Avoid evaluating properties just for the api type, improves #1933

jedi/inference/compiled/mixed.py

@@ -142,9 +142,9 @@ class MixedObjectFilter(compiled.CompiledValueFilter):
         super().__init__(inference_state, compiled_value)
         self._tree_value = tree_value
 
-    def _create_name(self, name):
+    def _create_name(self, *args, **kwargs):
         return MixedName(
-            super()._create_name(name),
+            super()._create_name(*args, **kwargs),
             self._tree_value,
         )
 

jedi/inference/compiled/value.py

@@ -311,11 +311,12 @@ class CompiledModule(CompiledValue):
 
 
 class CompiledName(AbstractNameDefinition):
-    def __init__(self, inference_state, parent_value, name):
+    def __init__(self, inference_state, parent_value, name, is_descriptor):
         self._inference_state = inference_state
         self.parent_context = parent_value.as_context()
         self._parent_value = parent_value
         self.string_name = name
+        self.is_descriptor = is_descriptor
 
     def py__doc__(self):
         return self.infer_compiled_value().py__doc__()
@@ -342,6 +343,11 @@ class CompiledName(AbstractNameDefinition):
 
     @property
     def api_type(self):
+        if self.is_descriptor:
+            # In case of properties we want to avoid executions as much as
+            # possible. Since the api_type can be wrong for other reasons
+            # anyway, we just return instance here.
+            return "instance"
         return self.infer_compiled_value().api_type
 
     def infer(self):
@@ -456,14 +462,14 @@ class CompiledValueFilter(AbstractFilter):
 
         if self.is_instance and not in_dir_callback(name):
             return []
-        return [self._get_cached_name(name)]
+        return [self._get_cached_name(name, is_descriptor=is_descriptor)]
 
     @memoize_method
-    def _get_cached_name(self, name, is_empty=False):
+    def _get_cached_name(self, name, is_empty=False, *, is_descriptor=False):
         if is_empty:
             return EmptyCompiledName(self._inference_state, name)
         else:
-            return self._create_name(name)
+            return self._create_name(name, is_descriptor=is_descriptor)
 
     def values(self):
         from jedi.inference.compiled import builtin_from_name
@@ -487,11 +493,12 @@ class CompiledValueFilter(AbstractFilter):
                 names += filter.values()
         return names
 
-    def _create_name(self, name):
+    def _create_name(self, name, is_descriptor):
         return CompiledName(
             self._inference_state,
             self.compiled_value,
-            name
+            name,
+            is_descriptor,
         )
 
     def __repr__(self):

test/test_api/test_interpreter.py

@@ -102,11 +102,13 @@ def test_side_effect_completion():
     assert foo.name == 'foo'
 
 
-def _assert_interpreter_complete(source, namespace, completions,
+def _assert_interpreter_complete(source, namespace, completions, *, check_type=False, **kwds):
-                                 **kwds):
     script = jedi.Interpreter(source, [namespace], **kwds)
     cs = script.complete()
     actual = [c.name for c in cs]
+    if check_type:
+        for c in cs:
+            c.type
     assert sorted(actual) == sorted(completions)
 
 
@@ -757,3 +759,23 @@ def test_keyword_param_completion(code, expected):
     import random
     completions = jedi.Interpreter(code, [locals()]).complete()
     assert expected == [c.name for c in completions if c.name.endswith('=')]
+
+
+@pytest.mark.parametrize('class_is_findable', [False, True])
+def test_avoid_descriptor_executions_if_not_necessary(class_is_findable):
+    counter = 0
+    class AvoidDescriptor(object):
+        @property
+        def prop(self):
+            nonlocal counter
+            counter += 1
+            return self
+
+    if not class_is_findable:
+        AvoidDescriptor.__name__ = "something_somewhere"
+    namespace = {'b': AvoidDescriptor()}
+    expected = ['prop']
+    _assert_interpreter_complete('b.pro', namespace, expected, check_type=True)
+    assert counter == 0
+    _assert_interpreter_complete('b.prop.pro', namespace, expected, check_type=True)
+    assert counter == 1