What is Markdownlint?

Markdownlint is a static analysis tool designed to enforce consistency and style rules for Markdown files. Markdownlint can include checks for headings, lists, line length, and syntax preferences. It's particularly useful for projects with multiple contributors to ensure that all Markdown documents adhere to a set of standardized guidelines.

Installing Markdownlint

With Trunk Check, you can automatically install and configure Markdownlint along with any relevant linters in a few straightforward steps. Here's how:

First, if you haven't already installed Trunk CLI, you can do so with the command below:

1curl -fsSL | bash

Next, you can initialize Trunk from the root of your git repository:

1trunk init

This command will scan your repository and create a .trunk/trunk.yaml file that enables all linters, formatters, and security analyzers, recommended by Trunk Check. This includes Markdownlint if applicable to your project.

To see all available linters Trunk Check installed, simply run:

1trunk check list

If you find Markdownlint is not automatically enabled, you can do so by running:

1trunk check enable markdownlint

Alternatively, to disable markdownlint run the command below. To disable other tooling applied by Trunk Check, simply replace markdownlint with the respective tool you're looking to disable.

1trunk check disable markdownlint

For more details on Trunk Check setup, see here.

Configuring Markdownlint

Most linters provide some mechanism to tweak their configuration, e.g. .eslintrc or Cargo.toml. Trunk is aware of all the ways individual tools are configured and supports them. This means linters you've already configured will continue to work exactly the same, just now supercharged by Trunk Check.

Like many linters with Trunk, Markdownlint works out of the box so there's no need to set up a custom configuration. If you're interested in other tooling outside of Markdownlint, check out our open-source repository to see how we define and support 90+ linters.

Running Markdownlint

To check your code with Markdownlint, run the command below. This command executes Markdownlint, along with any other linters Trunk Check has enabled on files you've modified. Since Trunk is git-aware, it knows what you've changed, and by adding batched execution and caching, you end up with a much faster and smoother way to run Markdownlint and other tools.

1trunk check

If you prefer to check files you've modified with Markdownlint only, run the following:

1trunk check --filter=markdownlint

Although we'd recommend against it depending on the size of your repository, you can check all files with Markdownlint by running the command below.

1trunk check --all --filter=markdownlint

In most scenarios, you'll want to execute against modified files. Since Trunk is git-aware, it knows what you've changed, and by adding batched execution and caching, you end up with a much faster and smoother way to run Markdownlint and other tools.

Updating Trunk Check & Markdownlint

To upgrade the Trunk CLI along with all plugins and linters in your trunk.yaml simply run:

1trunk upgrade

We highly recommend running on the latest validated versions of tools as updates will frequently include important security fixes and additional valuable checks. Trunk only auto-suggests linter upgrades to versions that we have tested and support, so you may see a slight lag time when a new linter version is released.

Upgrade will also recommend new tools that have become applicable since the last time your repository was scanned. This can be a result of using new technologies in your repository or Trunk itself adding support for more tools. If you don't like a particular recommendation, you can always run trunk check disable <linter> to teach trunk not to recommend it.

Recommended Linters to Pair with Markdownlint

For comprehensive code quality, consider pairing Markdownlint with:

  • Prettier for code formatting.

  • ESLint for JavaScript/TypeScript linting.

  • Stylelint for CSS linting.

These tools complement Markdownlint by covering different aspects of your project's codebase, ensuring overall quality and consistency.