Fix map no iterables (#8478)

william-goode · web-flow · commit e8431490e72b · 2026-08-11T21:16:10.000+09:00
* map: raise TypeError when called with no iterables

Assisted-by: Claude Code:claude-fable-5

* add test for map with no iterables

Assisted-by: Claude Code:claude-fable-5

* removed expectedFailures

* removed test for map constructed with no iterables - covered by existing in test_itertools
diff --git a/Lib/test/test_itertools.py b/Lib/test/test_itertools.py
@@ -1136,7 +1136,6 @@ def test_repeat_with_negative_times(self):
         self.assertEqual(repr(repeat('a', times=-1)), "repeat('a', 0)")
         self.assertEqual(repr(repeat('a', times=-2)), "repeat('a', 0)")
 
-    @unittest.expectedFailure  # TODO: RUSTPYTHON
     def test_map(self):
         self.assertEqual(list(map(operator.pow, range(3), range(1,7))),
                          [0**1, 1**2, 2**3])
diff --git a/crates/vm/src/builtins/map.rs b/crates/vm/src/builtins/map.rs
@@ -37,9 +37,12 @@ impl Constructor for PyMap {
     fn py_new(
         _cls: &Py<PyType>,
         (mapper, iterators, args): Self::Args,
-        _vm: &VirtualMachine,
+        vm: &VirtualMachine,
     ) -> PyResult<Self> {
         let iterators = iterators.into_vec();
+        if iterators.is_empty() {
+            return Err(vm.new_type_error("map() must have at least two arguments."));
+        }
         let strict = Radium::new(args.strict.unwrap_or(false));
         Ok(Self {
             mapper,
