From a3cf05c4b3935cb2bfbfedd129bb6dd7690e8130 Mon Sep 17 00:00:00 2001
From: Joachim Jablon <joachim@botify.com>
Date: Tue, 26 Sep 2023 09:18:52 +0200
Subject: [PATCH] Add better error handling for wrong diff format

---
 coverage_comment/coverage.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/coverage_comment/coverage.py b/coverage_comment/coverage.py
index 87c4dca0..75c43bf9 100644
--- a/coverage_comment/coverage.py
+++ b/coverage_comment/coverage.py
@@ -288,7 +288,8 @@ def parse_diff_output(diff: str) -> dict[pathlib.Path, list[int]]:
             current_file = pathlib.Path(line.removeprefix(added_filename_prefix))
             continue
         if line.startswith("@@"):
-            assert current_file
+            if current_file is None:
+                raise ValueError(f"Unexpected diff output format: \n{diff}")
             lines = parse_line_number_diff_line(line)
             result.setdefault(current_file, []).extend(lines)
             continue