Add GitHub PR diff context to changelog (#94)

* Include GitHub PR diffs in changelog generation

* Add API version header to GitHub diff requests

Author: redreceipt

github.py

@@ -2,6 +2,7 @@
 from datetime import datetime, timedelta
 from functools import lru_cache
 from typing import Any, Dict, List
+import requests
 
 from dotenv import load_dotenv
 from gql import Client, gql
@@ -18,6 +19,14 @@
 )
 client = Client(transport=transport, fetch_schema_from_transport=True)
 
+# headers used for REST API requests
+rest_headers = {
+    "Authorization": f"bearer {token}",
+    "Accept": "application/vnd.github.v3.diff",
+    # Use the latest stable REST API version
+    "X-GitHub-Api-Version": "2022-11-28",
+}
+
 
 @lru_cache(maxsize=1)
 def get_repo_ids():
@@ -253,3 +262,11 @@ def get_prs_with_changes_requested_by_reviewer():
                 reviewer = review["author"]["login"]
                 cr_prs.setdefault(reviewer, []).append(pr)
     return cr_prs
+
+
+def get_pr_diff(owner: str, repo: str, number: int) -> str:
+    """Return the diff for a pull request."""
+    url = f"https://api.github.com/repos/{owner}/{repo}/pulls/{number}"
+    resp = requests.get(url, headers=rest_headers)
+    resp.raise_for_status()
+    return resp.text

jobs.py

@@ -4,6 +4,7 @@
 from datetime import datetime, timezone
 
 import requests
+import re
 import schedule
 from dotenv import load_dotenv
 
@@ -12,6 +13,7 @@
 from github import (
     get_prs_waiting_for_review_by_reviewer,
     get_prs_with_changes_requested_by_reviewer,
+    get_pr_diff,
 )
 from linear.issues import (
     get_completed_issues,
@@ -64,6 +66,28 @@ def get_slack_markdown_by_linear_username(username):
     return "No Assignee"
 
 
+def _get_pr_diffs(issue):
+    """Return a list of diffs for PRs linked in the issue attachments."""
+    diffs = []
+    for attachment in issue.get("attachments", {}).get("nodes", []):
+        metadata = attachment.get("metadata", {})
+        url = metadata.get("url")
+        if not url:
+            continue
+        match = re.search(r"github.com/([^/]+)/([^/]+)/pull/(\d+)", url)
+        if not match:
+            continue
+        owner, repo, number = match.groups()
+        try:
+            diff = get_pr_diff(owner, repo, int(number))
+            diffs.append(diff)
+        except Exception as e:  # pragma: no cover - network errors are ignored
+            logging.error(
+                "Failed to fetch diff for %s/%s#%s: %s", owner, repo, number, e
+            )
+    return diffs
+
+
 @with_retries
 def post_priority_bugs():
     config = load_config()
@@ -371,13 +395,17 @@ def post_weekly_changelog():
         comments = " ".join(
             c.get("body", "") for c in issue.get("comments", {}).get("nodes", [])
         )
-        chunks.append(
-            f"ID: {issue['id']}\n"
-            f"Title: {issue['title']}\n"
-            f"Platform: {issue.get('platform', '')}\n"
-            f"Description: {desc}\n"
-            f"Comments: {comments}"
-        )
+        diffs = _get_pr_diffs(issue)
+        chunk_parts = [
+            f"ID: {issue['id']}",
+            f"Title: {issue['title']}",
+            f"Platform: {issue.get('platform', '')}",
+            f"Description: {desc}",
+            f"Comments: {comments}",
+        ]
+        if diffs:
+            chunk_parts.append("Diff:\n" + "\n".join(diffs))
+        chunks.append("\n".join(chunk_parts))
 
     instructions = (
         "Create a short customer-facing changelog from the provided issues. "
@@ -386,6 +414,7 @@ def post_weekly_changelog():
         "List each change as a short sentence with no markdown or bullet characters. "
         "Ignore technical tasks, internal changes, and unfinished work. "
         "Ensure each change appears only once in the changelog. "
+        "When a chunk includes a 'Diff:' section, use that diff as additional context. "
         "Return a JSON object with keys 'New Features', 'Bug Fixes', and 'Improvements'. "
         "Each item should be an object with fields 'id' (the issue id)"
         "and 'summary' (the changelog text)."