Breaking: use ESM and drop Node.js < 14

CommonJS modules can no longer `require('hallmark')`. They must use
ESM themselves, or a dynamic `import()`. For further guidance please
see https://gist.github.com/sindresorhus/a39789f98801d908bbc7ff3ecc99d99c

As for the `hallmark` CLI: in Node.js versions older than 14 it is
now a noop.

Needed for #80.
Depends on tape-testing/tape#571

.github/workflows/test.yml

@@ -7,7 +7,7 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-latest, macos-latest, windows-latest]
-        node: [10, 12, 14, 16]
+        node: [14, 16]
     runs-on: ${{ matrix.os }}
     name: ${{ matrix.os }} / Node ${{ matrix.node }}
     steps:

cli.js

@@ -1,12 +1,10 @@
 #!/usr/bin/env node
-'use strict'
 
-if (process.version.match(/^v(\d+)\./)[1] < 10) {
-  console.error('hallmark: Node 10 or greater is required. `hallmark` did not run.')
-  process.exit(0)
-}
+import subarg from 'subarg'
+import fs from 'node:fs'
+import * as hallmark from './index.js'
 
-const argv = require('subarg')(process.argv.slice(2), {
+const argv = subarg(process.argv.slice(2), {
   boolean: ['fix', 'help', 'version', 'commits'],
   string: ['report'],
   default: {
@@ -25,16 +23,17 @@ const argv = require('subarg')(process.argv.slice(2), {
 if (argv.help) {
   usage(0)
 } else if (argv.version) {
-  console.log(require('./package.json').version)
+  const fp = new URL('./package.json', import.meta.url)
+  console.log(JSON.parse(fs.readFileSync(fp, 'utf8')).version)
 } else {
   const { commits, _: rest, ...options } = argv
 
   if (rest[0] === 'lint') {
     options.files = files(rest.slice(1))
-    require('./index.js').lint(options, done)
+    hallmark.lint(options, done)
   } else if (rest[0] === 'fix') {
     options.files = files(rest.slice(1))
-    require('./index.js').fix(options, done)
+    hallmark.fix(options, done)
   } else if (rest[0] === 'bump') {
     console.error("Error: the 'bump' command has been renamed to 'cc add'.\n")
     usage(1)
@@ -43,7 +42,7 @@ if (argv.help) {
       const target = rest[2]
       if (!target) usage(1)
       options.files = files(rest.slice(3))
-      require('./index.js').cc.add(target, { ...options, commits }, done)
+      hallmark.cc.add(target, { ...options, commits }, done)
     } else {
       console.error('Error: unknown command.')
       usage(1)
@@ -52,7 +51,7 @@ if (argv.help) {
     // Old usage (no commands)
     // TODO: deprecate?
     options.files = files(rest)
-    require('./index.js')[options.fix ? 'fix' : 'lint'](options, done)
+    hallmark[options.fix ? 'fix' : 'lint'](options, done)
   }
 }
 
@@ -66,9 +65,8 @@ function done (err, result) {
 }
 
 function usage (exitCode) {
-  const fs = require('fs')
-  const path = require('path')
-  const usage = fs.readFileSync(path.join(__dirname, 'USAGE'), 'utf8').trim()
+  const fp = new URL('./USAGE', import.meta.url)
+  const usage = fs.readFileSync(fp, 'utf8').trim()
 
   if (exitCode) {
     console.error(usage)

compat/cli.cjs

@@ -0,0 +1,12 @@
+#!/usr/bin/env node
+'use strict'
+
+// Must be CommonJS to support Node.js < 12.20
+if (process.version.match(/^v(\d+)\./)[1] < 14) {
+  // Return silently to support hallmark in 'npm test'
+  console.error('Skipping hallmark: Node 14 or greater is required.')
+  process.exit(0)
+}
+
+// Wrapped again to avoid 'Unexpected token import'
+require('./import-cli.cjs')

compat/import-cli.cjs

@@ -0,0 +1,6 @@
+'use strict'
+
+import('../cli.js').catch(function (err) {
+  console.error(err)
+  process.exit(1)
+})

index.js

@@ -1,14 +1,19 @@
-'use strict'
-
-const deglob = require('deglob')
-const find = require('find-file-up')
-const Githost = require('find-githost')
-const engine = require('unified-engine')
-const color = require('supports-color').stdout
-const fromCallback = require('catering').fromCallback
-const processor = require('remark')
-const path = require('path')
-const fs = require('fs')
+import deglob from 'deglob'
+import find from 'find-file-up'
+import Githost from 'find-githost'
+import engine from 'unified-engine'
+import { stdout as color } from 'supports-color'
+import { fromCallback } from 'catering'
+import defaultReporter from 'vfile-reporter-shiny'
+import processor from 'remark'
+import remarkCommonChangelog from 'remark-common-changelog'
+import remarkGithub from 'remark-github'
+import remarkAutolinkReferences from 'remark-autolink-references'
+import remarkToc from 'remark-toc'
+import remarkCollapse from 'remark-collapse'
+import path from 'node:path'
+import fs from 'node:fs'
+import linter from './lint.js'
 
 const kPromise = Symbol('promise')
 
