# Git Commit Guidelines
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**.
## Commit Message Format
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>
```
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.
## Type
Must be one of the following:
* **feat**: A new feature
* **fix**: A bug fix
* **docs**: Documentation only changes
* **style**: Changes that do not affect the meaning of the code (white-space, formatting, missing
semi-colons, etc)
* **refactor**: A code change that neither fixes a bug or adds a feature
* **perf**: A code change that improves performance
* **test**: Adding missing tests
* **chore**: Changes to the build process or auxiliary tools and libraries such as documentation
generation
## Scope
The scope should refer to a module in hyper that is being touched. Examples:
* client
* server
* http1
* http2
* ffi
* upgrade
* examples
## Subject
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
## Body
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.
## Footer
The footer should contain any information about **Breaking Changes** and is also the place to
reference GitHub issues that this commit **Closes**.
The last line of commits introducing breaking changes should be in the form `BREAKING CHANGE: <desc>`
