Commit Message Format

We have very precise rules over how our Git commit messages must be formatted. This format leads to easier to read commit history and makes it analyzable for changelog generation.

Each commit message consists of a header, a body, and a footer.

<header>
<BLANK LINE>
<body>
<BLANK LINE>
<footer>

The header is mandatory and must conform to the Commit Message Header format.

The body is mandatory for all commits except for those of type "docs". When the body is present it must be at least 20 characters long and must conform to the Commit Message Body format.

The footer is optional. The Commit Message Footer format describes what the footer is used for and the structure it must have.

Commit Message Header

<type>(<scope>): <short summary>
  │       │             │
  │       │             └─⫸ Summary in present tense. Not capitalized. No period at the end.
  │       │
  │       └─⫸ Commit Scope: animations|bazel|benchpress|common|compiler|compiler-cli|core|
  │                          elements|forms|http|language-service|localize|platform-browser|
  │                          platform-browser-dynamic|platform-server|router|service-worker|
  │                          upgrade|zone.js|packaging|changelog|docs-infra|migrations|
  │                          devtools
  │
  └─⫸ Commit Type: build|ci|docs|feat|fix|perf|refactor|test

The <type> and <summary> fields are mandatory, the (<scope>) field is optional.

Type

Must be one of the following:

Type	Description
build	Changes that affect the build system or external dependencies (example scopes: gulp, broccoli, npm)
ci	Changes to our CI configuration files and scripts (examples: Github Actions, SauceLabs)
docs	Documentation only changes
feat	A new feature
fix	A bug fix
perf	A code change that improves performance
refactor	A code change that neither fixes a bug nor adds a feature
test	Adding missing tests or correcting existing tests

Scope

The scope should be the name of the npm package affected (as perceived by the person reading the changelog generated from commit messages).

The following is the list of supported scopes:

animations
bazel
benchpress
changelog
common
compiler
compiler-cli
core
dev-infra
devtools
docs-infra
elements
forms
http
language-service
localize
migrations
packaging
platform-browser
platform-browser-dynamic
platform-server
router
service-worker
upgrade
zone.js

There are currently a few exceptions to the "use package name" rule:

packaging: used for changes that change the npm package layout in all of our packages, e.g. public path changes, package.json changes done to all packages, d.ts file/format changes, changes to bundles, etc.
changelog: used for updating the release notes in CHANGELOG.md
dev-infra: used for dev-infra related changes within the directories /scripts and /tools
docs-infra: used for docs-app (angular.dev) related changes within the /adev directory of the repo
migrations: used for changes to the ng update migrations.
devtools: used for changes in the browser extension.
none/empty string: useful for test and refactor changes that are done across all packages (e.g. test: add missing unit tests) and for docs changes that are not related to a specific package (e.g. docs: fix typo in tutorial).

Summary

Use the summary field to provide a succinct description of the change:

use the imperative, present tense: "change" not "changed" nor "changes"
don't capitalize the first letter
no dot (.) at the end

Commit Message Body

Just as in the summary, use the imperative, present tense: "fix" not "fixed" nor "fixes".

Explain the motivation for the change in the commit message body. This commit message should explain why you are making the change. You can include a comparison of the previous behavior with the new behavior in order to illustrate the impact of the change.

Commit Message Footer

The footer can contain information about breaking changes and deprecations and is also the place to reference GitHub issues and other PRs that this commit closes or is related to. For example:

BREAKING CHANGE: <breaking change summary>
<BLANK LINE>
<breaking change description + migration instructions>
<BLANK LINE>
<BLANK LINE>
Fixes #<issue number>

or

DEPRECATED: <what is deprecated>
<BLANK LINE>
<deprecation description + recommended update path>
<BLANK LINE>
<BLANK LINE>
Closes #<pr number>

Breaking Change section should start with the phrase BREAKING CHANGE: followed by a brief summary of the breaking change, a blank line, and a detailed description of the breaking change that also includes migration instructions.

Similarly, a Deprecation section should start with DEPRECATED: followed by a short description of what is deprecated, a blank line, and a detailed description of the deprecation that also mentions the recommended update path.

Revert commits

If the commit reverts a previous commit, it should begin with revert: , followed by the header of the reverted commit.

The content of the commit message body should contain:

information about the SHA of the commit being reverted in the following format: This reverts commit <SHA>,
a clear description of the reason for reverting the commit message.