• Overview
• What warrants a changelog entry?
• Writing good changelog entries
• 
  How to generate a changelog entry
  
  
  • History and Reasoning

Changelog entries

This guide contains instructions for when and how to generate a changelog entry
file, as well as information and history about our changelog process.

Overview

Each bullet point, or entry , in our
CHANGELOG.md
file is generated from the subject line of a Git commit. Commits are included
when they contain the Changelog Git trailer.
When generating the changelog, author and merge request details are added
automatically.

The Changelog trailer accepts the following values:

• added
• fixed
• changed
• deprecated
• removed
• security
• performance
• other

An example of a Git commit to include in the changelog is the following:

Update git vendor to gitlab

Now that we are using gitaly to compile git, the git version isn't known
from the manifest, instead we are getting the gitaly version. Update our
vendor field to be `gitlab` to avoid cve matching old versions.

Changelog: changed

GitLab automatically links the merge request to the commit when generating the
changelog. If you want to override the merge request to link to, you can specify
an alternative merge request using the MR trailer:

Update git vendor to gitlab

Now that we are using gitaly to compile git, the git version isn't known
from the manifest, instead we are getting the gitaly version. Update our
vendor field to be `gitlab` to avoid cve matching old versions.

Changelog: changed
MR: https://gitlab.com/foo/bar/-/merge_requests/123

The value must be the full URL of the merge request.

What warrants a changelog entry?

• Any user-facing change should have a changelog entry. Example: “GitLab now
  uses system fonts for all text.”
• A fix for a regression introduced and then fixed in the same release (i.e.,
  fixing a bug introduced during a monthly release candidate) should not
  have a changelog entry.
• Any developer-facing change (e.g., refactoring, technical debt remediation,
  test suite changes) should not have a changelog entry. Example: “Reduce
  database records created during Cycle Analytics model spec.”
• 
  Any contribution from a community member, no matter how small, may have
  a changelog entry regardless of these guidelines if the contributor wants one.
  Example: “Fixed a typo on the search results page. (Jane Smith)”

Writing good changelog entries

A good changelog entry should be descriptive and concise. It should explain the
change to a reader who has zero context about the change. If you have trouble
making it both concise and descriptive, err on the side of descriptive.

• 
  Bad: Go to a project order.
• 
  Good: Show a user’s starred projects at the top of the “Go to project”
  dropdown.

The first example provides no context of where the change was made, or why, or
how it benefits the user.

• 
  Bad: Copy (some text) to clipboard.
• 
  Good: Update the “Copy to clipboard” tooltip to indicate what’s being
  copied.

Again, the first example is too vague and provides no context.

• 
  Bad: Fixes and Improves CSS and HTML problems in mini pipeline graph and
  builds dropdown.
• 
  Good: Fix tooltips and hover states in mini pipeline graph and builds
  dropdown.

The first example is too focused on implementation details. The user doesn’t
care that we changed CSS and HTML, they care about the end result of those
changes.

• 
  Bad: Strip out nil s in the Array of Commit objects returned from
  find_commits_by_message_with_elastic
  
• 
  Good: Fix 500 errors caused by Elasticsearch results referencing
  garbage-collected commits

The first example focuses on how we fixed something, not on what it fixes.
The rewritten version clearly describes the end benefit to the user (fewer 500
errors), and when (searching commits with Elasticsearch).

Use your best judgement and try to put yourself in the mindset of someone
reading the compiled changelog. Does this entry add value? Does it offer context
about where and why the change was made?

How to generate a changelog entry

Git trailers are added when committing your changes. This can be done using your
text editor of choice. Adding the trailer to an existing commit requires either
amending to the commit (if it’s the most recent one), or an interactive rebase
using git rebase -i .

To update the last commit, run the following:

git commit --amend

You can then add the Changelog trailer to the commit message. If you had
already pushed prior commits to your remote branch, you have to force push
the new commit:

git push -f origin your-branch-name

To edit older (or multiple commits), use git rebase -i HEAD~N where N is the
last N number of commits to rebase. Let’s say you have 3 commits on your branch:
A, B, and C. If you want to update commit B, you need to run:

git rebase -i HEAD~2

This starts an interactive rebase session for the last two commits. When
started, Git presents you with a text editor with contents along the lines of
the following:

pick B Subject of commit B
pick C Subject of commit C

To update commit B, change the word pick to reword , then save and quit the
editor. Once closed, Git presents you with a new text editor instance to edit
the commit message of commit B. Add the trailer, then save and quit the editor.
If all went well, commit B is now updated.

For more information about interactive rebases, take a look at
the Git documentation.

History and Reasoning

This method was adopted from the primary GitLab codebase, as we
found the workflow to be appealing and familiar.

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