Flinter

A GitHub Action that lints the frontmatter of markdown files. Write your own rules in js or just stick with the defaults for a quick and easy solution.

Build locally

1. Install packages

yarn install

2. Build with ncc

yarn build

Currently, as this is built using TS we need to run yarn build before pushing.

Getting Started

To use this GitHub action, you'll need to create a .flinter/config.json file. See the below table for information. (Scroll a bit further for an example config.json)

Defaults

Put these fields inside a defaults section

Field	Type	Required	Information
markdownFileExtensions	Array	✅	A list of markdown file extensions to lint against
frontmatter	Array	✅	A list of all fields to lint. If you add directories these fields won't be checked. See below for more information on the frontmatter object.
directories	Array	❌	If you have a specific directories where you only want to lint against those specific markdown files.

Frontmatter Object

Field	Type	Required	Information
field	String	✅	The name of the frontmatter field to lint
required	Boolean	❌	If true, will return an error if the value is null
type	String	❌	TODO: Implement basic type checking
rule	String	❌	name of the custom rule to run. e.g. "custom.js"

Writing custom rules

To write custom rules.

1. Create a new folder ./flinter/linters/
2. Create a .js file and export an async function called run. See the template below.
3. Return a FlinterResult [Boolean,String]
4. Add the file name to the Frontmatter field's rule.

// This must return a boolean value.

/**
 * @param {{field: string, value?: string}} params
 * @returns {{result: boolean, error?: string}}
 */
export async function run(params) {
  return {
    result: true,
  };
}

Example Config.json

{
  "defaults": {
    "markdownFileExtensions": ["md", "mdx"],
    "frontmatter": [
      {
        "field": "title",
        "type": "text",
        "required": true
      }
    ]
  },
  "rules": {
    "frontmatter": [
      {
        "field": "title",
        "type": "text",
        "required": true,
        "rule": "title.js"
      },
      {
        "field": "authors",
        "type": "object",
        "rule": "authors.js"
      }
    ]
  }
}

Note
To enable debug logging, set DEBUG to true where the Flinter action is used
e.g.

    steps:
      - name: Flinter.md
        uses: JackDevAU/[email protected]
        with:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
          DEBUG: true

Acknowledgements

This builds on from the awesome work over @ lint-md-fm.