Fix best_match's type matching when it's an array.

Closes: #973

CHANGELOG.rst

@@ -1,3 +1,9 @@
+v4.7.2
+------
+
+* Also have ``best_match`` handle cases where the ``type`` validator is an
+  array.
+
 v4.7.1
 ------
 

jsonschema/exceptions.py

@@ -143,11 +143,17 @@ def _contents(self):
 
     def _matches_type(self):
         try:
-            expected_type = self.schema["type"]
+            expected = self.schema["type"]
         except (KeyError, TypeError):
             return False
-        else:
-            return self._type_checker.is_type(self.instance, expected_type)
+
+        if isinstance(expected, str):
+            return self._type_checker.is_type(self.instance, expected)
+
+        return any(
+            self._type_checker.is_type(self.instance, expected_type)
+            for expected_type in expected
+        )
 
 
 class ValidationError(_Error):

jsonschema/tests/test_exceptions.py

@@ -158,6 +158,33 @@ def test_it_prioritizes_matching_types(self):
         best = self.best_match_of(instance={"foo": "bar"}, schema=reordered)
         self.assertEqual(best.validator, "minLength")
 
+    def test_it_prioritizes_matching_union_types(self):
+        schema = {
+            "properties": {
+                "foo": {
+                    "anyOf": [
+                        {"type": ["array", "object"], "minItems": 2},
+                        {"type": ["integer", "string"], "minLength": 10},
+                    ],
+                },
+            },
+        }
+        best = self.best_match_of(instance={"foo": "bar"}, schema=schema)
+        self.assertEqual(best.validator, "minLength")
+
+        reordered = {
+            "properties": {
+                "foo": {
+                    "anyOf": [
+                        {"type": "string", "minLength": 10},
+                        {"type": "array", "minItems": 2},
+                    ],
+                },
+            },
+        }
+        best = self.best_match_of(instance={"foo": "bar"}, schema=reordered)
+        self.assertEqual(best.validator, "minLength")
+
     def test_boolean_schemas(self):
         schema = {"properties": {"foo": False}}
         best = self.best_match_of(instance={"foo": "bar"}, schema=schema)