check out a "pull request" on Git to review/test a PR

Question

We have a repo that I have added to my local fork as Upstream. Someone sent a PR and I want to review it. Although I'm able to review code on Github by their Diff tool but I want to have it on my local machine and test it on a real device in order to make sure it works fine (Android repo it is).

What is best way to checkout this PR?

Answer 1

It's somewhat underdocumented, but GitHub provides pull requests as branches on your Upstream repository so you don't need to add remotes for each third party who might send you a pull request.

So

git fetch Upstream pull/1044/head:pr1044-from-someone

will make the commits in the pull request available in your local repository in a new branch, pr1044-from-someone, which you can review and merge locally as appropriate.

See help.github.com's Modifying an inactive pull request locally for more details.

Answer 2

Another option is

• add the PR's repository as a remote in your local copy

  git remote add remote_name github.com/user/proj
  

• fetch changes from this remote

  git fetch remote_name branch_name_to_fetch
  

• checkout the changes using

  git checkout remote_name/branch_name_to_fetch
  

And now you can test it as per your needs on your local, you can create new branch, take a diff between branches, and so on.

PS: IMO, this is slightly tedious compared to your current approach - if you get a lot of pull requests, adding all the remotes can be confusing and fetching all the branch history is sub-optimal, a patch is perfect.

Answer 3

I just figured it out how to do that. Let me explain what I did for everyone how has same question.

1. Goto PR page on Github. The URL should looks like https://github.com/YOUR-NAME/REPO-NAME/pull/1044/files
2. Add .patch at the end of URL and hit Enter so the URL looks like https://github.com/YOUR-NAME/REPO-NAME/pull/1044/files.patch
3. Download this file or if is not downloadable create a text file, copy page and paste it into text file. Make sure the extension file is .patch (not .txt)
4. Create a new local branch and checkout into that branch
5. Take a look at what changes are in the patch by following command. This is just stat and doesn't apply anything: git apply --stat fix_empty_poster.patch
6. By following command you will see how close to trouble you are :) If there is no complain be happy: git apply --check fix_empty_poster.patch
7. Finally you can patch it by following command: git am --signoff < fix_empty_poster.patch

Now, you have a copy of branch for review.

More references:

1. GitHub Tip: download commits as patches
2. How to create and apply a patch with Git