diff --git a/tests/test_mapping.py b/tests/test_mapping.py
new file mode 100644
index 0000000..e05b798
--- /dev/null
+++ b/tests/test_mapping.py
@@ -0,0 +1,38 @@
+from hooked_containers.mapping import HookedMapping
+
+
+class TestHookedMapping:
+    class TestConstruction:
+        def test_empty(self):
+            m = HookedMapping({})
+            assert m._data == {}
+            assert dict(m) == {}
+
+        def test_with_existing(self):
+            existing = {"a": 1, "b": 2}
+            og_id = id(existing)
+            m = HookedMapping(existing)
+            assert id(m._data) == og_id
+            assert dict(m) == existing
+
+        def test_nesting(self):
+            existing = {"a": {"x": 1}, "b": {"y": 2}}
+            m = HookedMapping(existing)
+            assert dict(m) == existing
+            assert dict(m["a"]) == {"x": 1}
+            assert dict(m["b"]) == {"y": 2}
+
+    class TestMappingOps:
+        def test_setitem(self):
+            m = HookedMapping({})
+            m["a"] = 1
+            assert m._data == {"a": 1}
+
+        def test_getitem(self):
+            m = HookedMapping({"a": 1})
+            assert m["a"] == 1
+
+        def test_delitem(self):
+            m = HookedMapping({"a": 1})
+            del m["a"]
+            assert not m["a"]