Terminate strings at NUL when recording states and events (#86687)

tests/helpers/test_json.py

@@ -10,6 +10,7 @@ from homeassistant import core
 from homeassistant.helpers.json import (
     ExtendedJSONEncoder,
     JSONEncoder,
+    json_bytes_strip_null,
     json_dumps,
     json_dumps_sorted,
 )
@@ -118,3 +119,19 @@ def test_json_dumps_rgb_color_subclass():
     rgb = RGBColor(4, 2, 1)
 
     assert json_dumps(rgb) == "[4,2,1]"
+
+
+def test_json_bytes_strip_null():
+    """Test stripping nul from strings."""
+
+    assert json_bytes_strip_null("\0") == b'""'
+    assert json_bytes_strip_null("silly\0stuff") == b'"silly"'
+    assert json_bytes_strip_null(["one", "two\0", "three"]) == b'["one","two","three"]'
+    assert (
+        json_bytes_strip_null({"k1": "one", "k2": "two\0", "k3": "three"})
+        == b'{"k1":"one","k2":"two","k3":"three"}'
+    )
+    assert (
+        json_bytes_strip_null([[{"k1": {"k2": ["silly\0stuff"]}}]])
+        == b'[[{"k1":{"k2":["silly"]}}]]'
+    )