diff_extractor.py

import difflib

from azdo_client import AzDOClient

MAX_FILES = 20
SKIP_CHANGE_TYPES = {"delete"}


def extract_unified_diffs(client: AzDOClient, commit_diff: dict, base_commit: str, target_commit: str) -> list[dict]:
    results = []

    for change in commit_diff.get("changes", []):
        item = change.get("item", {})
        path = item.get("path")
        change_type = change.get("changeType", "")

        if not path or item.get("isFolder"):
            continue
        if change_type in SKIP_CHANGE_TYPES:
            continue

        try:
            base_lines = (
                client.get_file_content(path, base_commit).splitlines(keepends=True)
                if change_type != "add" else []
            )
            target_lines = client.get_file_content(path, target_commit).splitlines(keepends=True)
        except Exception as e:
            print(f"  Skipping {path}: {e}")
            continue

        diff = list(difflib.unified_diff(
            base_lines, target_lines,
            fromfile=f"a{path}",
            tofile=f"b{path}",
        ))

        if diff:
            results.append({
                "file": path,
                "diff": "".join(diff),
            })

        if len(results) >= MAX_FILES:
            break

    return results


# Usage: set AZDO_PR_REVIEWER_PAT and fill in your own org/project/repo/PR ID
if __name__ == "__main__":
    ORG = "<org>"
    PROJECT = "<project>"
    REPO = "<repo>"
    PR_ID = "<pr_id>"

    print("Fetching PR diff from Azure DevOps...")
    client = AzDOClient(ORG, PROJECT, REPO)

    pr = client.get_pull_request(PR_ID)
    base_commit = pr["lastMergeTargetCommit"]["commitId"]
    target_commit = pr["lastMergeSourceCommit"]["commitId"]
    commit_diff = client.get_commit_diff(base_commit, target_commit)

    print()

    print("Extracting unified diffs...\n")
    diffs = extract_unified_diffs(client, commit_diff, base_commit, target_commit)

    for i, d in enumerate(diffs, start=1):
        print("=" * 80)
        print(f"[{i}] FILE: {d['file']}")
        print("-" * 80)
        print(d["diff"])
        print()

    if not diffs:
        print("No diffs extracted.")