1 files changed, 28 insertions, 0 deletions
diff --git a/_test/test_api_change.py b/_test/test_api_change.py
new file mode 100644
index 0000000..10997f4
--- /dev/null
+++ b/_test/test_api_change.py
@@ -0,0 +1,28 @@
+# coding: utf-8
+
+"""
+testing of anchors and the aliases referring to them
+"""
+
+import pytest
+from ruamel.yaml import YAML
+from ruamel.yaml.constructor import DuplicateKeyError
+
+
+class TestNewAPI:
+    def test_duplicate_keys_00(self):
+        from ruamel.yaml.constructor import DuplicateKeyError
+        yaml = YAML()
+        with pytest.raises(DuplicateKeyError):
+            yaml.load('{a: 1, a: 2}')
+
+    def test_duplicate_keys_01(self):
+        yaml = YAML(typ='safe', pure=True)
+        with pytest.raises(DuplicateKeyError):
+            yaml.load('{a: 1, a: 2}')
+
+    # @pytest.mark.xfail(strict=True)
+    def test_duplicate_keys_02(self):
+        yaml = YAML(typ='safe')
+        with pytest.raises(DuplicateKeyError):
+            yaml.load('{a: 1, a: 2}')