Add extra tests for empty TypeVarTuples

Author: A5rocks

test-data/unit/check-generics.test

@@ -3624,9 +3624,31 @@ t2.foo = [1]  # E: Value of type variable "T" of "foo" of "Test" cannot be "int"
 [builtins fixtures/property.pyi]
 
 [case testMissingTypeArgsInApplication]
-x: list[()] = []  # E: "list" expects 1 type argument, but none given
+from typing import Generic
+from typing_extensions import Unpack, TypeVarTuple
+
+Ts = TypeVarTuple("Ts")
+
+class CanHaveZero(Generic[Unpack[Ts]]): ...
+
+ok1: CanHaveZero[()]
+ok2: tuple[()]
+
+bad1: list[()] = []  # E: "list" expects 1 type argument, but none given
+[builtins fixtures/tuple.pyi]
 
 [case testMissingTypeArgsInApplicationStrict]
 # flags: --strict
-x: list[()] = []  # E: "list" expects 1 type argument, but none given \
-                  # E: Missing type arguments for generic type "list"
+from typing import Generic
+from typing_extensions import Unpack, TypeVarTuple
+
+Ts = TypeVarTuple("Ts")
+
+class CanHaveZero(Generic[Unpack[Ts]]): ...
+
+ok1: CanHaveZero[()]
+ok2: tuple[()]
+
+bad1: list[()] = []  # E: "list" expects 1 type argument, but none given \
+                     # E: Missing type arguments for generic type "list"
+[builtins fixtures/tuple.pyi]