Fix analyzer crash on unbound generic types

This was due to a bug where the analyzer would continue even if only unbound generic types were used in the typeof operator.
dotnet · Mar 15, 2024 · 50c9eb9 · 50c9eb9
1 parent 2e80d61
commit 50c9eb9
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Showing 2 changed files with 51 additions and 2 deletions.
diff --git a/src/NetAnalyzers/Core/Microsoft.NetCore.Analyzers/Usage/PreferGenericOverloads.cs b/src/NetAnalyzers/Core/Microsoft.NetCore.Analyzers/Usage/PreferGenericOverloads.cs
@@ -128,8 +128,8 @@ static bool AreNullabilityConstraintsViolated(IMethodSymbol method)
                             method.TypeArguments[i].CanHoldNullValue())
                         {
                             return true;
-            }
-        }
+                        }
+                    }
 
                     return false;
                 }
@@ -169,6 +169,13 @@ public static bool TryGetContext(IInvocationOperation invocation, [NotNullWhen(t
                     .Select(t => t.TypeOperand)
                     .Where(t => t is not INamedTypeSymbol { IsUnboundGenericType: true })
                     .ToImmutableArray();
+
+                // Bail out if there are no type arguments left after filtering out unbound generic types.
+                if (typeArguments.Length == 0)
+                {
+                    return false;
+                }
+
                 var otherArguments = argumentsInParameterOrder.RemoveRange(typeOfArguments);
 
                 invocationContext = new RuntimeTypeInvocationContext(invocation, typeArguments, otherArguments);

diff --git a/src/NetAnalyzers/UnitTests/Microsoft.NetCore.Analyzers/Usage/PreferGenericOverloadsTests.cs b/src/NetAnalyzers/UnitTests/Microsoft.NetCore.Analyzers/Usage/PreferGenericOverloadsTests.cs
@@ -93,6 +93,28 @@ void Test()
             await VerifyCS.VerifyCodeFixAsync(source, source);
         }
 
+        [Fact, WorkItem(7246, "https://github.com/dotnet/roslyn-analyzers/issues/7246")]
+        public async Task UnboundGenericTypeArgumentWithMatchingOtherArguments_NoDiagnostic_CS()
+        {
+            string source = """
+                class ViolatingType<T> {}
+
+                class C
+                {
+                    void M(System.Type type, object other) {}
+                    void M<T>() {}
+                    void M(object other) {}
+
+                    void Test()
+                    {
+                        M(typeof(ViolatingType<>), null);
+                    }
+                }
+                """;
+
+            await VerifyCS.VerifyCodeFixAsync(source, source);
+        }
+
         [Fact]
         public async Task WrongArity_NoDiagnostic_CS()
         {
@@ -1463,6 +1485,26 @@ End Class
             await VerifyVB.VerifyCodeFixAsync(source, source);
         }
 
+        [Fact, WorkItem(7246, "https://github.com/dotnet/roslyn-analyzers/issues/7246")]
+        public async Task UnboundGenericTypeArgumentWithMatchingOtherArguments_NoDiagnostic_VB()
+        {
+            string source = """
+                Class ViolatingType(Of T) : End Class
+
+                Class C
+                    Sub M(type as System.Type, other as Object) : End Sub
+                    Sub M(Of T)() : End Sub
+                    Sub M(other as Object) : End Sub
+
+                    Sub Test()
+                        M(GetType(ViolatingType(Of )))
+                    End Sub
+                End Class
+                """;
+
+            await VerifyVB.VerifyCodeFixAsync(source, source);
+        }
+
         [Fact]
         public async Task WrongArity_NoDiagnostic_VB()
         {