAnalyzer.cs

@@ -2,12 +2,8 @@
 
 namespace Exercism.Analyzers.CSharp.Analyzers;
 
-internal class GrainsAnalyzer : Analyzer
+internal class GrainsAnalyzer(Submission submission) : Analyzer(submission)
 {
-    public GrainsAnalyzer(Submission submission) : base(submission)
-    {
-    }
-
     public override void VisitInvocationExpression(InvocationExpressionSyntax node)
     {
         if (GetSymbolName(node.Expression) == "System.Math.Pow(double, double)")

src/Exercism.Analyzers.CSharp/Analyzers/IsogramAnalyzer.cs

@@ -3,12 +3,8 @@
 
 namespace Exercism.Analyzers.CSharp.Analyzers;
 
-internal class IsogramAnalyzer : Analyzer
-{    
-    public IsogramAnalyzer(Submission submission) : base(submission)
-    {
-    }
-
+internal class IsogramAnalyzer(Submission submission) : Analyzer(submission)
+{
     public override void VisitInvocationExpression(InvocationExpressionSyntax node)
     {
         if (GetSymbolInfo(node).Symbol is IMethodSymbol methodSymbol)

src/Exercism.Analyzers.CSharp/Analyzers/LeapAnalyzer.cs

@@ -1,16 +1,10 @@
-using System.Linq;
-
-using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 
 namespace Exercism.Analyzers.CSharp.Analyzers;
 
-internal class LeapAnalyzer : Analyzer
+internal class LeapAnalyzer(Submission submission) : Analyzer(submission)
 {
-    public LeapAnalyzer(Submission submission) : base(submission)
-    {
-    }
-
     public override void VisitMethodDeclaration(MethodDeclarationSyntax node)
     {
         if (GetDeclaredSymbolName(node) == "Leap.IsLeapYear(int)" && 

src/Exercism.Analyzers.CSharp/Analyzers/PangramAnalyzer.cs

@@ -2,12 +2,8 @@
 
 namespace Exercism.Analyzers.CSharp.Analyzers;
 
-internal class PangramAnalyzer : Analyzer
-{    
-    public PangramAnalyzer(Submission submission) : base(submission)
-    {
-    }
-
+internal class PangramAnalyzer(Submission submission) : Analyzer(submission)
+{
     public override void VisitInvocationExpression(InvocationExpressionSyntax node)
     {
         switch (GetSymbolName(node))

src/Exercism.Analyzers.CSharp/Analyzers/ProteinTranslationAnalyzer.cs

@@ -2,12 +2,8 @@
 
 namespace Exercism.Analyzers.CSharp.Analyzers;
 
-internal class ProteinTranslationAnalyzer : Analyzer
-{    
-    public ProteinTranslationAnalyzer(Submission submission) : base(submission)
-    {
-    }
-
+internal class ProteinTranslationAnalyzer(Submission submission) : Analyzer(submission)
+{
     public override void VisitInvocationExpression(InvocationExpressionSyntax node)
     {
         switch (GetSymbolName(node))

src/Exercism.Analyzers.CSharp/Analyzers/RaindropsAnalyzer.cs

@@ -3,12 +3,8 @@
 
 namespace Exercism.Analyzers.CSharp.Analyzers;
 
-internal class RaindropsAnalyzer : Analyzer
+internal class RaindropsAnalyzer(Submission submission) : Analyzer(submission)
 {
-    public RaindropsAnalyzer(Submission submission) : base(submission)
-    {
-    }
-
     public override void VisitInvocationExpression(InvocationExpressionSyntax node)
     {
         if (GetSymbol(node) is IMethodSymbol methodSymbol && 

src/Exercism.Analyzers.CSharp/Analyzers/ReverseStringAnalyzer.cs

@@ -2,12 +2,8 @@
 
 namespace Exercism.Analyzers.CSharp.Analyzers;
 
-internal class ReverseStringAnalyzer : Analyzer
+internal class ReverseStringAnalyzer(Submission submission) : Analyzer(submission)
 {
-    public ReverseStringAnalyzer(Submission submission) : base(submission)
-    {
-    }
-
     public override void VisitInvocationExpression(InvocationExpressionSyntax node)
     {
         if (GetConstructedFromSymbolName(node) == "System.Array.Reverse<T>(T[])")

src/Exercism.Analyzers.CSharp/Analyzers/TagAnalyzer.cs

@@ -1,20 +1,12 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-
 using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.CSharp;
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Microsoft.CodeAnalysis.Operations;
 
 namespace Exercism.Analyzers.CSharp.Analyzers;
 
