fix(exceptions): count duplicate-validator errors in ErrorTree

bugfix-mission · bugfix-mission · commit e66396467286 · 2026-04-23T15:56:48.000+08:00
ErrorTree.total_errors used len(self.errors), but self.errors is a
dict keyed by validator keyword, so multiple errors at the same path
sharing a validator (e.g. several 'type' failures) were collapsed and
undercounted. Track every error in an internal list and use its
length for total_errors.
diff --git a/jsonschema/exceptions.py b/jsonschema/exceptions.py
@@ -321,13 +321,15 @@ class ErrorTree:
 
     def __init__(self, errors: Iterable[ValidationError] = ()):
         self.errors: MutableMapping[str, ValidationError] = {}
+        self._all_errors: list[ValidationError] = []
         self._contents: Mapping[str, ErrorTree] = defaultdict(self.__class__)
 
         for error in errors:
             container = self
             for element in error.path:
                 container = container[element]
             container.errors[error.validator] = error
+            container._all_errors.append(error)
 
             container._instance = error.instance
 
@@ -390,7 +392,7 @@ def total_errors(self):
         The total number of errors in the entire tree, including children.
         """
         child_errors = sum(len(tree) for _, tree in self._contents.items())
-        return len(self.errors) + child_errors
+        return len(self._all_errors) + child_errors
 
 
 def by_relevance(weak=WEAK_MATCHES, strong=STRONG_MATCHES):
diff --git a/jsonschema/tests/test_exceptions.py b/jsonschema/tests/test_exceptions.py
@@ -394,6 +394,17 @@ def test_it_knows_how_many_total_errors_it_contains(self):
         tree = exceptions.ErrorTree(errors)
         self.assertEqual(tree.total_errors, 8)
 
+    def test_total_errors_counts_duplicate_validators(self):
+        # Regression test for #442: multiple errors at the same path
+        # sharing the same validator keyword should all be counted.
+        errors = [
+            exceptions.ValidationError("first", validator="type"),
+            exceptions.ValidationError("second", validator="type"),
+            exceptions.ValidationError("third", validator="type"),
+        ]
+        tree = exceptions.ErrorTree(errors)
+        self.assertEqual(tree.total_errors, 3)
+
     def test_it_contains_an_item_if_the_item_had_an_error(self):
         errors = [exceptions.ValidationError("a message", path=["bar"])]
         tree = exceptions.ErrorTree(errors)
