Page History

...

This following steps documents the workflow to get you started with contributing code to Apache Daffodil.

1. If you have not done so already, we reccomend you:
   Sign up for an account in JIRA
   do not have a JIRA account, request one by visiting https://selfserve.apache.org/jira-account.html. Once granted, you will be able to assign bugs to yourself and create new bugs.
    
2. Subscribe to the dev@daffodil.apache.org mailing list by sending an email to 

   You may also want to subscribe to the dev@daffodil.apache.org and commits@daffodil.apache.org mailing lists by sending an email to

   dev-subscribe@daffodil.apache.org

    and following the instructions.
   

   Send an email to the dev@daffodil.apache.org mailing list requesting Jira contributor access. For example:

   Code Block
   I would like to contribute to the Daffodil project! Please grant me Jira contributor access. My Jira user name is: ...

   Once granted, you will be able to assign bugs to yourself and create new bugs.

   and commits-subscribe@daffodil.apache.org, respectively, and following the instructions.

    

3. Search for an existing issue or create a new issue in JIRA that represents the change you would like to make or bug to fix.
   
   If you are a beginner to Daffodil development, a good place to start is with the Daffodil beginner bugs.
   
   See the Daffodil Issue Tracker information for creating issues and what information/discussions should take place in JIRA.
    

4. Assign the issue to yourself so others know that you are working on it.
   
   

5. Visit the Apache Daffodil GitHub and create a fork by clicking on "Fork" in the top right.
    

6. Clone your new fork using ssh (you will need to create an ssh key and add it to GitHub if you haven't already). This will be your origin remote:

   Code Block
   language bash
   $ git clone git@github.com:<github_username>/daffodil.git $ cd daffodil

   
   

7. Add the ASF upstream repository as a new git remote, calling it asf:

   Code Block
   language bash
   $ git remote add asf https://github.com/apache/daffodil.git $ git fetch asf

   It is also recommended to change the push URL of the asf remote to a nonsense string to prevent accidentally pushing to it--branches should only be pushed to your fork:

   Code Block
   $ git remote set-url --push "push to apache/daffodil disabled"

   
   

8. Create a new branch off of the asf/main branch named daffodil-XYZ-description, where XYZ is the JIRA bug number and -description is an optional, very short description of the bug making it easier to differentiate between multiple development branches. For example:

   Code Block
   language bash
   $ git checkout -b daffodil-123-bitorder-feature asf/main

   
   

9. Make changes to the branch, frequently adding new commits. For example, the following process should repeat until your code is ready to be reviewed:

   Code Block
   edit files $ git add <files that have changed> $ git commit

   Code changes should follow the Daffodil Code Style Guidelines and should add appropriate tests using the Test Data Markup Language (TDML) or unit tests.

   General guidelines for a good commit message:

   - The first line of a commit message should contain a short (~50 characters) description of the changes.

   - The second line should be blank, followed by a longer description of the change, wrapped at 72 characters. This long description should describe what was changed and, more importantly, why those changes were made. The 'what' can be determined by inspecting the code, but the 'why' is often less obvious.

   - If there are any changes that deprecate functionality or are non-backwards compatible, a section should follow labeled with the "Deprecation/Compatibility:" keyword with a description that can be copy/pasted into release notes. This should be more user focused, including what was deprecated/non-backwards compatible and a migration guide.

   - At the end of the commit should be a blank line followed by the JIRA bug number, e.g. DAFFODIL-123. Multiple bugs referenced in a single commit should be separated by a comma on the same line.

   An example of a commit message is:

   Code Block

   Add support for the dfdl:bitOrder feature   Longer explanation of what changes were made to support the bitOrder feature, including a description of why the changes were made. Multiple lines are wrapped at 72 characters. Deprecation/Compatibility: The dfdlx:bitDirection extension property is now deprecated in favor of the new dfdl:bitOrder property: - dfdlx:bitDirection="l2r" becomes dfdl:bitOrder="mostSignificantBitFirst" - dfdlx:bitDirection="r2l" becomes dfdl:bitOrder="leastSignificantBitFirst" DAFFODIL-123

   
   

   Info

   Your IDE or operating system environment may add files to the git repository that are specific to your development environment, such as temporary backups and IDE project files. These files should be ignored and not commited by git. However, because they are specific to your environment, the Daffodil .gitignore file does not contain entires for them. You may want to add such entires to one of the following system-specific gitignore files instead: $GIT_DIR/info/exclude  $XDG_CONFIG_HOME/git/ignore  $HOME/.config/git/ignore  See the gitignore man page for more information.

   
   

10. When changes are complete, rebase your commits onto the latest asf/main and verify that all tests pass:

    Code Block
    language bash
    $ git fetch asf $ git rebase asf/main $ sbt test

    Note that you should not use git pull or git merge to sync to the asf repo. Always fetch/rebase and avoid merge commits. Pull requests containing merge commits will be rejected.

    
    

11. If multiple commits were made in step 8, use git rebase -i asf/main to interactively rebase and squash the commits into the smallest number of logical commits. Most commonly this should be a single commit, but there may be some rare cases where multiple commits make sense.

    
    

12. Push your branch to your fork:

    Code Block
    language bash
    $ git push origin daffodil-123-bitorder-feature

    
    

13. Use the GitHub interface to create a pull request for your new branch.
    
    

14. Wait for review comments. There must be at least two +1's from other committers before the change can be merged. If there are any review comments that require changes or the automated Travis CI build fails, create a new commit on your branch (do not squash your changes yet or use git commit --amend) and push your branch with new commits to GitHub for furthur review. The process should look like:

    Code Block
    edit files $ git add <files that changed> $ git commit $ git push origin daffodil-123-bitorder-feature

    The pull request will automatically update with your new commit. Repeat this step until at least two +1's are recieved from committers.
     

15. Once at least two +1's are received from committers, a committer can accept the pull request. If you made extra commits in step 12, you should now fetch the latest asf, rebase and squash the changes into a single commit  (fixing potential conflicts), and push to origin using the --force option:

    Code Block
    $ git fetch asf $ git rebase -i asf/main $ git push --force origin daffodil-123-bitorder-feature

    
    

16. A committer can now merge the pull request using the GitHub GUI. This is to be done by clicking the "Merge pull request" drop down and selecting "Rebase and merge". The "Create merge commit" and "Squash and merge" options should not be used.  For new committers, you may need to link your GitHub and ASF accounts by visiting https://gitbox.apache.org before you can merge.
     

17. The committer that merged the pull request should now mark the JIRA bug as "Resolved" and add a comment with the git commit hash that includes the fix.
    
    

18. If you would like to clean up, you can now delete your development branch, either via the GitHub user interface or:

    Code Block
    language bash
    $ git push --delete origin daffodil-123-bitorder-feature $ git branch -D daffodil-123-bitorder-feature