[[merging-a-pull-request]]
= Merging a Pull Request

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:page-partial:

The process for merging in github pull requests (so that they can be tested locally before committing) has been scripted in the `github-pr.sh` script.

NOTE: Alternatively, if you are confident using _git_ from within your IDE,
consider the specific IDE setup guides xref:conguide:eclipse:about.adoc[Eclipse]
and xref:conguide:intellij:about.adoc[IntelliJ].

The script will merge the fork into a temporary branch, and then run a build.
Once you are happy, you can commit.

== Process and Usage

The overall process is as follows:

* locate/raise corresponding JIRA ticket, eg CAUSEWAY-1162
* checkout branch from which PR was forked (usually just 'main')
* merge PR into temporary branch using the `github-pr.sh` script
* test the change locally (run the app, rebuild, manual regression tests etc)
* if required, tidy up/refactor code as required
* merge temporary branch into mainline, and commit

This link:https://youtu.be/CKSLZBBHjME[screencast] also shows the process.

== Prerequisites

The script uses 'jq' to parse JSON. To install:

* on Linux: +
+
[source,bash]
----
aptitude install jq
----

* on MacOS: +
+
[source,bash]
----
brew install jq
----

* on Windows: +
+
Download exe from http://stedolan.github.io/jq/download/[website]

== Syntax

The syntax is:

[source,bash]
----
github-pr.sh -j 1162 -g 31 [-s] [-p CAUSEWAY]
----

where:

* `-j 1162`
+
is the JIRA ticket number

* `-g 31`
+
is the github PR issue number

* `-s`
+
will optionally skip the build and auto-merge

* `-p CAUSEWAY`
+
optionally overrids the JIRA project (defaults to 'CAUSEWAY')

== Example transcript

The listing below shows the steps taken by the script:

[source,bash]
----
$ sh github-pr.sh causeway 1162 31

Found JIRA ticket
Found github PR
branch_name_local: main
username         : sebadiaz
repo_full_name   : sebadiaz/causeway
repo_clone_url   : https://github.com/sebadiaz/causeway.git
branch_name_fork : main

merging into: CAUSEWAY-1162_pr-31

Deleting branch 'CAUSEWAY-1162_pr-31'
Deleted branch CAUSEWAY-1162_pr-31 (was bd2e3c2).
Creating the branch CAUSEWAY-1162_pr-31
Switched to a new branch 'CAUSEWAY-1162_pr-31'
Pulling the changes from https://github.com/sebadiaz/causeway.git main
From https://github.com/sebadiaz/causeway
 * branch            main     -> FETCH_HEAD
Auto-merging core/pom.xml
Merge made by the 'recursive' strategy.
 core/pom.xml                                       |   3 +-
 .../apache/causeway/security/shiro/CausewayLdapRealm.java  | 198 +++++++++++++++++++--
 2 files changed, 186 insertions(+), 15 deletions(-)

Merged the PR; hit enter to build
----

The build now commences.
Once done, the script continues:

[source,bash]
----
If build successful and happy to merge, execute:

git checkout main && git merge --no-ff CAUSEWAY-1162_pr-31 && git branch -d CAUSEWAY-1162_pr-31
----

The screenshot belows shows the history we end up with:

image::committers/github-pr-history.png[]

This shows the fork being merged into the temporary branch ("CAUSEWAY-1162_pr-31"), then some further tidy-up, and finally the merging of the temporary branch into mainline.

Note that there is no rebasing in this model.
This is intentional: when the merged branch is pushed, github will automatically close the original pull request.




