Making the variable naming watch out for key words because of course …

…someone tried to do just that

src/CodegenTests/Codegen/VariableTests.cs

@@ -122,6 +122,12 @@ public void default_arg_name_of_inner_interface()
         Variable.DefaultArgName<HyperdriveMotivator.IInnerThing>()
             .ShouldBe("innerThing");
     }
+
+    [Fact]
+    public void custom_lock_classes()
+    {
+        Variable.DefaultArgName<Lock>().ShouldBe("@lock");
+    }
 
 }
 
@@ -156,4 +162,7 @@ public class InnerThing
     public interface IInnerThing
     {
     }
-}
+}
+
+// Because of course, someone did this
+public class Lock{}

src/JasperFx.CodeGeneration/Model/Variable.cs

@@ -12,6 +12,9 @@ namespace JasperFx.CodeGeneration.Model;
 
 public class Variable
 {
+    private static readonly string[] _reservedNames = new string[]
+        { "lock", "switch", "case", "if", "base", "catch", "class", "continue", "default" };
+
     private Frame? _frame;
 
     public Variable(Type variableType) : this(variableType, DefaultArgName(variableType))
@@ -85,6 +88,11 @@ public static Variable For<T>(string? variableName = null)
 
     public static string SanitizeVariableName(string variableName)
     {
+        if (_reservedNames.Contains(variableName))
+        {
+            return "@" + variableName;
+        }
+
         return variableName.Replace('<', '_').Replace('>', '_');
     }