Markdown Plugin

Rules for linting .md files containing Markdown, the lightweight markup language.
This plugin comes packaged with the flint npm package.

Presets

Flint’s Markdown plugin provides the following presets:

Preset	Recommended	Description
logical	✅ Always	Common rules for finding bugs and enforcing good logical practices in Markdown files.
logicalStrict	☑️ When Ready	Additional rules for finding bugs and enforcing good logical practices in Markdown files.
stylistic	✅ Always	Common rules for consistent styling and best stylistic practices in Markdown files.
stylisticStrict	☑️ When Ready	Additional rules for consistent styling and best stylistic practices in Markdown files.

If you are just getting started with linting, Flint recommends using the logical and stylistic presets:

flint.config.ts

import { defineConfig, md } from "flint";

export default defineConfig({
  use: [
    {
      files: md.files.all,
      rules: [md.presets.logical, md.presets.stylistic],
    },
  ],
});

If you are experienced with both Markdown and linting, Flint recommends using the logicalStrict and stylisticStrict presets:

flint.config.ts

import { defineConfig, md } from "flint";

export default defineConfig({
  use: [
    {
      files: md.files.all,
      rules: [md.presets.logicalStrict, md.presets.stylisticStrict],
    },
  ],
});

Note

Coming soon: more expansive documentation on choosing and combining plugins & presets with Flint.

logical

Rules that find bugs and enforce good Markdown practices for most-to-all Markdown files.

flint.config.ts

import { defineConfig, md } from "flint";

export default defineConfig({
  use: [
    {
      files: md.files.all,
      rules: md.presets.logical,
    },
  ],
});

logicalStrict

Additional logical rules that enforce best practices which are not always straightforward to implement. These rules are recommended for projects where a majority of developers are experienced with both Markdown and using a linter.

flint.config.ts

import { defineConfig, md } from "flint";

export default defineConfig({
  use: [
    {
      files: md.files.all,
      rules: md.presets.logicalStrict,
    },
  ],
});

This preset’s rules are a superset of those in logical.

stylistic

Rules that enforce consistent styling and best stylistic practices for most-to-all Markdown files.

flint.config.ts

import { defineConfig, md } from "flint";

export default defineConfig({
  use: [
    {
      files: md.files.all,
      rules: md.presets.stylistic,
    },
  ],
});

stylisticStrict

Additional stylistic rules that enforce best practices which are not always straightforward to implement. These rules are recommended for projects where a majority of developers are experienced with both Markdown and using a linter.

flint.config.ts

import { defineConfig, md } from "flint";

export default defineConfig({
  use: [
    {
      files: md.files.all,
      rules: md.presets.stylisticStrict,
    },
  ],
});

This preset’s rules are a superset of those in stylistic.

Rules

Implemented: 16 of 24 (66.6%)

Flint Rule	Preset
definitionContentsReports definitions with empty URLs or only empty fragments.	logical
definitionDuplicatesReports duplicate definition identifiers (case-insensitive).	logical
definitionUsesReports unused reference definitions.	logical
headingIncrementsReports heading levels incrementing by more than one.	logical
imageAltTextsReports images without alternative text.	logical
imageContentsReports images with empty URLs or only empty fragments.	logical
labelReferencesReports missing label references.	logical
labelReferenceValidityReports invalid label references with whitespace.	logical
linkContentsReports links with empty URLs or only empty fragments.	logical
linkFragmentsReports link fragments that don't exist in the document.	logical
referenceLikeUrlsReports resource links/images with URLs that match definition identifiers.	logical
tableColumnCountsReports table rows with column counts that don't match the header.	logical
headingRootDuplicatesReports multiple H1 headings in the same document.	logical (strict)
headingRootPresence	logical (strict)
linkDescriptions	logical (strict)
codeSpaces	stylistic
mediaSyntaxReversalsReports reversed link and image syntax in Markdown.	stylistic
bareUrlsReports bare URLs that should be formatted as autolinks or links.	stylistic (strict)
blockquoteBlankLineMultiples	stylistic (strict)
fencedCodeLanguagesReports fenced code blocks without a language specified.	stylistic (strict)
headingDuplicates	stylistic (strict)
headingEmphasisEquivalents	stylistic (strict)
headingTrailingPunctuation	stylistic (strict)
olPrefixes	stylistic (strict)

Selectors

Flint’s Markdown plugin provides the following file selector:

• all: **/*.md