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| author | Cameron McEfee <cameron@github.com> | 2011-06-06 18:43:16 -0700 |
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| committer | Cameron McEfee <cameron@github.com> | 2011-06-06 18:43:16 -0700 |
| commit | 68b2217289711a4b78c0476b404b351afbbe655f (patch) | |
| tree | 7aa27243949667d1c12ee6518eb8063d83d11c97 /_posts/2008-01-08-send-pull-requests.md | |
| parent | 3f78d29f08fda99eda887aad14f99baf1c71636e (diff) | |
| parent | 7edd04eeaa188cf0e87dfc71b2278785dcdf7ed6 (diff) | |
Merge pull request #30 from github/reorder-nav
Reorder nav, reduce each post to one category, rename for usability
Diffstat (limited to '_posts/2008-01-08-send-pull-requests.md')
| -rw-r--r-- | _posts/2008-01-08-send-pull-requests.md | 239 |
1 files changed, 239 insertions, 0 deletions
diff --git a/_posts/2008-01-08-send-pull-requests.md b/_posts/2008-01-08-send-pull-requests.md new file mode 100644 index 0000000..d45bbf0 --- /dev/null +++ b/_posts/2008-01-08-send-pull-requests.md @@ -0,0 +1,239 @@ +--- +layout: default +title: Send pull requests +description: How to notify others of your changes using Pull Requests. +categories: beginner +--- + +<style type="text/css"> +.main img { + border:1px solid #eee; + padding:5px; +} +.main img.inline { + vertical-align:middle; + border:0; +} +</style> + +<p class="intro">Pull requests let you tell others about changes you've pushed to a GitHub +repository. Once a pull request is sent, interested parties can review the set +of changes, discuss potential modifications, and even push follow-up commits if +necessary.</p> + +<p class="intro">This guide walks through the process of sending a hypothetical pull request and +using the various code review and management tools to take the change to +completion.</p> + +## A Quick Note on Collaborative Development Models + +There are two popular models of collaborative development on GitHub: + + 1. The *Fork + Pull Model* lets anyone fork an existing repository and + push changes to their personal fork without requiring access be granted + to the source repository. The changes must then be pulled into the source + repository by the project maintainer. This model reduces the amount of + friction for new contributors and is popular with open source projects + because it allows people to work independently without upfront + coordination. + + 2. The *Shared Repository Model* is more prevalent with small teams and + organizations collaborating on private projects. Everyone is granted push + access to a single shared repository and topic branches are used to isolate + changes. + +Pull requests are especially useful in the *Fork + Pull Model* because they +provide a way to notify project maintainers about changes in your fork. However, +they're also useful in the *Shared Repository Model* where they're used to +initiate code review and general discussion about a set of changes before being +merged into a mainline branch. + +## Before You Begin + +This guide assumes that [you have a GitHub account](http://github.com/signup), +that you've forked an existing repository and pushed your changes. For help with +forking and pushing changes, see the [Forking a project](/forking/) topic. + +## Initiating The Pull Request + +In the following example, **kneath** has completed some work on an error page +for the GitHub Jobs web application, pushed three commits to a topic branch in +his fork, and would like someone to review and merge. + +Navigate to **your repository** with the changes you want someone else to pull and +press the *Pull Request* button. + + + +Pull requests can be sent from any branch or commit but it's recommended that a +topic branch be used so that follow-up commits can be pushed to update the pull +request if necessary. + +## Previewing The Pull Request + +After pressing the *Pull Request* button, you are presented with a preview page +where you can enter a title and optional description, see exactly what +commits will be included when the pull request is sent, and also see who the +pull request will be sent to: + + + +If you're sending from a topic branch, the title is pre-filled based on the name +of the branch. Markdown is supported in the description, so you can embed images +or use preformatted text blocks. + +Switch to the *Commits* tab to ensure that the correct set of changes is being +sent: + + + +Review the diff of all changes by switching to the *Files Changed* tab: + + + +## Changing The Commit Range and Destination Repository + +By default, pull requests are assumed to be based on the parent-most +repository's integration branch. In this case, the `kneath/jobs` repository was +forked from `github/jobs` so the pull request is assumed to be based on the +`master` branch of the `github/jobs` repository. In a great majority of cases, +the defaults will be right; however, if any of this information is incorrect, press +the *Change Commits* button. + + + +The commit range selector will expand, allowing the base repository, base +branch, and head