Basic support for TypeAlias, fixes #1969

jedi/inference/syntax_tree.py

@@ -703,9 +703,12 @@ def tree_name_to_values(inference_state, context, tree_name):
             if expr_stmt.type == "expr_stmt" and expr_stmt.children[1].type == "annassign":
                 correct_scope = parser_utils.get_parent_scope(name) == context.tree_node
                 ann_assign = expr_stmt.children[1]
-                if correct_scope:
+                first = ann_assign.children[1]
+                code = first.get_code()
+                if correct_scope and not (code.endswith(".TypeAlias")
+                                          or code.strip() == "TypeAlias"):
                     if (
-                        (ann_assign.children[1].type == 'name')
+                        (first.type == 'name')
                         and (ann_assign.children[1].value == tree_name.value)
                         and context.parent_context
                     ):

test/completion/pep0484_typing.py

@@ -587,3 +587,20 @@ b.add_x(2).add_y(5)
 b.add_x(2).add_not_implemented(5)
 #? Builder()
 b.add_x(2).add_not_implemented_typing_extensions(5)
+
+# -----------------
+# TypeAlias (see also #1969)
+# -----------------
+
+from typing import TypeAlias
+
+IntX: typing.TypeAlias = int
+IntY: TypeAlias = int
+
+#? int
+IntX
+def f(x: IntX, y: IntY):
+    #? int()
+    x
+    #? int()
+    y