Merge remote-tracking branch 'upstream/pull/3771'

[rails.git] / CONTRIBUTING.md

diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 61e23f810d39b921ef717ba7e723ced5f9366221..5ee4e01736634679b6f233323ca41db878c653ea 100644 (file)
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -23,7 +23,7 @@ so with any new functionality which is written. Tests are also useful
 in giving others confidence in the code you've written, and can
 greatly speed up the process of merging in new code.
 
-When hacking, you should:
+When contributing, you should:
 
 * Write new tests to cover the new functionality you've added.
 * Where appropriate, modify existing tests to reflect new or changed
@@ -56,9 +56,9 @@ more importantly, **why** it does that. Good comments help your fellow
 developers to read the code and satisfy themselves that it's doing the
 right thing.
 
-When hacking, you should:
+When contributing, you should:
 
-* Comment your code - don't go overboard, but explain the bits which
+* Comment your code where necessary - explain the bits which
 might be difficult to understand what the code does, why it does it
 and why it should be the way it is.
 * Check existing comments to ensure that they are not misleading.
@@ -79,24 +79,16 @@ database, and update the list of available keys manually.
 Adding or removing keys to this list is therefore discouraged, but contributions
 to the descriptive texts are welcome.
 
-## Code Documentation
-
-To generate the HTML documentation of the API/rails code, run the command
-
-```
-rake doc:app
-```
-
 ## Committing
 
-When you submit patches, the project maintainer has to read them and
+When you submit your changes, the project maintainers have to read them and
 understand them. This is difficult enough at the best of times, and
-misunderstanding patches can lead to them being more difficult to
-merge. To help with this, when submitting you should:
+misunderstanding commits can lead to them being more difficult to
+merge. To help with this, when committing you should:
 
-* Split up large patches into smaller units of functionality.
+* Split up large commits into smaller units of functionality.
 * Keep your commit messages relevant to the changes in each individual
-unit.
+commit.
 
 When writing commit messages please try and stick to the same style as
 other commits, namely:
@@ -108,12 +100,37 @@ other commits, namely:
 For simple commits the one line summary is often enough and the body
 of the commit message can be left out.
 
-## Sending the patches
+## Pull Requests
 
 If you have forked on GitHub then the best way to submit your patches is to
 push your changes back to GitHub and then send a "pull request" on GitHub.
 
-Otherwise you should either push your changes to a publicly visible git repository
-and send the details to the [rails-dev](https://lists.openstreetmap.org/listinfo/rails-dev)
-list or generate patches with `git format-patch` and send them to the
-[rails-dev](https://lists.openstreetmap.org/listinfo/rails-dev) list.
+If your pull request is small, for example one or two commits each containing
+only a few lines of code, then it is easy for the maintainers to review.
+
+If you are creating a larger pull request, then please help the maintainers
+with making the reviews as straightforward as possible:
+
+* The smaller the PR, the easier it is to review. In particular if a PR is too
+  large to review in one sitting, or if changes are requested, then the
+  maintainer needs to repeatedly re-read code that has already been considered.
+* The commit history is important. This is a large codebase, developed over many
+  years by many developers. We frequently need to read the commit history (e.g.
+  using `git blame`) to figure out what is going on. So small, understandable,
+  and relevant commits are important for other developers looking back at your
+  work in future.
+
+If you are creating a large pull request then please:
+
+* Consider splitting your pull request into multiple PRs. If part of your work
+  can be considered standalone, or is a foundation for the rest of your work,
+  please submit it separately first.
+* Avoid including "fixup" commits. If you have added a fixup commit (for example
+  to fix a rubocop warning, or because you changed your own new code) please
+  combine the fixup commit into the commit that introduced the problem.
+  `git rebase -i` is very useful for this.
+* Avoid including "merge" commits. If your PR can no longer be merged cleanly
+  (for example, an unrelated change to Gemfile.lock on master now conflicts with
+  your PR) then please rebase your PR onto the latest master. This allows you to
+  fix the conflicts, while keeping the PR a straightforward list of commits. If
+  there are no conflicts, then there is no need to rebase anything.