A first working iteration of dataclass signatures, fixes #1213

jedi/evaluate/names.py

@@ -168,14 +168,34 @@ class ParamNameInterface(object):
         raise NotImplementedError
 
 
-class ParamName(ParamNameInterface, AbstractTreeName):
-    def __init__(self, parent_context, tree_name):
-        self.parent_context = parent_context
-        self.tree_name = tree_name
+class BaseTreeParamName(ParamNameInterface, AbstractTreeName):
+    def get_default_node(self):
+        return None
 
+    def get_annotation_node(self):
+        return None
+
+    def to_string(self):
+        output = self._kind_string() + self.string_name
+        annotation = self.get_annotation_node()
+        default = self.get_default_node()
+        if annotation is not None:
+            output += ': ' + annotation.get_code(include_prefix=False)
+        if default is not None:
+            output += '=' + default.get_code(include_prefix=False)
+        return output
+
+
+class ParamName(BaseTreeParamName):
     def _get_param_node(self):
         return search_ancestor(self.tree_name, 'param')
 
+    def get_annotation_node(self):
+        return self._get_param_node().annotation
+
+    def get_default_node(self):
+        return self._get_param_node().default
+
     @property
     def string_name(self):
         name = self.tree_name.value
@@ -213,15 +233,6 @@ class ParamName(ParamNameInterface, AbstractTreeName):
                         param_appeared = True
         return Parameter.POSITIONAL_OR_KEYWORD
 
-    def to_string(self):
-        output = self._kind_string() + self.string_name
-        param_node = self._get_param_node()
-        if param_node.annotation is not None:
-            output += ': ' + param_node.annotation.get_code(include_prefix=False)
-        if param_node.default is not None:
-            output += '=' + param_node.default.get_code(include_prefix=False)
-        return output
-
     def infer(self):
         return self.get_param().infer()