Merge pull request #27 from cjwatson/fix-invalid-variable-name-message

Fix "Invalid variable name" error for base of path

CHANGES.rst

@@ -7,6 +7,9 @@
 
 - Add support for Python 3.9, 3.10.
 
+- Fix error message raised if the first element of a path expression is not
+  a valid name.
+
 
 5.1 (2020-07-06)
 ================

src/zope/tales/expressions.py

@@ -124,7 +124,7 @@ def __init__(self, path, traverser, engine):
         base = first[0]
         if base and not _valid_name(base):
             raise engine.getCompilerError()(
-                'Invalid variable name "%s"' % element)
+                'Invalid variable name "%s"' % base)
         self._base = base
         compiledpath[0] = first[1:]
         self._compiled_path = tuple(compiledpath)

src/zope/tales/tests/test_expressions.py

@@ -193,8 +193,13 @@ def testBadInitalDynamic(self):
 
     def test_dynamic_invalid_variable_name(self):
         from zope.tales.tales import CompilerError
-        with self.assertRaisesRegex(CompilerError, "Invalid variable name"):
+        with self.assertRaisesRegex(
+                CompilerError, 'Invalid variable name "123"'):
             self.engine.compile('path:a/?123')
+        # Deliberate typo for the TAL construct "structure ...".
+        with self.assertRaisesRegex(
+                CompilerError, 'Invalid variable name "structured a"'):
+            self.engine.compile('structured a/b')
 
     def testOldStyleClassIsCalled(self):
         class AnOldStyleClass: