Ensure methods of Object are also available on interface objects (pythonnet#1284)

danabr · web-flow · commit 7870a9f09ac7 · 2020-11-17T15:33:59.000-08:00
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -32,6 +32,7 @@ details about the cause of the failure
 -    Indexers can now be used with interface objects
 -    Fixed a bug where indexers could not be used if they were inherited
 -    Made it possible to use `__len__` also on `ICollection<>` interface objects
+-    Made it possible to call `ToString`, `GetHashCode`, and `GetType` on inteface objects
 
 ### Removed
 
diff --git a/src/runtime/classmanager.cs b/src/runtime/classmanager.cs
@@ -341,6 +341,17 @@ private static ClassInfo GetClassInfo(Type type)
                         }
                     }
                 }
+
+                // All interface implementations inherit from Object,
+                // but GetMembers don't return them either.
+                var objFlags = BindingFlags.Public | BindingFlags.Instance;
+                foreach (var mi in typeof(object).GetMembers(objFlags))
+                {
+                    if (local[mi.Name] == null)
+                    {
+                        items.Add(mi);
+                    }
+                }
             }
 
             for (i = 0; i < items.Count; i++)
diff --git a/src/tests/test_interface.py b/src/tests/test_interface.py
@@ -136,3 +136,14 @@ def test_interface_collection_iteration():
     untyped_list.Add(elem)
     for e in untyped_list:
         assert type(e).__name__ == "int"
+
+
+def test_methods_of_Object_are_available():
+    """Test calling methods inherited from Object"""
+    import System
+    clrVal =  System.Int32(100)
+    i = System.IComparable(clrVal)
+    assert i.Equals(clrVal)
+    assert clrVal.GetHashCode() == i.GetHashCode()
+    assert clrVal.GetType() == i.GetType()
+    assert clrVal.ToString() == i.ToString()

Original file line number	Diff line number	Diff line change
`@@ -341,6 +341,17 @@ private static ClassInfo GetClassInfo(Type type)`
`341`	`341`	`}`
`342`	`342`	`}`
`343`	`343`	`}`
	`344`	`+`
	`345`	`+ // All interface implementations inherit from Object,`
	`346`	`+ // but GetMembers don't return them either.`
	`347`	`+ var objFlags = BindingFlags.Public \| BindingFlags.Instance;`
	`348`	`+ foreach (var mi in typeof(object).GetMembers(objFlags))`
	`349`	`+ {`
	`350`	`+ if (local[mi.Name] == null)`
	`351`	`+ {`
	`352`	`+ items.Add(mi);`
	`353`	`+ }`
	`354`	`+ }`
`344`	`355`	`}`
`345`	`356`
`346`	`357`	`for (i = 0; i < items.Count; i++)`