Make it possible to access properties again

This time we catch all exceptions and try to avoid issues for the user.

This is only happening when working with an Interpreter. I don't feel this is
necessary otherwise.

See #1299

CHANGELOG.rst

@@ -11,6 +11,8 @@ Changelog
 - ``*args``/``**kwargs`` resolving. If possible Jedi replaces the parameters
   with the actual alternatives.
 - Better support for enums/dataclasses
+- When using Interpreter, properties are now executed, since a lot of people
+  have complained about this. Discussion in #1299.
 
 New APIs:
 

jedi/api/__init__.py

@@ -436,6 +436,7 @@ class Interpreter(Script):
     >>> print(script.completions()[0].name)
     upper
     """
+    _allow_descriptor_getattr_default = True
 
     def __init__(self, source, namespaces, **kwds):
         """
@@ -466,6 +467,7 @@ def __init__(self, source, namespaces, **kwds):
         super(Interpreter, self).__init__(source, environment=environment,
                                           _project=Project(os.getcwd()), **kwds)
         self.namespaces = namespaces
+        self._evaluator.allow_descriptor_getattr = self._allow_descriptor_getattr_default
 
     def _get_module(self):
         return interpreter.MixedModuleContext(

jedi/evaluate/__init__.py

@@ -106,6 +106,7 @@ def __init__(self, project, environment=None, script_path=None):
         self.is_analysis = False
         self.project = project
         self.access_cache = {}
+        self.allow_descriptor_getattr = False
 
         self.reset_recursion_limitations()
         self.allow_different_encoding = True

jedi/evaluate/compiled/access.py

@@ -340,12 +340,16 @@ def is_allowed_getattr(self, name):
     def getattr_paths(self, name, default=_sentinel):
         try:
             return_obj = getattr(self._obj, name)
-        except AttributeError:
-            # Happens e.g. in properties of
-            # PyQt4.QtGui.QStyleOptionComboBox.currentText
-            # -> just set it to None
+        except Exception as e:
             if default is _sentinel:
-                raise
+                if isinstance(e, AttributeError):
+                    # Happens e.g. in properties of
+                    # PyQt4.QtGui.QStyleOptionComboBox.currentText
+                    # -> just set it to None
+                    raise
+                # Just in case anything happens, return an AttributeError. It
+                # should not crash.
+                raise AttributeError
             return_obj = default
         access = self._create_access(return_obj)
         if inspect.ismodule(return_obj):

jedi/evaluate/compiled/context.py

@@ -399,7 +399,7 @@ def _get(self, name, allowed_getattr_callback, dir_callback, check_has_attribute
         # Always use unicode objects in Python 2 from here.
         name = force_unicode(name)
 
-        if is_descriptor or not has_attribute:
+        if (is_descriptor and not self._evaluator.allow_descriptor_getattr) or not has_attribute:
             return [self._get_cached_name(name, is_empty=True)]
 
         if self.is_instance and name not in dir_callback():

test/test_api/test_interpreter.py

@@ -7,7 +7,7 @@
 
 import jedi
 from jedi._compatibility import is_py3, py_version
-from jedi.evaluate.compiled import mixed
+from jedi.evaluate.compiled import mixed, context
 from importlib import import_module
 
 if py_version > 30:
@@ -197,7 +197,13 @@ def __getitem__(self, index):
     _assert_interpreter_complete('foo["asdf"].upper', locals(), ['upper'])
 
 
-def test_property_error_oldstyle():
+@pytest.fixture(params=[False, True])
+def allow_descriptor_access_or_not(request, monkeypatch):
+    monkeypatch.setattr(jedi.Interpreter, '_allow_descriptor_getattr_default', request.param)
+    return request.param
+
+
+def test_property_error_oldstyle(allow_descriptor_access_or_not):
     lst = []
     class Foo3:
         @property
@@ -209,11 +215,14 @@ def bar(self):
     _assert_interpreter_complete('foo.bar', locals(), ['bar'])
     _assert_interpreter_complete('foo.bar.baz', locals(), [])
 
-    # There should not be side effects
-    assert lst == []
+    if allow_descriptor_access_or_not:
+        assert lst == [1, 1]
+    else:
+        # There should not be side effects
+        assert lst == []
 
 
-def test_property_error_newstyle():
+def test_property_error_newstyle(allow_descriptor_access_or_not):
     lst = []
     class Foo3(object):
         @property
@@ -225,8 +234,22 @@ def bar(self):
     _assert_interpreter_complete('foo.bar', locals(), ['bar'])
     _assert_interpreter_complete('foo.bar.baz', locals(), [])
 
-    # There should not be side effects
-    assert lst == []
+    if allow_descriptor_access_or_not:
+        assert lst == [1, 1]
+    else:
+        # There should not be side effects
+        assert lst == []
+
+
+def test_property_content():
+    class Foo3(object):
+        @property
+        def bar(self):
+            return 1
+
+    foo = Foo3()
+    def_, = jedi.Interpreter('foo.bar', [locals()]).goto_definitions()
+    assert def_.name == 'int'
 
 
 @pytest.mark.skipif(sys.version_info[0] == 2, reason="Ignore Python 2, because EOL")