snapshot of https://github.com/zulip/zulip.git @ 48c69911c7dd4e03b20552eb3bd77ad8151c1357 (2026-09-15)

zerver/lib/mdiff.py

@@ -0,0 +1,19 @@
+import logging
+import os
+import subprocess
+
+
+class DiffError(Exception):
+    pass
+
+
+def diff_strings(output: str, expected_output: str) -> str:
+    mdiff_path = "web/tests/lib/mdiff.cjs"
+    if not os.path.isfile(mdiff_path):  # nocoverage
+        msg = "Cannot find mdiff for Markdown diff rendering"
+        logging.error(msg)
+        raise DiffError(msg)
+
+    command = ["node", mdiff_path, output, expected_output]
+    diff = subprocess.check_output(command, text=True)
+    return diff