Update pr_fetcher.py

pr_fetcher.py

@@ -1,28 +1,21 @@
 import requests
 
-def fetch_pr_diff(repo_owner, repo_name, pr_number, github_token):
-    """
-    Fetches the diff of a pull request from a GitHub repository.
-
-    Args:
-        repo_owner (str): The owner of the GitHub repository.
-        repo_name (str): The name of the GitHub repository.
-        pr_number (int): The pull request number.
-        github_token (str): A personal access token for GitHub API.
-
-    Returns:
-        str: The diff text of the pull request, or an error message.
-    """
+def fetch_pr_diff(owner, repo, pr_number, token=None):
     headers = {
-        "Accept": "application/vnd.github.v3.diff",
-        "Authorization": f"Bearer {github_token}"
+        "Accept": "application/vnd.github.v3.diff"
     }
+    if token:
+        headers["Authorization"] = f"token {token}"
 
-    url = f"https://api.github.com/repos/{repo_owner}/{repo_name}/pulls/{pr_number}"
+    url = f"https://api.github.com/repos/{owner}/{repo}/pulls/{pr_number}"
 
     response = requests.get(url, headers=headers)
 
     if response.status_code == 200:
         return response.text
+    elif response.status_code == 404:
+        return "Error: PR not found. Check the repo and PR number."
+    elif response.status_code == 401:
+        return "Error: Unauthorized. Check your GitHub token."
     else:
-        return f"Error {response.status_code}: {response.text}"
+        return f"Error: Could not fetch PR. Status code: {response.status_code}"