several updates to functionality

tests/test_html_injection.py

@@ -0,0 +1,25 @@
+import unittest
+
+from generator import inject_outlook_hacks
+
+
+class HtmlInjectionTest(unittest.TestCase):
+    def test_html_injection_adds_folded_alt_desc(self) -> None:
+        ical_text = "\n".join(
+            [
+                "BEGIN:VCALENDAR",
+                "BEGIN:VEVENT",
+                "UID:abc123",
+                "END:VEVENT",
+                "END:VCALENDAR",
+            ]
+        )
+        long_html = "A" * 200
+        result = inject_outlook_hacks(ical_text, {"abc123": long_html})
+
+        self.assertIn("X-ALT-DESC;FMTTYPE=text/html:", result)
+        self.assertIn("X-MICROSOFT-CDO-BUSYSTATUS:BUSY", result)
+        self.assertIn("TRANSP:OPAQUE", result)
+        alt_index = result.find("X-ALT-DESC;FMTTYPE=text/html:")
+        self.assertNotEqual(alt_index, -1)
+        self.assertIn("\r\n ", result[alt_index : alt_index + 200])