Writing a Good Changelog Entry — Templates

You’ve shipped a new feature, squashed a gnarly bug, or refactored a critical service. Congratulations! But now comes the often-overlooked, sometimes dreaded, final step: documenting that change for your users and internal stakeholders. If you’re like many engineering teams, this might involve manually compiling release notes, which is tedious, error-prone, and often left to the last minute.

This is where Shipnote comes in, transforming your git commits and merged PRs into user-friendly changelogs automatically. But even the smartest automation needs good input. The quality of your auto-generated changelog directly correlates with the quality and consistency of your source material: your commit messages and Pull Request (PR) descriptions.

So, how do you ensure that every contribution, no matter how small, contributes to a clear, comprehensive, and consistent changelog? The answer often lies in adopting a templated approach.

The Core Problem: Inconsistent Commits

Engineers are problem-solvers. We're focused on shipping code, not necessarily on crafting prose. This often leads to commit messages and PR descriptions that are:

  • Vague: "updates," "fix bug," "refactor." What was updated? Which bug? What was refactored, and why?
  • Inconsistent: One team member uses present tense, another past. One includes context, another just a title.
  • Incomplete: Missing critical information like breaking changes, performance implications, or how to verify the change.
  • Internal-focused: Full of jargon or references only understood by the immediate team, not external users or other departments.

Without a structured approach, Shipnote (or any changelog tool) has to work harder to extract meaning, and its output might reflect that inconsistency.

Why Templates?

Templates aren't about stifling creativity; they're about channeling it effectively. For changelog entries, templates provide:

  • Consistency: Everyone follows the same structure, making changelogs predictable and easy to read.
  • Clarity: Prompts guide you to include essential information, reducing ambiguity.
  • Completeness: Ensures critical details like breaking changes, performance impacts, or security fixes aren't missed.
  • Reduced Mental Overhead: You don't have to re-invent the wheel for every commit or PR. Just fill in the blanks.
  • Improved Automation: Tools like Shipnote thrive on structured data. Consistent templates make our job of generating accurate changelogs much easier and more reliable.

Anatomy of a Good Changelog Entry (and thus a Good Template)

Before diving into how to implement templates, let's define what makes a changelog entry valuable. A good entry typically includes:

  • Type: Categorizes the change. This is crucial for filtering and understanding impact. Common types (often from Conventional Commits) include:
    • feat: A new feature or enhancement.
    • fix: A bug fix.
    • docs: Documentation changes.
    • style: Formatting, missing semicolons, etc.; no code change.
    • refactor: A code change that neither fixes a bug nor adds a feature.
    • perf: A code change that improves performance.
    • test: Adding missing tests or correcting existing tests.
    • build: Changes that affect the build system or external dependencies (e.g., gulp, broccoli, npm).
    • ci: Changes to CI configuration files and scripts (e.g., Travis, Circle, GitLab CI).
    • chore: Other changes that don't modify src or test files.
    • revert: Reverts a previous commit.
  • Scope (Optional but recommended): Specifies the part of the codebase affected. E.g., api, ui, auth, database, payments. This helps users quickly see if a change is relevant to their area of interest.
  • Subject: A concise, imperative summary of the change, ideally under 50-70 characters. It should complete the sentence "If merged, this commit will..."
    • Good: feat(auth): Add multi-factor authentication support
    • Bad: Fixed issue
  • Body (Optional but powerful): A more detailed explanation of the change.
    • Motivation: Why was this change needed? What problem does it solve?
    • Implementation details: Briefly explain the "how."
    • Impact: What are the consequences of this change?
    • Verification: How can someone confirm this change works as expected?
  • Breaking Changes: Clearly flag any changes that require users to update their code, configuration, or workflow. This is often denoted with BREAKING CHANGE: in the body.
  • References: Link to related issues, tickets (e.g., Fixes #123, Closes JIRA-456), or PRs.

Template Approaches & Examples

Let's look at practical ways to implement these structures.

Approach 1: Commit Message Templates (Git Hooks)

You can enforce (or at least suggest) a commit message format using a local Git hook. The prepare-commit-msg hook is ideal for this, as it runs before the commit message editor opens.

Example: .git/hooks/prepare-commit-msg

#!/bin/sh
COMMIT_MSG_FILE=$1
COMMIT_SOURCE=$2
SHA1=$3

# Only apply template if it's a new commit (not a merge, squash, amend, etc.)
if [ "$COMMIT_SOURCE" = "" ]; then
  cat << EOF > "$COMMIT_MSG_FILE"
<type>(<scope>): <subject>

<body>

BREAKING CHANGE: <description if any>

Refs: #<issue-number>, JIRA-<ticket-id>
EOF
fi

To use this: 1. Save the above script as prepare-commit-msg in your project's .git/hooks/ directory. 2. Make it executable: chmod +x .git/hooks/prepare-commit-msg.

Now, when you run git commit, your editor will open with this template pre-filled.

Pros: * Immediate guidance for individual commits. * Local to each developer, so easy to experiment.

Cons: * Not enforced globally across the team or repository. Developers can easily delete the template content. * Requires manual setup for each developer. * Less effective if you predominantly use squash merges, as the PR description often becomes the commit message.

Approach 2: Pull Request Description Templates

This is often the most effective approach for teams using PR workflows, especially when using tools like Shipnote. Many platforms (GitHub, GitLab, Bitbucket) support PR templates. When a new PR is created, the template automatically populates the description field.

Example: .github/PULL_REQUEST_TEMPLATE.md (for GitHub)

## Type of change

Please delete options that are not relevant.

- [ ] Bug fix (non-breaking change which fixes an issue)
- [ ] New feature (non-breaking change which adds functionality)
- [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
- [ ] This change requires a documentation update

## Description

Please include a summary of the change and which issue is fixed/feature is added. Please also include relevant motivation and context. List any dependencies that are required for this change.

Fixes # (issue)

## How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Provide instructions so we can reproduce. Please also list any relevant details for your test configuration.

- [ ] Test A
- [ ] Test B

**Test Configuration**:
* Firmware version:
* Hardware:
* Toolchain:

## Checklist:

- [ ] My code follows the style guidelines of this project
- [ ] I have performed a self-review of my own code
- [ ] I have commented my code, particularly in hard-to-understand areas
- [ ] I have made corresponding changes to the documentation
- [ ] My changes generate no new warnings
- [ ] I have added tests that prove my fix is effective or that my feature works
- [ ] New and existing unit tests pass locally with my changes
- [ ] Any dependent changes have been merged and published in downstream modules

To use this: 1. Create a .github/ folder (or .gitlab/ for GitLab, pull_request_templates/ for Bitbucket) in your repository's root. 2. Save the content as PULL_REQUEST_TEMPLATE.md inside that folder.

Pros: * Enforced at the PR level, visible to