Merge pull request #174 from netromdk/issue-159

Union types detection also considers attributes

tests/lang.py

@@ -1939,6 +1939,37 @@ class Bar: pass
     self.assertFalse(visitor.union_types())
 
     if current_version() >= (3, 10):
+      # Issue 159: Attributes can also be used for union types.
+      visitor = self.visit("""
+def function(argument: ipaddress.IPv4Interface | ipaddress.IPv6Interface):
+    if isinstance(argument, ipaddress.IPv4Address):
+        print("We got an IPv4")
+    elif isinstance(argument, ipaddress.IPv6Address):
+        print("We got an IPv6")
+    else:
+        print(f"We got type {type(argument)}")
+""")
+      self.assertTrue(visitor.union_types())
+      self.assertOnlyIn((3, 10), visitor.minimum_versions())
+      visitor = self.visit("""
+def function(argument: ipaddress.IPv4Interface | None):
+    pass
+""")
+      self.assertTrue(visitor.union_types())
+      self.assertOnlyIn((3, 10), visitor.minimum_versions())
+      visitor = self.visit("""
+def function(argument: None | ipaddress.IPv4Interface):
+    pass
+""")
+      self.assertTrue(visitor.union_types())
+      self.assertOnlyIn((3, 10), visitor.minimum_versions())
+      visitor = self.visit("""
+def function(argument: str | ipaddress.IPv4Interface):
+    pass
+""")
+      self.assertTrue(visitor.union_types())
+      self.assertOnlyIn((3, 10), visitor.minimum_versions())
+
       # Issue 109: When not evaluating annotations, returns annotations must not be visited.
       self.config.set_eval_annotations(False)
       visitor = self.visit("""

vermin/source_visitor.py

@@ -1386,10 +1386,16 @@ def has_du():
         has_du()
 
       def is_none_or_name(node):
-        return is_none_node(node) or \
-          (isinstance(node, ast.Name) and
-           ((node.id not in self.__name_res and node.id not in self.__user_defs) or
-            (node.id in self.__name_res_type)))
+        if is_none_node(node):
+          return True
+        name = None
+        if isinstance(node, ast.Name):
+          name = node.id
+        elif isinstance(node, ast.Attribute):
+          name = dotted_name(self.__get_attribute_name(node))
+        return name is not None and \
+          ((name not in self.__name_res and name not in self.__user_defs) or
+           (name in self.__name_res_type))
       if is_none_or_name(node.left) and is_none_or_name(node.right):
         self.__union_types = True
         self.__vvprint("union types as `X | Y`", line=node.lineno, versions=[None, (3, 10)],
@@ -1674,13 +1680,18 @@ def visit_AugAssign(self, node):
     # |=
     if isinstance(node.op, ast.BitOr):
       def is_union_type(node):
-        return isinstance(node, ast.Name) and \
-           ((node.id not in self.__name_res and node.id not in self.__user_defs) or
+        name = None
+        if isinstance(node, ast.Name):
+          name = node.id
+        elif isinstance(node, ast.Attribute):
+          name = dotted_name(self.__get_attribute_name(node))
+        return name is not None and \
+           ((name not in self.__name_res and name not in self.__user_defs) or
             # AugAssign: both variable names are the same so require two types.
-            (node.id in self.__name_res_type and len(self.__name_res_type[node.id]) > 1) or
+            (name in self.__name_res_type and len(self.__name_res_type[name]) > 1) or
             # Unless it's the target value, then require not name res, is user def and res type.
-            (node.id not in self.__name_res and node.id in self.__user_defs and \
-             node.id in self.__name_res_type))
+            (name not in self.__name_res and name in self.__user_defs and \
+             name in self.__name_res_type))
 
       # Example:
       # AugAssign(target=Name(id='d', ctx=Store()),