index.js

/**
 * @fileoverview Enables the processor for Markdown file extensions.
 * @author Brandon Mills
 */

//-----------------------------------------------------------------------------
// Imports
//-----------------------------------------------------------------------------

import { processor } from "./processor.js";
import { MarkdownLanguage } from "./language/markdown-language.js";
import recommendedRules from "./build/recommended-config.js";
import rules from "./build/rules.js";

//-----------------------------------------------------------------------------
// Type Definitions
//-----------------------------------------------------------------------------

/** @typedef {import("eslint").Linter.RulesRecord} RulesRecord*/
/** @typedef {import("eslint").Linter.Config} Config*/
/** @typedef {import("eslint").ESLint.Plugin} Plugin */
/** @typedef {import("eslint").Rule.RuleModule} RuleModule */
/** @typedef {import("@eslint/core").Language} Language */

//-----------------------------------------------------------------------------
// Exports
//-----------------------------------------------------------------------------

/** @type {RulesRecord} */
const processorRulesConfig = {
	// The Markdown parser automatically trims trailing
	// newlines from code blocks.
	"eol-last": "off",

	// In code snippets and examples, these rules are often
	// counterproductive to clarity and brevity.
	"no-undef": "off",
	"no-unused-expressions": "off",
	"no-unused-vars": "off",
	"padded-blocks": "off",

	// Adding a "use strict" directive at the top of every
	// code block is tedious and distracting. The config
	// opts into strict mode parsing without the directive.
	strict: "off",

	// The processor will not receive a Unicode Byte Order
	// Mark from the Markdown parser.
	"unicode-bom": "off",
};

/** @type {Plugin & { languages: Record<string,Language>}} */
const plugin = {
	meta: {
		name: "@eslint/markdown",
		version: "6.2.1", // x-release-please-version
	},
	processors: {
		markdown: processor,
	},
	languages: {
		commonmark: new MarkdownLanguage({ mode: "commonmark" }),
		gfm: new MarkdownLanguage({ mode: "gfm" }),
	},
	rules,
	configs: {
		"recommended-legacy": {
			plugins: ["markdown"],
			overrides: [
				{
					files: ["*.md"],
					processor: "markdown/markdown",
				},
				{
					files: ["**/*.md/**"],
					parserOptions: {
						ecmaFeatures: {
							// Adding a "use strict" directive at the top of
							// every code block is tedious and distracting, so
							// opt into strict mode parsing without the
							// directive.
							impliedStrict: true,
						},
					},
					rules: {
						...processorRulesConfig,
					},
				},
			],
		},
	},
};

plugin.configs.recommended = [
	/** @type {Config & {language:string}} */
	({
		name: "markdown/recommended",
		files: ["**/*.md"],
		language: "markdown/commonmark",
		plugins: {
			markdown: plugin,
		},
		rules: /** @type {RulesRecord} */ (recommendedRules),
	}),
];

plugin.configs.processor = [
	{
		name: "markdown/recommended/plugin",
		plugins: {
			markdown: plugin,
		},
	},
	{
		name: "markdown/recommended/processor",
		files: ["**/*.md"],
		processor: "markdown/markdown",
	},
	{
		name: "markdown/recommended/code-blocks",
		files: ["**/*.md/**"],
		languageOptions: {
			parserOptions: {
				ecmaFeatures: {
					// Adding a "use strict" directive at the top of
					// every code block is tedious and distracting, so
					// opt into strict mode parsing without the
					// directive.
					impliedStrict: true,
				},
			},
		},
		rules: {
			...processorRulesConfig,
		},
	},
];

export default plugin;