From f8e1dd12f78d386ffa99e093c426d9ff4a94a9c0 Mon Sep 17 00:00:00 2001
From: Yngve Mardal Moe <yngve.m.moe@gmail.com>
Date: Mon, 17 Aug 2026 03:40:43 +0000
Subject: [PATCH] Implement __add__ for HtmlString

---
 python/stringalign/visualize.py           | 3 +++
 tests/visualize/HtmlString/test__add__.py | 5 +++++
 2 files changed, 8 insertions(+)
 create mode 100644 tests/visualize/HtmlString/test__add__.py

diff --git a/python/stringalign/visualize.py b/python/stringalign/visualize.py
index f212d9e..bce9e41 100644
--- a/python/stringalign/visualize.py
+++ b/python/stringalign/visualize.py
@@ -21,6 +21,9 @@ def __repr__(self) -> str:
     def _repr_html_(self) -> str:
         return self
 
+    def __add__(self, other: str) -> HtmlString:
+        return HtmlString(super().__add__(other))
+
 
 def compress_css(css: str) -> str:
     """Simple compression of css that turns all whitespace into a single space.
diff --git a/tests/visualize/HtmlString/test__add__.py b/tests/visualize/HtmlString/test__add__.py
new file mode 100644
index 0000000..33d9391
--- /dev/null
+++ b/tests/visualize/HtmlString/test__add__.py
@@ -0,0 +1,5 @@
+from stringalign.visualize import HtmlString
+
+
+def test_returns_htmlstring():
+    assert isinstance(HtmlString("a") + HtmlString("b"), HtmlString)