Fix cases where dicts are passed to dicts and generics were not properly applied

jedi/inference/arguments.py

@@ -4,6 +4,7 @@ from parso.python import tree
 
 from jedi._compatibility import zip_longest
 from jedi import debug
+from jedi.cache import memoize_method
 from jedi.inference.utils import PushBackIterator
 from jedi.inference import analysis
 from jedi.inference.lazy_value import LazyKnownValue, LazyKnownValues, \
@@ -158,6 +159,7 @@ class AbstractArguments(_AbstractArgumentsMixin):
 
 
 class AnonymousArguments(AbstractArguments):
+    @memoize_method
     def get_executed_param_names_and_issues(self, execution_context):
         from jedi.inference.dynamic_params import search_param_names
         return search_param_names(

jedi/inference/gradual/annotation.py

@@ -13,7 +13,7 @@ from jedi._compatibility import force_unicode, Parameter
 from jedi.inference.cache import inference_state_method_cache
 from jedi.inference.base_value import ValueSet, NO_VALUES
 from jedi.inference.gradual.typing import TypeVar, LazyGenericClass, \
-    AbstractAnnotatedClass
+    AbstractAnnotatedClass, TypingClassValueWithIndex
 from jedi.inference.gradual.typing import GenericClass
 from jedi.inference.helpers import is_string
 from jedi.inference.compiled import builtin_from_name
@@ -275,10 +275,11 @@ def infer_type_vars_for_execution(execution_context, annotation_dict):
 
 def _merge_type_var_dicts(base_dict, new_dict):
     for type_var_name, values in new_dict.items():
-        try:
-            base_dict[type_var_name] |= values
-        except KeyError:
-            base_dict[type_var_name] = values
+        if values:
+            try:
+                base_dict[type_var_name] |= values
+            except KeyError:
+                base_dict[type_var_name] = values
 
 
 def _infer_type_vars(annotation_value, value_set):

jedi/inference/value/function.py

@@ -285,7 +285,6 @@ class FunctionExecutionContext(ValueContext, TreeContextMixin):
                                              until_position=until_position,
                                              origin_scope=origin_scope)
 
-    @inference_state_method_cache()
     def get_executed_param_names_and_issues(self):
         return self.var_args.get_executed_param_names_and_issues(self)
 

jedi/inference/value/instance.py

@@ -195,6 +195,7 @@ class AbstractInstanceValue(Value):
                     name.tree_name.parent
                 )
                 bound_method = BoundMethod(self, function)
+
                 yield bound_method.as_context(self.var_args)
 
     @inference_state_method_cache()
@@ -288,22 +289,24 @@ class TreeInstance(AbstractInstanceValue):
         from jedi.inference.gradual.annotation import py__annotations__, \
             infer_type_vars_for_execution
 
-        for func in self._get_annotation_init_functions():
+        for signature in self.class_value.py__getattribute__('__init__').get_signatures():
             # Just take the first result, it should always be one, because we
             # control the typeshed code.
-            bound = BoundMethod(self, func)
-            execution = bound.as_context(self.var_args)
+            bound_method = BoundMethod(self, signature.value)
+            execution = bound_method.as_context(self.var_args)
             if not execution.matches_signature():
                 # First check if the signature even matches, if not we don't
                 # need to infer anything.
                 continue
 
             all_annotations = py__annotations__(execution.tree_node)
-            defined, = self.class_value.define_generics(
-                infer_type_vars_for_execution(execution, all_annotations),
-            )
-            debug.dbg('Inferred instance value as %s', defined, color='BLUE')
-            return defined
+            type_var_dict = infer_type_vars_for_execution(execution, all_annotations)
+            if type_var_dict:
+                defined, = self.class_value.define_generics(
+                    infer_type_vars_for_execution(execution, all_annotations),
+                )
+                debug.dbg('Inferred instance value as %s', defined, color='BLUE')
+                return defined
         return None
 
     def get_annotated_class_object(self):

test/completion/arrays.py

@@ -261,6 +261,9 @@ def y(a):
 #?
 y(**d)
 
+#? str()
+d['a']
+
 # problem with more complicated casts
 dic = {str(key): ''}
 #? str()