Make sure goto definitions works on with, fixes #1280

jedi/inference/__init__.py

@@ -76,7 +76,7 @@ from jedi.inference.base_value import ContextualizedNode, \
     ValueSet, iterate_values
 from jedi.inference.value import ClassValue, FunctionValue
 from jedi.inference.syntax_tree import infer_expr_stmt, \
-    check_tuple_assignments
+    check_tuple_assignments, tree_name_to_values
 from jedi.inference.imports import follow_error_node_imports_if_possible
 from jedi.plugins import plugin_manager
 
@@ -170,6 +170,8 @@ class InferenceState(object):
                 return check_tuple_assignments(n, for_types)
             if type_ in ('import_from', 'import_name'):
                 return imports.infer_import(context, name)
+            if type_ == 'with_stmt':
+                return tree_name_to_values(self, context, name)
         else:
             result = follow_error_node_imports_if_possible(context, name)
             if result is not None:

test/completion/basic.py

@@ -341,3 +341,19 @@ with open('') as f1, open('') as f2:
     f1.closed
     #? ['closed']
     f2.closed
+
+
+class Foo():
+    def __enter__(self):
+        return ''
+
+#? 14 str()
+with Foo() as f3:
+    #? str()
+    f3
+#! 14 ['with Foo() as f3: f3']
+with Foo() as f3:
+    f3
+#? 6 Foo
+with Foo() as f3:
+    f3

test/static_analysis/with_.py

@@ -0,0 +1,2 @@
+with open() as fin:
+    fin.read()