Some functions for .bashrc/.zshrc to make working with PRs from forks easier

git.zsh

gco-pr(){
  git fetch origin pull/$1/head:$1 && git checkout $1
}
gp-pr(){
  branch="$(git branch --show-current)"

  remote_organisation="$(echo "$1" | sed 's/:.*//')"
  remote_branch="$(echo "$1" | sed 's/.*://')"

  origin="$(git remote get-url origin)"

  if [[ "$origin" == "git@"* ]]; then
    # parse ssh remote
    host="$(echo "$origin" | sed -E 's/git@([^:]+):([^\/]+)\/(.+)\.git/\1/')"
    organisation="$(echo "$origin" | sed -E 's/git@([^:]+):([^\/]+)\/(.+)\.git/\2/')"
    repo="$(echo "$origin" | sed -E 's/git@([^:]+):([^\/]+)\/(.+)\.git/\3/')"

    echo git push "git@$host:$remote_organisation/$repo.git" "$branch:$remote_branch"
    git push "git@$host:$remote_organisation/$repo.git" "$branch:$remote_branch"
  else
    # parse https remote
    host="$(echo "$origin" | sed -E 's/https:\/\/([^/]+)\/([^\/]+)\/(.+)\.git/\1/')"
    organisation="$(echo "$origin" | sed -E 's/https:\/\/([^/]+)\/([^\/]+)\/(.+)\.git/\2/')"
    repo="$(echo "$origin" | sed -E 's/https:\/\/([^/]+)\/([^\/]+)\/(.+)\.git/\3/')"

    echo git push "https://$host/$remote_organisation/$repo.git" "$branch:$remote_branch"
    git push "https://$host/$remote_organisation/$repo.git" "$branch:$remote_branch"
  fi
}

I should probably mention that gco-pr takes the PR number as argument and gp-pr takes the remote user and branch separated by a colon which is what you get when you click the copy button next to the source branch name when viewing a GitHub PR.