PyObject.AsManagedObject gives a better error message

tminka · lostmsu · commit 107c8b99cd5a · 2021-01-04T16:18:16.000-08:00
DelegateManager.TrueDispatch gives a better error message
diff --git a/src/embed_tests/TestPyObject.cs b/src/embed_tests/TestPyObject.cs
@@ -59,9 +59,17 @@ def add(self, x, y):
         }
 
         [Test]
-        public void InvokeNull() {
+        public void InvokeNull()
+        {
             var list = PythonEngine.Eval("list");
             Assert.Throws<ArgumentNullException>(() => list.Invoke(new PyObject[] {null}));
         }
+
+        [Test]
+        public void AsManagedObjectInvalidCast()
+        {
+            var list = PythonEngine.Eval("list");
+            Assert.Throws<InvalidCastException>(() => list.AsManagedObject(typeof(int)));
+        }
     }
 }
diff --git a/src/runtime/delegatemanager.cs b/src/runtime/delegatemanager.cs
@@ -221,19 +221,17 @@ public void Dispose()
         public object Dispatch(ArrayList args)
         {
             IntPtr gs = PythonEngine.AcquireLock();
-            object ob = null;
+            object ob;
 
             try
             {
                 ob = TrueDispatch(args);
             }
-            catch (Exception e)
+            finally
             {
                 PythonEngine.ReleaseLock(gs);
-                throw e;
             }
 
-            PythonEngine.ReleaseLock(gs);
             return ob;
         }
 
@@ -266,27 +264,15 @@ public object TrueDispatch(ArrayList args)
                 return null;
             }
 
-            object result = null;
-            if (!Converter.ToManaged(op, rtype, out result, false))
+            object result;
+            if (!Converter.ToManaged(op, rtype, out result, true))
             {
                 Runtime.XDecref(op);
-                throw new ConversionException($"could not convert Python result to {rtype}");
+                throw new PythonException();
             }
 
             Runtime.XDecref(op);
             return result;
         }
     }
-
-
-    public class ConversionException : Exception
-    {
-        public ConversionException()
-        {
-        }
-
-        public ConversionException(string msg) : base(msg)
-        {
-        }
-    }
 }
diff --git a/src/runtime/pyobject.cs b/src/runtime/pyobject.cs
@@ -134,9 +134,9 @@ public static PyObject FromManagedObject(object ob)
         public object AsManagedObject(Type t)
         {
             object result;
-            if (!Converter.ToManaged(obj, t, out result, false))
+            if (!Converter.ToManaged(obj, t, out result, true))
             {
-                throw new InvalidCastException("cannot convert object to target type");
+                throw new InvalidCastException("cannot convert object to target type", new PythonException());
             }
             return result;
         }
@@ -154,12 +154,7 @@ public T As<T>()
             {
                 return (T)(this as object);
             }
-            object result;
-            if (!Converter.ToManaged(obj, typeof(T), out result, false))
-            {
-                throw new InvalidCastException("cannot convert object to target type");
-            }
-            return (T)result;
+            return (T)AsManagedObject(typeof(T));
         }
 
 
diff --git a/src/tests/test_delegate.py b/src/tests/test_delegate.py
@@ -1,5 +1,4 @@
 # -*- coding: utf-8 -*-
-# TODO: Add test for ObjectDelegate
 
 """Test CLR delegate support."""
 
@@ -257,6 +256,26 @@ def always_so_negative():
     assert not d()
     assert not ob.CallBoolDelegate(d)
 
+def test_object_delegate():
+    """Test object delegate."""
+    from Python.Test import ObjectDelegate
+
+    def create_object():
+        return DelegateTest()
+
+    d = ObjectDelegate(create_object)
+    ob = DelegateTest()
+    ob.CallObjectDelegate(d)
+
+def test_invalid_object_delegate():
+    """Test invalid object delegate with mismatched return type."""
+    from Python.Test import ObjectDelegate
+
+    d = ObjectDelegate(hello_func)
+    ob = DelegateTest()
+    with pytest.raises(TypeError):
+        ob.CallObjectDelegate(d)
+
     # test async delegates
 
