Commitlint is useful to enforce a particular commit message style. This prevents developers from unspecific commit messages like

git commit -m "update"

Using a commitlint pre-commit hook ensures that commit messages are checked on git commit to see if they comply with Angular commit style required for commit parsing by semantic-release version. By ensuring angular commit messages, we can use semantic-release version to automatically bump your python package version and update the changelog file.

Summary

  1. poetry add commitlint --group dev - Install commitlint python library and add to tool.poetry.group.dev.dependencies in pyproject.toml.
  2. Configure commitlint by creating a commitlint.config.js file - see procedure for details.
  3. Add commitlint hook to .pre-commit-config.yaml - see procedure for details.
  4. pre-commit install - Install pre-commit hooks in .git folder.
  5. pre-commit autoupdate - Check for and install any updates to pre-commit hooks.
  6. Example commits using commitlint - see procedure for details.

Procedure

Install commitlint

Install commitlint python library. Using poetry for dependency management allows us to install commitlint and add it to the dependency list in pyproject.toml with the command below. By amending --group dev, we can add it to the tool.poetry.dev.dependencies list used for development, which allows them to only be installed when required.

poetry add commitlint --group dev

Configure commitlint

Set commitlint to use Angular style by creating a new file .commitlintrc in your project root directory with the following contents:

{
    "extends": [
        "@commitlint/config-angular"
    ]
}

Alternatively, use to configure commitlint with contents below to configure commitlint.

//comitling.config.js at the root of your repo
module.exports = {
    extends: ['@commitlint/config-angular'], // => commitlint/config-angular
};

Note: it was not possible to configure commitlint with a commitlintrc.yaml.

Add pre-commit hook

Next, add a pre-commit hook for commitlint in a .pre-commit-config.yaml file in your project root directory. You can have multiple hooks below the “repos:” line.

repos:
# commitlint
- repo: https://github.com/alessandrojcm/commitlint-pre-commit-hook
  rev: 'v9.13.0'
  hooks:
      - id: commitlint
        stages: [commit-msg]
        additional_dependencies: ['@commitlint/config-angular']

Install pre-commit hook

Install pre-commit hooks in .git folder of your project root directory.

pre-commit install

Update pre-commit hook

Check for and install updates to the pre-commit hooks.

pre-commit autoupdate

Using commitlint

Now, committing some code will required commit messages in Angular style, e.g.

git commit -m “feat: added button”

Longer commit messages comprise a title (limited to 72 characters) and a body separated by a blank line. These can be written using two -m where the first is for the message title and the second is for the message body. For example:

git commit -m "test: demonstrate multi-line commit message" -m "

After a blank line enter the message body. Press ENTER before closing the quotes to add a line break. Then close the quotes and hit ENTER twice to apply the commit.
"

The type of the commit must be one of set of allowed types allowed in Angular commit style.

References