Source: http://karma-runner.github.io/0.10/dev/git-commit-msg.html

The reasons for these conventions:

automatic generating of the changelog
simple navigation through git history (eg. ignoring style changes)

Format of the commit message:

<type>(<scope>): <subject>
<body>
<footer>

Message subject (first line)

First line cannot be longer than 70 characters, second line is always blank and other lines should be wrapped at 80 characters.

Allowed values:

feat (new feature)
fix (bug fix)
docs (changes to documentation)
style (formatting, missing semi colons, etc; no code change)
refactor (refactoring production code)
test (adding missing tests, refactoring tests; no production code change)
chore (updating grunt tasks etc; no production code change)

Example values:

init
runner
watcher
config
web-server
proxy
etc.

The <scope> can be empty (eg. if the change is a global or difficult to assign to a single component), in which case the parentheses are omitted.

Message body

uses the imperative, present tense: “change” not “changed” nor “changes”
includes motivation for the change and contrasts with previous behavior

For more info about message body, see:

Message footer

Referencing issues Closed issues should be listed on a separate line in the footer prefixed with "Closes" keyword like this:

Closes #234

or in case of multiple issues:

Closes #123, #245, #992

Breaking changes

All breaking changes have to be mentioned in footer with the description of the change, justification and migration notes.

BREAKING CHANGE:

`port-runner` command line option has changed to `runner-port`, so that it is
consistent with the configuration file syntax.

To migrate your project, change all the commands, where you use `--port-runner`
to `--runner-port`.