We have very precise rules over how our git commit messages can be formatted. This leads to more readable messages that are easy to follow when looking through the project history. But also, we use the git commit messages to generate the change log.
Each commit message consists of a header, a body and a footer. The header has a special format that includes a type, a scope and a subject:
<type>(<scope>): <subject>
<BLANK LINE>
<body>
<BLANK LINE>
<footer>
The header is mandatory and the scope of the header is optional.
Any line of the commit message cannot be longer 100 characters! This allows the message to be easier to read on GitHub as well as in various git tools.
Footer should contain a closing reference to an issue if any.
Samples: (even more samples)
docs(changelog): update change log to beta.5
If the commit reverts a previous commit, it should begin with revert:
, followed by the header of the reverted commit. In the body it should say: This reverts commit <hash>.
, where the hash is the SHA of the commit being reverted.
Must be one of the following:
- build: Changes that affect the build system or external dependencies (example scopes: gulp, broccoli, npm)
- chore: Updating tasks etc; no production code change
- ci: Changes to our CI configuration files and scripts (example scopes: Travis, Circle, BrowserStack, 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
- style: Changes that do not affect the meaning of the code (white-space, formatting, missing semi-colons, etc)
- test: Adding missing tests or correcting existing tests
The subject contains succinct description of the change:
- use the imperative, present tense: "change" not "changed" nor "changes"
- don't capitalize first letter
- no dot (.) at the end
Just as in the subject, use the imperative, present tense: "change" not "changed" nor "changes". The body should include the motivation for the change and contrast this with previous behavior.
The footer should contain any information about Breaking Changes and is also the place to reference GitHub issues that this commit Closes.
Breaking Changes should start with the word BREAKING CHANGE:
with a space or two newlines. The rest of the commit message is then used for this.