fix: getattr on an invalid field raises AttributeError (#73)

Fix for #31

Author: software-dov

packages/proto-plus/proto/message.py

@@ -504,10 +504,13 @@ def __getattr__(self, key):
             their Python equivalents. See the ``marshal`` module for
             more details.
         """
-        pb_type = self._meta.fields[key].pb_type
-        pb_value = getattr(self._pb, key)
-        marshal = self._meta.marshal
-        return marshal.to_python(pb_type, pb_value, absent=key not in self)
+        try:
+            pb_type = self._meta.fields[key].pb_type
+            pb_value = getattr(self._pb, key)
+            marshal = self._meta.marshal
+            return marshal.to_python(pb_type, pb_value, absent=key not in self)
+        except KeyError as ex:
+            raise AttributeError(str(ex))
 
     def __ne__(self, other):
         """Return True if the messages are unequal, False otherwise."""

packages/proto-plus/tests/test_message.py

@@ -207,3 +207,12 @@ class Foo(proto.Message):
     assert isinstance(Foo.pb(Foo()), Foo.pb())
     with pytest.raises(TypeError):
         Foo.pb(object())
+
+
+def test_invalid_field_access():
+    class Squid(proto.Message):
+        mass_kg = proto.Field(proto.INT32, number=1)
+
+    s = Squid()
+    with pytest.raises(AttributeError):
+        getattr(s, "shell")