Handle repositories that don't support draft PRs

CHANGES.md

@@ -0,0 +1,13 @@
+# Changes
+
+This PR adds support for handling repositories that don't support draft PRs. When attempting to create a draft PR in a repository that doesn't support this feature, the code will now gracefully fall back to creating a regular PR instead of failing.
+
+## Implementation Details
+
+1. Modified the `create_pull` method in the `GitRepoClient` class to:
+   - First attempt to create a draft PR when requested
+   - Catch GitHub exceptions with status code 422 that mention "draft" in the error message
+   - Fall back to creating a regular PR when draft PRs aren't supported
+   - Log appropriate warning messages
+
+This change ensures that the PR creation process is more robust and works across all GitHub repositories, including older GitHub Enterprise Server instances that may not support draft PRs.

src/codegen/git/clients/git_repo_client.py

@@ -200,10 +200,31 @@ def create_pull(
         if base_branch_name is None:
             base_branch_name = self.default_branch
         try:
-            pr = self.repo.create_pull(title=title or f"Draft PR for {head_branch_name}", body=body or "", head=head_branch_name, base=base_branch_name, draft=draft)
-            logger.info(f"Created pull request for head branch: {head_branch_name} at {pr.html_url}")
-            # NOTE: return a read-only copy to prevent people from editing it
-            return self.repo.get_pull(pr.number)
+            # First attempt to create with draft=True if requested
+            if draft:
+                try:
+                    pr = self.repo.create_pull(title=title or f"Draft PR for {head_branch_name}", body=body or "", head=head_branch_name, base=base_branch_name, draft=True)
+                    logger.info(f"Created draft pull request for head branch: {head_branch_name} at {pr.html_url}")
+                    # NOTE: return a read-only copy to prevent people from editing it
+                    return self.repo.get_pull(pr.number)
+                except GithubException as ge:
+                    # Check if the error is related to draft PR support (422 Unprocessable Entity)
+                    if "422" in str(ge) and "draft" in str(ge).lower():
+                        logger.warning("Repository doesn't support draft PRs. Creating regular PR instead.")
+                        # Fall back to non-draft PR
+                        pr = self.repo.create_pull(title=title or f"PR for {head_branch_name}", body=body or "", head=head_branch_name, base=base_branch_name, draft=False)
+                        logger.info(f"Created regular pull request for head branch: {head_branch_name} at {pr.html_url}")
+                        # NOTE: return a read-only copy to prevent people from editing it
+                        return self.repo.get_pull(pr.number)
+                    else:
+                        # Re-raise if it's not a draft PR support issue
+                        raise
+            else:
+                # If draft is not requested, create a regular PR
+                pr = self.repo.create_pull(title=title or f"PR for {head_branch_name}", body=body or "", head=head_branch_name, base=base_branch_name, draft=False)
+                logger.info(f"Created pull request for head branch: {head_branch_name} at {pr.html_url}")
+                # NOTE: return a read-only copy to prevent people from editing it
+                return self.repo.get_pull(pr.number)
         except GithubException as ge:
             logger.warning(f"Failed to create PR got GithubException\n\t{ge}")
         except Exception as e: