Don't include if in the schema_path of errors.

Closes: #696

This is definitely not the right general solution though.

That was obvious before given that $ref needed special casing,
but it's even more obvious now.

As-is, downstream implementers of new validator keywords have
no way to get this kind of behavior. It's additional complexity
that's been introduced in modern specs, but it seems likely
that a generic mechanism now needs adding for allowing keywords
to more cleanly ignore themselves in schema paths, or otherwise
do more complex manipulation of the schema path for an error.

Author: Julian

jsonschema/tests/test_validators.py

@@ -1062,7 +1062,7 @@ def test_if_then(self):
         self.assertEqual(error.message, "13 was expected")
         self.assertEqual(error.path, deque([]))
         self.assertEqual(error.json_path, '$')
-        self.assertEqual(error.schema_path, deque(["if", "then", "const"]))
+        self.assertEqual(error.schema_path, deque(["then", "const"]))
 
     def test_if_else(self):
         schema = {
@@ -1077,7 +1077,7 @@ def test_if_else(self):
         self.assertEqual(error.message, "13 was expected")
         self.assertEqual(error.path, deque([]))
         self.assertEqual(error.json_path, '$')
-        self.assertEqual(error.schema_path, deque(["if", "else", "const"]))
+        self.assertEqual(error.schema_path, deque(["else", "const"]))
 
     def test_boolean_schema_False(self):
         validator = validators.Draft7Validator(False)

jsonschema/validators.py

@@ -333,7 +333,7 @@ def iter_errors(self, instance, _schema=None):
                             instance=instance,
                             schema=_schema,
                         )
-                        if k != u"$ref":
+                        if k not in {u"if", u"$ref"}:
                             error.schema_path.appendleft(k)
                         yield error
             finally: