Bug dynamic class throwing on hasattr (#96)

* Throw AttributeError in tp_getattro for dynamic classes

Python api documentation indicates it should throw AttributeError

* Bump version to 2.0.41

Author: jhonabreul

src/embed_tests/TestPropertyAccess.cs

@@ -1410,6 +1410,62 @@ def CallDynamicMethodCatchingExceptions(self, fixture, defaultValue):
             }
         }
 
+        public class ThrowingDynamicFixture : DynamicFixture
+        {
+            public override bool TryGetMember(GetMemberBinder binder, out object result)
+            {
+                if (!base.TryGetMember(binder, out result))
+                {
+                    throw new InvalidOperationException("Member not found");
+                }
+                return true;
+            }
+        }
+
+        [Test]
+        public void TestHasAttrShouldNotThrowIfAttributeIsNotPresentForDynamicClassObjects()
+        {
+            using var _ = Py.GIL();
+
+            dynamic module = PyModule.FromString("TestHasAttrShouldNotThrowIfAttributeIsNotPresentForDynamicClassObjects", @"
+from clr import AddReference
+AddReference(""Python.EmbeddingTest"")
+AddReference(""System"")
+
+from Python.EmbeddingTest import TestPropertyAccess
+
+class TestDynamicClass(TestPropertyAccess.ThrowingDynamicFixture):
+    def __init__(self):
+        self.test_attribute = 11;
+
+def has_attribute(obj, attribute):
+    return hasattr(obj, attribute)
+");
+
+            dynamic fixture = module.GetAttr("TestDynamicClass")();
+            dynamic hasAttribute = module.GetAttr("has_attribute");
+
+            var hasAttributeResult = false;
+            Assert.DoesNotThrow(() =>
+            {
+                hasAttributeResult = hasAttribute(fixture, "test_attribute");
+            });
+            Assert.IsTrue(hasAttributeResult);
+
+            var attribute = 0;
+            Assert.DoesNotThrow(() =>
+            {
+                attribute = fixture.test_attribute.As<int>();
+            });
+            Assert.AreEqual(11, attribute);
+
+            Assert.DoesNotThrow(() =>
+            {
+                hasAttributeResult = hasAttribute(fixture, "non_existent_attribute");
+            });
+            Assert.IsFalse(hasAttributeResult);
+        }
+
         public interface IModel
         {
             void InvokeModel();

src/perf_tests/Python.PerformanceTests.csproj

@@ -13,7 +13,7 @@
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
     </PackageReference>
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.*" />
-    <PackageReference Include="quantconnect.pythonnet" Version="2.0.40" GeneratePathProperty="true">
+    <PackageReference Include="quantconnect.pythonnet" Version="2.0.41" GeneratePathProperty="true">
       <IncludeAssets>compile</IncludeAssets>
     </PackageReference>
   </ItemGroup>
@@ -25,7 +25,7 @@
   </Target>
 
   <Target Name="CopyBaseline" AfterTargets="Build">
-    <Copy SourceFiles="$(NuGetPackageRoot)quantconnect.pythonnet\2.0.40\lib\net6.0\Python.Runtime.dll" DestinationFolder="$(OutDir)baseline" />
+    <Copy SourceFiles="$(NuGetPackageRoot)quantconnect.pythonnet\2.0.41\lib\net6.0\Python.Runtime.dll" DestinationFolder="$(OutDir)baseline" />
   </Target>
 
   <Target Name="CopyNewBuild" AfterTargets="Build">

src/runtime/Properties/AssemblyInfo.cs

@@ -4,5 +4,5 @@
 [assembly: InternalsVisibleTo("Python.EmbeddingTest, PublicKey=00240000048000009400000006020000002400005253413100040000110000005ffd8f49fb44ab0641b3fd8d55e749f716e6dd901032295db641eb98ee46063cbe0d4a1d121ef0bc2af95f8a7438d7a80a3531316e6b75c2dae92fb05a99f03bf7e0c03980e1c3cfb74ba690aca2f3339ef329313bcc5dccced125a4ffdc4531dcef914602cd5878dc5fbb4d4c73ddfbc133f840231343e013762884d6143189")]
 [assembly: InternalsVisibleTo("Python.Test, PublicKey=00240000048000009400000006020000002400005253413100040000110000005ffd8f49fb44ab0641b3fd8d55e749f716e6dd901032295db641eb98ee46063cbe0d4a1d121ef0bc2af95f8a7438d7a80a3531316e6b75c2dae92fb05a99f03bf7e0c03980e1c3cfb74ba690aca2f3339ef329313bcc5dccced125a4ffdc4531dcef914602cd5878dc5fbb4d4c73ddfbc133f840231343e013762884d6143189")]
 
-[assembly: AssemblyVersion("2.0.40")]
-[assembly: AssemblyFileVersion("2.0.40")]
+[assembly: AssemblyVersion("2.0.41")]
+[assembly: AssemblyFileVersion("2.0.41")]

src/runtime/Python.Runtime.csproj

@@ -5,7 +5,7 @@
     <RootNamespace>Python.Runtime</RootNamespace>
     <AssemblyName>Python.Runtime</AssemblyName>
     <PackageId>QuantConnect.pythonnet</PackageId>
-    <Version>2.0.40</Version>
+    <Version>2.0.41</Version>
     <GenerateAssemblyInfo>false</GenerateAssemblyInfo>
     <PackageLicenseFile>LICENSE</PackageLicenseFile>
     <RepositoryUrl>https://github.com/pythonnet/pythonnet</RepositoryUrl>

src/runtime/Types/DynamicClassObject.cs

@@ -88,7 +88,12 @@ public static NewReference tp_getattro(BorrowedReference ob, BorrowedReference k
                 catch (Exception exception)
                 {
                     Exceptions.Clear();
-                    Exceptions.SetError(exception);
+                    // tp_getattro should call PyObject_GenericGetAttr (which we already did)
+                    // which must throw AttributeError if the attribute is not found (see https://docs.python.org/3/c-api/object.html#c.PyObject_GenericGetAttr)
+                    // So if we are throwing anything, it must be AttributeError.
+                    // e.g hasattr uses this method to check if the attribute exists. If we throw anything other than AttributeError,
+                    // hasattr will throw instead of catching and returning False.
+                    Exceptions.SetError(Exceptions.AttributeError, exception.Message);
                 }
             }