From 155e85523e56eb56b485e5cc43a04dad67183640 Mon Sep 17 00:00:00 2001
From: Stefanni Brasil <stefannibrasil@gmail.com>
Date: Tue, 8 Aug 2023 09:30:25 -0600
Subject: [PATCH] Add git co-upstream-pr command (#726)

* Add git co-upstream-pr

When reviewing Pull Requests from open source projects, it's handy
to have a way to just pass the PR number and the local branch name.

With this new command, to fetch a PR from an upstream remote repo,
we just need the PR number and the name of the local branch:

$ co-upstream-pr 001 test_generator_pr

git will checkout the upstream PR in the local test_generator_pr branch.

If there is no upstream remote set, we get a nice message guiding
users to set it first.

Co-authored-by: Mina Slater <mina@thoughtbot.com>

* Use heredoc to send output into cat instead of using echo and multi-line quotes

* Subcommand, not alias

* Fail gracefully and exit if PR number or local branch name are not provided

Co-authored-by: Mike Burns <mburns@thoughtbot.com>

---------

Co-authored-by: Mina Slater <mina@thoughtbot.com>
Co-authored-by: Mike Burns <mburns@thoughtbot.com>
---
 README.md              |  1 +
 bin/git-co-upstream-pr | 24 ++++++++++++++++++++++++
 2 files changed, 25 insertions(+)
 create mode 100755 bin/git-co-upstream-pr

diff --git a/README.md b/README.md
index e02aa3697f..e700e5c5f8 100644
--- a/README.md
+++ b/README.md
@@ -198,6 +198,7 @@ configuration:
 
 [git](http://git-scm.com/) configuration:
 
+- Adds a `co-upstream-pr $PR_NUMBER $LOCAL_BRANCH_NAME` subcommand to checkout remote upstream branch into a local branch.
 - Adds a `create-branch` alias to create feature branches.
 - Adds a `delete-branch` alias to delete feature branches.
 - Adds a `merge-branch` alias to merge feature branches into master.
diff --git a/bin/git-co-upstream-pr b/bin/git-co-upstream-pr
new file mode 100755
index 0000000000..f427e8d9b4
--- /dev/null
+++ b/bin/git-co-upstream-pr
@@ -0,0 +1,24 @@
+#!/bin/sh
+
+set -e
+
+pull_request_number=$1
+local_branch_name=$2
+
+if [ -z "$pull_request_number" -o -z "$local_branch_name" ]; then
+  echo "usage: git co-upstream-pr <pull_request_number> <local_branch_name>"
+  exit 1
+fi
+
+if git remote -v | grep -q upstream; then
+  git fetch upstream "pull/$pull_request_number/head:$local_branch_name"
+  git checkout "$local_branch_name"
+else
+  cat <<HELP
+You don't have an upstream remote set.
+Use:
+  git remote add upstream {upstream_remote_url}
+
+to set the reference and then try again.
+HELP
+fi