The other day, I received a review request from a colleague. There were a staggering 100 files in the diff—my jaw dropped.
It is impossible for a human to implement such a large-scale change manually. They definitely used an AI agent. The task involved migrating CSV exports within the project to an Excel format. If these 100 files had been replaced mechanically—for instance, simply changing /path/hogehoge.csv to /path/hogehoge.xlsx across the board—I wouldn’t have had any complaints, and a 100-file diff would have been fine.
However, the changes included logic modifications, file deletions, creations, and migrations of test locations. I understand that the issue involved significant changes, but why bundle it all into a single Pull Request? Why not check the diff yourself to see if there are any issues before requesting a review? I spent four hours reviewing this. A typical PR review for me takes less than 10 minutes. The PR contained changes clearly outside the scope of the task, such as DB schema modifications, which have nothing to do with replacing CSV files with Excel files. There were also model changes and new controller/action additions (which Rails engineers will understand).
