Fix S6966 FP: EntityFrameworks IDbContextFactory CreateDbContext method is preferred over its Async counterpart

Author: sebastien-marichal

analyzers/src/SonarAnalyzer.CSharp/Rules/UseAwaitableMethod.cs

@@ -95,6 +95,7 @@ private static ImmutableArray<Func<IMethodSymbol, bool>> BuildExclusions(Compila
         {
             exclusions.Add(x => x.IsAny(KnownType.Microsoft_EntityFrameworkCore_DbSet_TEntity, ExcludedMethodNames)); // https://github.com/SonarSource/sonar-dotnet/issues/9269
             exclusions.Add(x => x.IsAny(KnownType.Microsoft_EntityFrameworkCore_DbContext, ExcludedMethodNames));     // https://github.com/SonarSource/sonar-dotnet/issues/9269
+            exclusions.Add(x => x.IsImplementingInterfaceMember(KnownType.Microsoft_EntityFrameworkCore_IDbContextFactory_TContext, "CreateDbContext"));
         }
         if (compilation.GetTypeByMetadataName(KnownType.FluentValidation_IValidator) is not null)
         {
@@ -109,25 +110,25 @@ private static ImmutableArray<Func<IMethodSymbol, bool>> BuildExclusions(Compila
     }
 
     private static ImmutableArray<ISymbol> FindAwaitableAlternatives(WellKnownExtensionMethodContainer wellKnownExtensionMethodContainer, ImmutableArray<Func<IMethodSymbol, bool>> exclusions,
-        InvocationExpressionSyntax invocationExpression, SemanticModel semanticModel, ISymbol containingSymbol, CancellationToken cancel)
+        InvocationExpressionSyntax invocationExpression, SemanticModel model, ISymbol containingSymbol, CancellationToken cancel)
     {
         var awaitableRoot = GetAwaitableRootOfInvocation(invocationExpression);
         if (awaitableRoot is not { Parent: AwaitExpressionSyntax } // Invocation result is already awaited.
             && invocationExpression.EnclosingScope() is { } scope
             && IsAsyncCodeBlock(scope)
-            && semanticModel.GetSymbolInfo(invocationExpression, cancel).Symbol is IMethodSymbol { MethodKind: not MethodKind.DelegateInvoke } methodSymbol
+            && model.GetSymbolInfo(invocationExpression, cancel).Symbol is IMethodSymbol { MethodKind: not MethodKind.DelegateInvoke } methodSymbol
             && !(methodSymbol.IsAwaitableNonDynamic()  // The invoked method returns something awaitable (but it isn't awaited).
                 || methodSymbol.ContainingType.DerivesFromAny(ExcludedTypes))
             && !exclusions.Any(x => x(methodSymbol)))
         {
             // Perf: Before doing (expensive) speculative re-binding in SpeculativeBindCandidates, we check if there is an "..Async()" alternative in scope.
-            var invokedType = invocationExpression.Expression.GetLeftOfDot() is { } expression && semanticModel.GetTypeInfo(expression) is { Type: { } type }
+            var invokedType = invocationExpression.Expression.GetLeftOfDot() is { } expression && model.GetTypeInfo(expression) is { Type: { } type }
                 ? type // A dotted expression: Lookup the type, left of the dot (this may be different from methodSymbol.ContainingType)
                 : containingSymbol.ContainingType; // If not dotted, than the scope is the current type. Local function support is missing here.
             var members = GetMethodSymbolsInScope($"{methodSymbol.Name}Async", wellKnownExtensionMethodContainer, invokedType, methodSymbol.ContainingType);
             var awaitableCandidates = members.Where(x => x.IsAwaitableNonDynamic());
             // Get the method alternatives and exclude candidates that would resolve to the containing method (endless loop)
-            var awaitableAlternatives = SpeculativeBindCandidates(semanticModel, awaitableRoot, invocationExpression, awaitableCandidates)
+            var awaitableAlternatives = SpeculativeBindCandidates(model, awaitableRoot, invocationExpression, awaitableCandidates)
                 .Where(x => !containingSymbol.Equals(x))
                 .ToImmutableArray();
             return awaitableAlternatives;
@@ -148,15 +149,15 @@ private static IEnumerable<INamedTypeSymbol> WellKnownExtensionMethodContainer(W
             ? extensionMethodContainer
             : [];
 