-internal class TagAnalyzer : Analyzer
+internal class TagAnalyzer(Submission submission) : Analyzer(submission, SyntaxWalkerDepth.Trivia)
 {
-    public TagAnalyzer(Submission submission) : base(submission, SyntaxWalkerDepth.Trivia)
-    {
-    }
-
     public override void VisitForStatement(ForStatementSyntax node)
     {
         AddTags(Tags.ConstructForLoop, Tags.TechniqueLooping);
@@ -204,7 +196,7 @@ public override void VisitInvocationExpression(InvocationExpressionSyntax node)
     {
         AddTags(Tags.ConstructInvocation, Tags.ConstructMethod);
 
-        if (GetSymbol(node) is not null && GetSymbol(node).ContainingNamespace.ToDisplayString() == "System.Linq")
+        if (GetSymbol(node)?.ContainingNamespace.ToDisplayString() == "System.Linq")
             AddTags(Tags.ConstructLinq, Tags.ParadigmFunctional);
 
         if (GetSymbolName(node) == "object.GetType()")

src/Exercism.Analyzers.CSharp/Analyzers/TwoFerAnalyzer.cs

@@ -2,12 +2,8 @@
 
 namespace Exercism.Analyzers.CSharp.Analyzers;
 
-internal class TwoFerAnalyzer : Analyzer
+internal class TwoFerAnalyzer(Submission submission) : Analyzer(submission)
 {
-    public TwoFerAnalyzer(Submission submission) : base(submission)
-    {
-    }
-
     public override void VisitMethodDeclaration(MethodDeclarationSyntax node)
     {
         switch (GetDeclaredSymbolName(node))

src/Exercism.Analyzers.CSharp/Analyzers/WeighingMachineAnalyzer.cs

@@ -1,24 +1,18 @@
-using System.Linq;
-
-using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.CSharp;
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 
 namespace Exercism.Analyzers.CSharp.Analyzers;
 
-internal class WeighingMachineAnalyzer : Analyzer
+internal class WeighingMachineAnalyzer(Submission submission) : Analyzer(submission)
 {
-    public WeighingMachineAnalyzer(Submission submission) : base(submission)
-    {
-    }
-
     public override void VisitPropertyDeclaration(PropertyDeclarationSyntax node)
     {
         switch (GetDeclaredSymbolName(node))
         {
             case "WeighingMachine.DisplayWeight":
             {
-                SyntaxNode getter = node.ExpressionBody == null
+                SyntaxNode? getter = node.ExpressionBody == null
                     ? node.DescendantNodes()
                         .OfType<AccessorDeclarationSyntax>()
                         .FirstOrDefault(

src/Exercism.Analyzers.CSharp/Exercism.Analyzers.CSharp.csproj

@@ -4,6 +4,8 @@
     <TargetFramework>net10.0</TargetFramework>
     <OutputType>Exe</OutputType>
     <PublishReadyToRun>true</PublishReadyToRun>
+    <Nullable>enable</Nullable>
+    <ImplicitUsings>enable</ImplicitUsings>
   </PropertyGroup>
 
   <ItemGroup>

src/Exercism.Analyzers.CSharp/Loader.cs

@@ -1,10 +1,5 @@
-using System;
-using System.Collections.Generic;
-using System.IO;
-using System.Linq;
 using System.Text.Json;
 using System.Text.Json.Nodes;
-using System.Threading.Tasks;
 
 using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.CSharp;
@@ -51,7 +46,7 @@ private static HashSet<string> NonSubmissionFiles(Options options)
 
             return nonSubmissionFileKeys
                 .Where(filesConfig.ContainsKey)
-                .SelectMany(key => filesConfig[key].Deserialize<IEnumerable<string>>())
+                .SelectMany(key => filesConfig[key].Deserialize<IEnumerable<string>>()!)
                 .Select(relativePath => Path.Combine(options.InputDirectory, relativePath))
                 .ToHashSet();
         }
@@ -77,7 +72,7 @@ private static CSharpCompilationOptions CompilationOptions() =>
             new(OutputKind.DynamicallyLinkedLibrary, optimizationLevel: OptimizationLevel.Debug);
 
         private static IEnumerable<MetadataReference> References() =>
-            ((string)AppContext.GetData("TRUSTED_PLATFORM_ASSEMBLIES"))!.Split(Path.PathSeparator)
+            ((string)AppContext.GetData("TRUSTED_PLATFORM_ASSEMBLIES")!).Split(Path.PathSeparator)
             .Select(p => MetadataReference.CreateFromFile(p));
     }
 }

src/Exercism.Analyzers.CSharp/Output.cs

@@ -1,7 +1,3 @@
-using System;
-using System.Collections.Generic;
-using System.IO;
-using System.Linq;
 using System.Text;
 using System.Text.Encodings.Web;
 using System.Text.Json;