Fix quoting long tuples

Author: ilevkivskyi

mypy/messages.py

@@ -2432,13 +2432,13 @@ def format_long_tuple_type(self, typ: TupleType) -> str:
         """Format very long tuple type using an ellipsis notation"""
         item_cnt = len(typ.items)
         if item_cnt > MAX_TUPLE_ITEMS:
-            return "tuple[{}, {}, ... <{} more items>]".format(
+            return '"tuple[{}, {}, ... <{} more items>]"'.format(
                 format_type_bare(typ.items[0], self.options),
                 format_type_bare(typ.items[1], self.options),
                 str(item_cnt - 2),
             )
         else:
-            return format_type_bare(typ, self.options)
+            return format_type(typ, self.options)
 
     def generate_incompatible_tuple_error(
         self,
@@ -2520,12 +2520,9 @@ def quote_type_string(type_string: str) -> str:
     if (
         type_string in ["Module", "overloaded function", "<deleted>"]
         or type_string.startswith("Module ")
-        or type_string.startswith(("<tuple: ", "<union: "))
-        and type_string.endswith(" items>")
         or type_string.endswith("?")
     ):
-        # Messages are easier to read if these aren't quoted.  We use a
-        # regex to match strings with variable contents.
+        # These messages are easier to read if these aren't quoted.
         return type_string
     return f'"{type_string}"'
 

test-data/unit/check-tuples.test

@@ -1612,7 +1612,7 @@ t4: Tuple[int, int, int, int, int, int, int, int, int, int, int, int] = (1, 2, 3
 t5: Tuple[int, int] = (1, 2, "s", 4)  # E: Incompatible types in assignment (expression has type "tuple[int, int, str, int]", variable has type "tuple[int, int]")
 
 # long initializer assignment with mismatched pairs
-t6: Tuple[int, int, int, int, int, int, int, int, int, int, int, int] = (1, 2, 3, 4, 5, 6, 7, 8, "str", "str", "str", "str", 1, 1, 1, 1, 1) # E: Incompatible types in assignment (expression has type tuple[int, int, ... <15 more items>], variable has type tuple[int, int, ... <10 more items>])
+t6: Tuple[int, int, int, int, int, int, int, int, int, int, int, int] = (1, 2, 3, 4, 5, 6, 7, 8, "str", "str", "str", "str", 1, 1, 1, 1, 1) # E: Incompatible types in assignment (expression has type "tuple[int, int, ... <15 more items>]", variable has type "tuple[int, int, ... <10 more items>]")
 
 [builtins fixtures/tuple.pyi]