fastai-make-pr-branch

#!/usr/bin/env bash

# for usage and functionality information run this program w/o arguments

me=$(basename "$0")
if [[ "$#" -ne 4 ]]; then
    echo "This program will checkout a forked version of the original repository, sync it with the original, create a new branch and set it up for a PR."
    echo ""
    echo "usage:"
    echo ""
    echo "$me auth user_name repo_name new_branch_name"
    echo ""
    echo "parameters:"
    echo ""
    echo "  auth:   ssh or https (use ssh if your github account is setup to use ssh)"
    echo "  user:   your github username"
    echo "  repo:   repository name to fork/use"
    echo "  branch: name of the branch to create"
    echo ""
    echo "example:"
    echo ""
    echo "$me ssh my-github-username fastai new-feature-branch"
    echo ""
    echo "notes:"
    echo ""
    echo "- if the original repository has been already forked, it'll be done by the program (it will ask you for your github password)"
    echo "- if the program is run from a directory that already contains a checked out git repository that matches the parameters, it will re-use it instead of making a new checkout."
    echo "- if the requested branch already exists it'll reuse it"
    echo "- if the master is out of sync with the original master it'll sync it first"
    echo ""
    exit 0
fi

auth="$1"
user_name="$2"
repo_name="$3"
new_branch_name="$4"

orig_user_name="fastai"
path="$repo_name-$new_branch_name"

# abort the script on any failure
set -e

# check curl is available
function check_curl_is_available {
    command -v curl >/dev/null 2>&1 || { echo >&2 "$me requires 'curl' but it's not installed. Aborting."; exit 1; }
}

function run() {
    local cmd="$@"
    echo "running: $cmd"
    eval $cmd || exit 1
}

function master_sync() {
    run "git fetch upstream"
    run "git checkout master"
    # XXX: this will fail if the user was committing directly to their forked `master` branch is
    cmd="git merge --no-edit upstream/master"
    echo "running: $cmd"
    eval $cmd || { git merge --abort; echo -e >&2 "\nError: $user_name/$repo_name/master can't be merged with orig_user_name/$repo_name/master.\nYou must merge manually, or reset $user_name/$repo_name/master.\nSee:  https://docs-dev.fast.ai/git.html#how-to-reset-your-forked-master-branch\nAborting."; exit 1; }
    run "git push"

}

if [[ "$auth" == "ssh" ]]; then
    prefix="git@github.com:"
else
    prefix="https://github.com/"
fi
url="$prefix$user_name/$repo_name.git"

# fork the repo if it hasn't been forked yet
echo -e "\n\n*** Checking if we need to fork"
was_already_forked=0
git ls-remote $url >/dev/null 2>&1 && was_already_forked=1
if [[ "$was_already_forked" -eq 1 ]]; then
    echo "$url is already forked"
else
    echo "$url doesn't exist - need to fork"
    check_curl_is_available
    run "curl -u $user_name https://api.github.com/repos/fastai/$repo_name/forks -d ''"
fi

# support an already existing checkout if it matches the desired parameters, but only if it's not dirty
clone_is_needed=1
if [[ -e ".git" ]]; then
   echo "detected current dir to be a git repository"
   if [[ -n "$(git status -s)" ]]; then
       echo "git status is not clean, not going to re-use the current checkout"
       clone_is_needed=1
   else
       cur_url=$(git config --get remote.origin.url)
       if [[ "$cur_url" == "$url" ]]; then
           echo "already on the right repo, going to re-use the current checkout"
           clone_is_needed=0
       fi
   fi
fi

# clone
if [[ "$clone_is_needed" -eq 1 ]]; then
    echo -e "\n\n*** Cloning $url to $path"
    run "git clone $url $path"
    run "cd $path"
fi

# not all repos have this tool
tool="tools/run-after-git-clone"
if [[ -f $tool ]]; then
    echo -e "\n\n*** run fastai repository setup"
    run "python $tool"
fi

# setup this fork to track the upstream
echo -e "\n\n*** Setting up this fork to track the upstream"
orig_repo_url="$prefix$orig_user_name/$repo_name.git"
run "git remote add upstream $orig_repo_url || echo 'already exists'"
# show the setup
run "git remote -v"

# let's sync the forked repo master with the upstream master if it hasn't been just forked
if [[ "$was_already_forked" -eq 1 ]]; then
    echo -e "\n\n*** Syncing $user_name/master with $orig_user_name/master"
    master_sync
    echo "Done"
fi

# now create a branch
echo -e "\n\n*** Creating '$new_branch_name' branch and setting its upstream for an easy push"
branch_already_exists=0
git show-branch $new_branch_name >/dev/null 2>&1 && branch_already_exists=1
if [[ "$branch_already_exists" -eq 1 ]]; then
    echo "$new_branch_name already exists, switching to it"
    run "git checkout $new_branch_name"
else
    echo "$new_branch_name doesn't yet exist, creating"
    run "git checkout -b $new_branch_name"
    echo -e "'$new_branch_name' branch was successfully created"
fi

# set this branch's upstream, so to enable `git push` and other git
# commands without needing to pass any more arguments.
echo -e "\n\n*** Set this $new_branch_name's upstream to simplify push and alikes"
run "git push --set-upstream origin $new_branch_name"

# give parting instructions
echo -e "\n\n*** Next do: "
# only suggest to chdir if we made a clone
echo -e "1. Switch to the working dir:\n"
if [[ "$clone_is_needed" -eq 1 ]]; then
    echo -e "cd $path\n"
else
    echo -e "cd .\n"
fi
echo -e "2. Validate you're on the right repo/branch:\n"
echo -e "echo on repo: \$(git config --get remote.origin.url | sed 's|^.*//||; s/.*@//; s/[^:/]\+[:/]//; s/.git$//') branch: \$(git branch | sed -n '/\* /s///p')\n\n"
echo -e "3. And do your work.\n"
echo -e "4. When you're done:\n"
echo -e "git add <newfiles> # if you added new files"
echo -e "git commit -a      # if you want to commit all modified/added files"
echo -e "git push           # push files into $new_branch_name branch\n"
echo -e "5. Then go to:\n"
echo -e "  https://github.com/$user_name/$repo_name/tree/$new_branch_name\n"
echo "review your changes and when you're happy with what you see, submit your PR."
echo "While it's very good to review your PR on github before submitting it, if you want to use a CLI solution, there are several solutions to choose from:"
echo "* https://github.com/github/hub"
echo "* https://github.com/jd/git-pull-request"
echo "* https://github.com/jehiah/git-open-pull"
echo "* https://www.npmjs.com/package/pullr"