branch to be customized: + + + +The easiest way of thinking about the commit range is this: the *base branch* is +**where** you think changes should be applied, the *head branch* is **what** you +would like to be applied. + +Changing the base repository changes who is notified of the pull request. +Everyone that can push to the base repository will receive an email notification +and see the new pull request in their dashboard the next time they log in. + +Once you're happy with the commit range, press the *Update Commit Range* button +to update the commit and files changed preview areas. + +## Sending The Pull Request + +Once you've entered the title and description, made any necessary customizations +to the commit range, and reviewed the commits and file changes to be sent, press +the *Send pull request* button. + + + +The pull request is sent immediately. You're taken to the main pull request +discussion and review page. Additionally, all repository collaborators and +followers will see an event in their dashboard: + + + +## Managing Pull Requests + +All pull requests sent or received by you are browseable through the pull +request dashboard. + + + +Pull requests for a specific repository are also browseable by anyone with +access by visiting the *Network -> Pull Requests* page. + + + +The pull request dashboard and the repository pull request list support a wide +range of filtering and sorting controls. Use them to narrow down the list to +the pull requests you're interested in. + +## Reviewing Proposed Changes + +When you receive a pull request, the first thing to do is review the set of +proposed changes. Pull requests are tightly integrated with the underlying git +repository, so you can see exactly what commits would be merged should the +request be accepted: + + + +You can also review the cumulative diff of all file changes across all commits. + + + +## Pull Request Discussion + +After reviewing the basic description, commits, and cumulative diff, the person +tasked with applying the changes may have questions or comments. Perhaps the +coding style doesn't match project guideline, or the change is missing unit +tests, or maybe everything looks great and some props are in order. The +discussion view is designed to encourage and capture this type of discussion. + + + +The discussion view starts with the pull request's original title and +description and then captures additional activity to display chronologically +from there. Any of the following types of activity are captured as they happen: + + * Comments left on the pull request itself. + * Additional commits pushed to the pull request's branch. + * File and line notes left on any of the commits included in the pull request's range. + +Pull request comments are Markdown compatible, so you can embed images, use +preformatted text blocks, and other formatting supported by Markdown. + +## Merging a Pull Request + +Once the pull request is deemed satisfactory, someone with push access to the +destination repository must apply the changes and push the updated branch. +There are a variety of ways to accomplish this. Three popular methods are +described below. + +#### Fetch and Merge + +This is the most common method of fetching and applying changes. It requires +adding a remote for the person that sent the pull request, fetching from that +repository, merging the requested branch, fixing any conflicts, and pushing +the newly merged branch back to the repository: + +<pre class="console"> +<span>$</span> git checkout master +<span>$</span> git remote add kneath git://github.com/kneath/jobs.git +<span>$</span> git fetch kneath +<span>$</span> git merge kneath/error-page +<span>$</span> git push origin master +</pre> + +#### Patch and Apply + +The *fetch and merge* approach works great when you're working on a team or +repeatedly applying changes from the same small group of people. Another +approach that's a bit quicker in one-off cases is to use `git-am`. + +Every pull request has a `.patch` URL where you can grab a textual patch file +to feed into the `git-am` command: + +<pre class="console"> +<span>$</span> git checkout master +<span>$</span> curl http://github.com/github/jobs/pull/25.patch | git am +<span>$</span> git push origin master +</pre> + +#### Auto Merge + +In many cases it is possible to ask github to auto merge a pull request using +the merge button. This was made possible with the launch of Pull Requests 2.0 +and is covered in the [related blog post](https://github.com/blog/843-the-merge-button). + +## Closing a Pull Request + +Pull Requests are automatically closed when the requested commits are merged +into the destination repository. An event is generated to let all repository +collaborators and followers know that the merge occurred: + + + +It's also possible to manually close a pull request in cases where the set of +changes are rejected. This is also sometimes necessary if the changes are +applied with `git-cherry-pick` or using some other mechanism that disallows the +merge from being detected. |
