PR number parsing fix

Author: banstack

reviewbot/utils.py

@@ -2,12 +2,18 @@
 import requests
 
 def get_diff():
-    # GitHub repo info and PR number are available in GitHub Actions env
     repo = os.environ.get("GITHUB_REPOSITORY")  # e.g. "owner/repo"
-    pr_number = os.environ.get("GITHUB_REF").split("/")[-1]  # e.g. "42"
+    ref = os.environ.get("GITHUB_REF")          # e.g. "refs/pull/123/merge"
 
-    if not repo or not pr_number:
-        raise Exception("Missing GitHub repository or PR number environment variables.")
+    if not repo or not ref:
+        raise Exception("Missing GitHub repository or ref environment variables.")
+
+    # Extract PR number safely:
+    parts = ref.split("/")
+    if len(parts) >= 3 and parts[-3] == "pull":
+        pr_number = parts[-2]
+    else:
+        raise Exception(f"Unexpected GITHUB_REF format: {ref}")
 
     token = os.environ.get("GITHUB_TOKEN")
     if not token:
@@ -21,8 +27,6 @@ def get_diff():
     url = f"https://api.github.com/repos/{repo}/pulls/{pr_number}/files"
 
     diffs = []
-
-    # Pagination handling in case there are many files
     page = 1
     while True:
         response = requests.get(url, headers=headers, params={"page": page, "per_page": 100})
@@ -39,4 +43,3 @@ def get_diff():
         page += 1
 
     return "\n".join(diffs)
-