     # test multicast delegates

Original file line number	Diff line number	Diff line change
`@@ -59,9 +59,17 @@ def add(self, x, y):`
`59`	`59`	`}`
`60`	`60`
`61`	`61`	`[Test]`
`62`		`- public void InvokeNull() {`
	`62`	`+ public void InvokeNull()`
	`63`	`+ {`
`63`	`64`	`var list = PythonEngine.Eval("list");`
`64`	`65`	`Assert.Throws<ArgumentNullException>(() => list.Invoke(new PyObject[] {null}));`
`65`	`66`	`}`
	`67`	`+`
	`68`	`+ [Test]`
	`69`	`+ public void AsManagedObjectInvalidCast()`
	`70`	`+ {`
	`71`	`+ var list = PythonEngine.Eval("list");`
	`72`	`+ Assert.Throws<InvalidCastException>(() => list.AsManagedObject(typeof(int)));`
	`73`	`+ }`
`66`	`74`	`}`
`67`	`75`	`}`
Original file line number	Diff line number	Diff line change
`@@ -221,19 +221,17 @@ public void Dispose()`
`221`	`221`	`public object Dispatch(ArrayList args)`
`222`	`222`	`{`
`223`	`223`	`IntPtr gs = PythonEngine.AcquireLock();`
`224`		`- object ob = null;`
	`224`	`+ object ob;`
`225`	`225`
`226`	`226`	`try`
`227`	`227`	`{`
`228`	`228`	`ob = TrueDispatch(args);`
`229`	`229`	`}`
`230`		`- catch (Exception e)`
	`230`	`+ finally`
`231`	`231`	`{`
`232`	`232`	`PythonEngine.ReleaseLock(gs);`
`233`		`- throw e;`
`234`	`233`	`}`
`235`	`234`
`236`		`- PythonEngine.ReleaseLock(gs);`
`237`	`235`	`return ob;`
`238`	`236`	`}`
`239`	`237`
`@@ -266,27 +264,15 @@ public object TrueDispatch(ArrayList args)`
`266`	`264`	`return null;`
`267`	`265`	`}`
`268`	`266`
`269`		`- object result = null;`
`270`		`- if (!Converter.ToManaged(op, rtype, out result, false))`
	`267`	`+ object result;`
	`268`	`+ if (!Converter.ToManaged(op, rtype, out result, true))`
`271`	`269`	`{`
`272`	`270`	`Runtime.XDecref(op);`
`273`		`- throw new ConversionException($"could not convert Python result to {rtype}");`
	`271`	`+ throw new PythonException();`
`274`	`272`	`}`
`275`	`273`
`276`	`274`	`Runtime.XDecref(op);`
`277`	`275`	`return result;`
`278`	`276`	`}`
`279`	`277`	`}`
`280`		`-`
`281`		`-`
`282`		`- public class ConversionException : Exception`
`283`		`- {`
`284`		`- public ConversionException()`
`285`		`- {`
`286`		`- }`
`287`		`-`
`288`		`- public ConversionException(string msg) : base(msg)`
`289`		`- {`
`290`		`- }`
`291`		`- }`
`292`	`278`	`}`
Original file line number	Diff line number	Diff line change
`@@ -134,9 +134,9 @@ public static PyObject FromManagedObject(object ob)`
`134`	`134`	`public object AsManagedObject(Type t)`
`135`	`135`	`{`
`136`	`136`	`object result;`
`137`		`- if (!Converter.ToManaged(obj, t, out result, false))`
	`137`	`+ if (!Converter.ToManaged(obj, t, out result, true))`
`138`	`138`	`{`
`139`		`- throw new InvalidCastException("cannot convert object to target type");`
	`139`	`+ throw new InvalidCastException("cannot convert object to target type", new PythonException());`
`140`	`140`	`}`
`141`	`141`	`return result;`
`142`	`142`	`}`
`@@ -154,12 +154,7 @@ public T As<T>()`
`154`	`154`	`{`
`155`	`155`	`return (T)(this as object);`
`156`	`156`	`}`
`157`		`- object result;`
`158`		`- if (!Converter.ToManaged(obj, typeof(T), out result, false))`
`159`		`- {`
`160`		`- throw new InvalidCastException("cannot convert object to target type");`
`161`		`- }`
`162`		`- return (T)result;`
	`157`	`+ return (T)AsManagedObject(typeof(T));`
`163`	`158`	`}`
`164`	`159`
`165`	`160`