Valid Use Case for Copilot

Our compay proides us with GitHub copilot, which is yet another example of an “AI” engine. I’ve reviewed it before and I wasn’t particulary impressed. It writes mediocre code.

However, I found a use case where it really shines. I was setting up the blank project repositories for our upcoming hackathon. This involved creating a bunch of otherwise empty repositories with a customize README.md file. The simple solution was to automate this with an ad hoc shell script.

I don’t make a practice of writing shell scripts. I write a few every now and then, but I don’t live and breathe bash. It takes me a while because I forget the flags. I have to look up the exact syntax for things like the find command. Then I have to fight with the shell to get the quoting and escaping right. It’s a tedious chore. No doubt I would become adept at it if it were something I did daily, but it’s not.

So I decided to ask GitHub copilot to write some scripts for me. I gave it my problem statement: start with a file with a list of repository and description pairs. For each pair, look for the subdirectory with that name and descend into it. Use the sed command to modify the README.md file in the subdirectory to add the repository discription. Then use git to commit and push the change.

Copilot gave this a couple of seconds thought and came up with this script:

while IFS= read -r line; do
  dir_name=$(echo "$line" | cut -d' ' -f1)
  description=$(echo "$line" | cut -d' ' -f2-)
  if [ -d "$dir_name" ]; then
    sed -i "s/\[\[github_repo_description\]\]/$description/g" "$dir_name/README.md"
  else
    echo "Directory $dir_name does not exist."
  fi
done < descriptions.txt

find . -type d -name "hack*" -exec sh -c '
  cd "$0"
  if [ -f README.md ]; then
    git add README.md
    git commit -m "Update description."
    git push
  fi
' {} \;       

It isn’t a script that’d I’d write home about, but it got the job done. I ran the script and had the repositories set up in couple of minutes. I could have written the script myself, but it would have take me longer. I had forgotten the options to the find command. I had forgotten the arguments to the cut command. I would have had to look them up. Copilot saved me that time.

A co-worker of mine questioned the engineering tradeoff of using a resource hog like generative AI to write crappy, throwaway shell scripts. From the standpoint of an indiviual developer, though, this is the first use case for copilot that I’ve where it actualy saved me time and effort.