Reject empty type and field names in namedutils

boltons/namedutils.py

@@ -160,10 +160,10 @@ def namedtuple(typename, field_names, verbose=False, rename=False):
                 field_names[index] = '_%d' % index
             seen.add(name)
     for name in [typename] + field_names:
-        if not all(c.isalnum() or c == '_' for c in name):
-            raise ValueError('Type names and field names can only contain '
-                             'alphanumeric characters and underscores: %r'
-                             % name)
+        if not name or not all(c.isalnum() or c == '_' for c in name):
+            raise ValueError('Type names and field names must be non-empty '
+                             'and can only contain alphanumeric characters '
+                             'and underscores: %r' % name)
         if _iskeyword(name):
             raise ValueError('Type names and field names cannot be a '
                              'keyword: %r' % name)
@@ -319,10 +319,10 @@ def namedlist(typename, field_names, verbose=False, rename=False):
                 field_names[index] = '_%d' % index
             seen.add(name)
     for name in [typename] + field_names:
-        if not all(c.isalnum() or c == '_' for c in name):
-            raise ValueError('Type names and field names can only contain '
-                             'alphanumeric characters and underscores: %r'
-                             % name)
+        if not name or not all(c.isalnum() or c == '_' for c in name):
+            raise ValueError('Type names and field names must be non-empty '
+                             'and can only contain alphanumeric characters '
+                             'and underscores: %r' % name)
         if _iskeyword(name):
             raise ValueError('Type names and field names cannot be a '
                              'keyword: %r' % name)

tests/test_namedutils.py

@@ -1,5 +1,7 @@
 from pickle import loads, dumps
 
+import pytest
+
 from boltons.namedutils import namedlist, namedtuple
 
 Point = namedtuple('Point', 'x, y', rename=True)
@@ -24,3 +26,29 @@ def test_namedlist_pickle():
 def test_namedtuple_pickle():
     p = Point(x=10, y=20)
     assert p == loads(dumps(p))
+
+
+@pytest.mark.parametrize("factory", [namedtuple, namedlist])
+def test_empty_field_name_raises_value_error(factory):
+    # `all()` is True for the empty string, so an empty name used to pass both
+    # ValueError checks and reach `name[0].isdigit()`, raising IndexError.
+    with pytest.raises(ValueError):
+        factory('Point', ['x', ''])
+
+
+@pytest.mark.parametrize("factory", [namedtuple, namedlist])
+def test_empty_type_name_raises_value_error(factory):
+    with pytest.raises(ValueError):
+        factory('', ['x', 'y'])
+
+
+@pytest.mark.parametrize("factory", [namedtuple, namedlist])
+def test_invalid_character_still_raises_value_error(factory):
+    with pytest.raises(ValueError):
+        factory('Point', ['x', 'y-z'])
+
+
+@pytest.mark.parametrize("factory", [namedtuple, namedlist])
+def test_valid_names_still_accepted(factory):
+    cls = factory('Point', ['x', 'y'])
+    assert cls(x=1, y=2).x == 1