-    private static IEnumerable<ISymbol> SpeculativeBindCandidates(SemanticModel semanticModel, SyntaxNode awaitableRoot,
+    private static IEnumerable<ISymbol> SpeculativeBindCandidates(SemanticModel model, SyntaxNode awaitableRoot,
         InvocationExpressionSyntax invocationExpression, IEnumerable<IMethodSymbol> awaitableCandidates) =>
         awaitableCandidates
             .Select(x => x.Name)
             .Distinct()
-            .Select(x => SpeculativeBindCandidate(semanticModel, x, awaitableRoot, invocationExpression))
+            .Select(x => SpeculativeBindCandidate(model, x, awaitableRoot, invocationExpression))
             .WhereNotNull();
 
-    private static IMethodSymbol SpeculativeBindCandidate(SemanticModel semanticModel, string candidateName, SyntaxNode awaitableRoot,
+    private static IMethodSymbol SpeculativeBindCandidate(SemanticModel model, string candidateName, SyntaxNode awaitableRoot,
         InvocationExpressionSyntax invocationExpression)
     {
         var invocationIdentifierName = invocationExpression.GetMethodCallIdentifier()?.Parent;
@@ -165,7 +166,7 @@ private static IMethodSymbol SpeculativeBindCandidate(SemanticModel semanticMode
             return null;
         }
         var invocationReplaced = ReplaceInvocation(awaitableRoot, invocationExpression, invocationIdentifierName, candidateName);
-        var speculativeSymbolInfo = semanticModel.GetSpeculativeSymbolInfo(invocationReplaced.SpanStart, invocationReplaced, SpeculativeBindingOption.BindAsExpression);
+        var speculativeSymbolInfo = model.GetSpeculativeSymbolInfo(invocationReplaced.SpanStart, invocationReplaced, SpeculativeBindingOption.BindAsExpression);
         var speculativeSymbol = speculativeSymbolInfo.Symbol as IMethodSymbol;
         return speculativeSymbol;
     }

analyzers/src/SonarAnalyzer.Common/Helpers/KnownType.cs

@@ -136,6 +136,7 @@ public sealed partial class KnownType
         public static readonly KnownType Microsoft_EntityFrameworkCore_DbContextOptionsBuilder = new("Microsoft.EntityFrameworkCore.DbContextOptionsBuilder");
         public static readonly KnownType Microsoft_EntityFrameworkCore_DbSet_TEntity = new("Microsoft.EntityFrameworkCore.DbSet", "TEntity");
         public static readonly KnownType Microsoft_EntityFrameworkCore_EntityFrameworkQueryableExtensions = new("Microsoft.EntityFrameworkCore.EntityFrameworkQueryableExtensions");
+        public static readonly KnownType Microsoft_EntityFrameworkCore_IDbContextFactory_TContext = new("Microsoft.EntityFrameworkCore.IDbContextFactory", "TContext");
         public static readonly KnownType Microsoft_EntityFrameworkCore_Migrations_Migration = new("Microsoft.EntityFrameworkCore.Migrations.Migration");
         public static readonly KnownType Microsoft_EntityFrameworkCore_MySQLDbContextOptionsExtensions = new("Microsoft.EntityFrameworkCore.MySQLDbContextOptionsExtensions");
         public static readonly KnownType Microsoft_EntityFrameworkCore_NpgsqlDbContextOptionsExtensions = new("Microsoft.EntityFrameworkCore.NpgsqlDbContextOptionsExtensions");

analyzers/tests/SonarAnalyzer.Test/TestCases/UseAwaitableMethod_EF.cs

@@ -79,3 +79,32 @@ public async Task DatabaseFacade(DatabaseFacade databaseFacade)
         databaseFacade.UseTransaction(null);                                                         // Noncompliant
     }
 }
+
+// https://github.com/SonarSource/sonar-dotnet/issues/9590
+public class Repro_9590
+{
+    public async Task DoSomeWork(IDbContextFactory<AppDbContext> factory, MyDbContextFactory factory2, NotADbContextFactory factory3)
+    {
+        using AppDbContext dbContext = factory.CreateDbContext(); // Compliant - CreateDbContextAsync is excluded
+        using AppDbContext dbContext2 = factory2.CreateDbContext(); // Compliant - CreateDbContextAsync is excluded
+        using AppDbContext dbContext3 = factory3.CreateDbContext(); // Noncompliant
+    }
+
+    public class MyDbContextFactory : IDbContextFactory<AppDbContext>
+    {
+        public AppDbContext CreateDbContext() => throw new NotImplementedException();
+
+        public Task<AppDbContext> CreateDbContextAsync() => throw new NotImplementedException();
+    }
+
+    public class NotADbContextFactory
+    {
+        public AppDbContext CreateDbContext() => throw new NotImplementedException();
+
+        public Task<AppDbContext> CreateDbContextAsync() => throw new NotImplementedException();
+    }
+
+    public class AppDbContext : DbContext
+    {
+    }
+}