helper (#31152)

* helper

* Apply suggestions from code review
Co-authored-by: amyeroberts <22614925+amyeroberts@users.noreply.github.com>

* updates

* more doc

---------
Co-authored-by: amyeroberts <22614925+amyeroberts@users.noreply.github.com>

utils/patch_helper.py

+# coding=utf-8
+# Copyright 2024 The HuggingFace Inc. team. All rights reserved.
+#
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+"""
+This should help you prepare a patch, automatically extracting the commits to cherry-pick
+in chronological order to avoid merge conflicts. An equivalent way to do this is to use
+`git log --pretty=oneline HEAD...v4.41.0` and grep.
+
+Potential TODO: automatically cherry-picks them.
+
+Pass in a list of PR:
+`python utils/patch_helper.py --prs 31108 31054 31008 31010 31004`
+will produce the following:
+```bash
+Skipping invalid version tag: list
+Skipping invalid version tag: localattn1
+Git cherry-pick commands to run:
+git cherry-pick 03935d300d60110bb86edb49d2315089cfb19789 #2024-05-24 11:00:59+02:00
+git cherry-pick bdb9106f247fca48a71eb384be25dbbd29b065a8 #2024-05-24 19:02:55+02:00
+git cherry-pick 84c4b72ee99e8e65a8a5754a5f9d6265b45cf67e #2024-05-27 10:34:14+02:00
+git cherry-pick 936ab7bae5e040ec58994cb722dd587b9ab26581 #2024-05-28 11:56:05+02:00
+git cherry-pick 0bef4a273825d2cfc52ddfe62ba486ee61cc116f #2024-05-29 13:33:26+01:00
+```
+"""
+
+import argparse
+
+from git import GitCommandError, Repo
+from packaging import version
+
+
+def get_merge_commit(repo, pr_number, since_tag):
+    try:
+        # Use git log to find the merge commit for the PR within the given tag range
+        merge_commit = next(repo.iter_commits(f"v{since_tag}...HEAD", grep=f"#{pr_number}"))
+        return merge_commit
+    except StopIteration:
+        print(f"No merge commit found for PR #{pr_number} between tags {since_tag} and {main}")
+        return None
+    except GitCommandError as e:
+        print(f"Error finding merge commit for PR #{pr_number}: {str(e)}")
+        return None
+
+
+def main(pr_numbers):
+    repo = Repo(".")  # Initialize the Repo object for the current directory
+    merge_commits = []
+
+    tags = {}
+    for tag in repo.tags:
+        try:
+            # Parse and sort tags, skip invalid ones
+            tag_ver = version.parse(tag.name)
+            tags[tag_ver] = tag
+        except Exception:
+            print(f"Skipping invalid version tag: {tag.name}")
+
+    last_tag = sorted(tags)[-1]
+    major_minor = f"{last_tag.major}.{last_tag.minor}.0"
+    # Iterate through tag ranges to find the merge commits
+    for pr in pr_numbers:
+        commit = get_merge_commit(repo, pr, major_minor)
+        if commit:
+            merge_commits.append(commit)
+
+    # Sort commits by date
+    merge_commits.sort(key=lambda commit: commit.committed_datetime)
+
+    # Output the git cherry-pick commands
+    print("Git cherry-pick commands to run:")
+    for commit in merge_commits:
+        print(f"git cherry-pick {commit.hexsha} #{commit.committed_datetime}")
+
+
+if __name__ == "__main__":
+    parser = argparse.ArgumentParser(description="Find and sort merge commits for specified PRs.")
+    parser.add_argument("--prs", nargs="+", required=True, type=int, help="PR numbers to find merge commits for")
+
+    args = parser.parse_args()
+    main(args.prs)