@@ -46,7 +51,7 @@ function hallmark (options, callback) {
         reporter = reporter._[0]
       }
     } else {
-      reporter = require('vfile-reporter-shiny')
+      reporter = defaultReporter
     }
 
     const paddedTable = rc.paddedTable !== false
@@ -73,23 +78,23 @@ function hallmark (options, callback) {
       reporter,
       reporterOptions,
       plugins: [
-        [require('remark-common-changelog'), { cwd, fix, pkg, repository, ...changelog }],
-        [require('remark-github'), { repository }],
+        [remarkCommonChangelog, { cwd, fix, pkg, repository, ...changelog }],
+        [remarkGithub, { repository }],
 
         // Does nothing unless configured
         rc.autolinkReferences
-          ? [require('remark-autolink-references'), {
+          ? [remarkAutolinkReferences, {
               ...rc.autolinkReferences,
               fix
             }]
           : null,
 
         // TODO: https://github.com/vweevers/hallmark/issues/36
-        toc ? [require('remark-toc'), { tight: true }] : null,
-        toc ? [require('remark-collapse'), collapseToc()] : null,
+        toc ? [remarkToc, { tight: true }] : null,
+        toc ? [remarkCollapse, collapseToc()] : null,
 
         fix ? fixers : null,
-        require('./lint.js')({ fix, repository, paddedTable, validateLinks }),
+        linter({ fix, repository, paddedTable, validateLinks }),
         plugins
       ].filter(Boolean),
       settings: {
@@ -121,7 +126,7 @@ function hallmark (options, callback) {
   return callback[kPromise]
 }
 
-exports.lint = function (options, callback) {
+export function lint (options, callback) {
   if (typeof options === 'function') {
     callback = options
     options = {}
@@ -130,7 +135,7 @@ exports.lint = function (options, callback) {
   return hallmark({ ...options, fix: false }, callback)
 }
 
-exports.fix = function (options, callback) {
+export function fix (options, callback) {
   if (typeof options === 'function') {
     callback = options
     options = {}
@@ -139,28 +144,29 @@ exports.fix = function (options, callback) {
   return hallmark({ ...options, fix: true }, callback)
 }
 
-exports.cc = {}
-exports.cc.add = function (target, options, callback) {
-  if (!target) {
-    throw new TypeError('First argument "target" is required')
-  } else if (typeof target !== 'string') {
-    throw new TypeError('First argument "target" must be a string')
-  }
+export const cc = {
+  add: function (target, options, callback) {
+    if (!target) {
+      throw new TypeError('First argument "target" is required')
+    } else if (typeof target !== 'string') {
+      throw new TypeError('First argument "target" must be a string')
+    }
 
-  if (typeof options === 'function') {
-    callback = options
-    options = {}
-  } else if (options == null) {
-    options = {}
-  }
+    if (typeof options === 'function') {
+      callback = options
+      options = {}
+    } else if (options == null) {
+      options = {}
+    }
 
-  const changelog = {
-    commits: options.commits !== false,
-    ...options.changelog,
-    add: target
-  }
+    const changelog = {
+      commits: options.commits !== false,
+      ...options.changelog,
+      add: target
+    }
 
-  return hallmark({ ...options, changelog, fix: true }, callback)
+    return hallmark({ ...options, changelog, fix: true }, callback)
+  }
 }
 
 function read (file, cwd) {

lint.js

@@ -1,15 +1,37 @@
-module.exports = function ({ fix, repository, paddedTable, validateLinks }) {
+import remarkLint from 'remark-lint'
+import remarkLintNoUndefinedReferences from 'remark-lint-no-undefined-references'
+import remarkLintNoUnusedDefinitions from 'remark-lint-no-unused-definitions'
+import remarkLintNoDuplicateDefinitions from 'remark-lint-no-duplicate-definitions'
+import remarkLintNoInlinePadding from 'remark-lint-no-inline-padding'
+import remarkLintBlockquoteIndentation from 'remark-lint-blockquote-indentation'
+import remarkLintCheckboxContentIndent from 'remark-lint-checkbox-content-indent'
+import remarkLintFinalNewline from 'remark-lint-final-newline'
+import remarkLintListItemBulletIndent from 'remark-lint-list-item-bullet-indent'
+import remarkLintListItemIndent from 'remark-lint-list-item-indent'
+import remarkLintNoAutoLinkWithoutProtocol from 'remark-lint-no-auto-link-without-protocol'
+import remarkLintNoBlockquoteWithoutMarker from 'remark-lint-no-blockquote-without-marker'
+import remarkLintNoLiteralUrls from 'remark-lint-no-literal-urls'
+import remarkLintNoHeadingContentIndent from 'remark-lint-no-heading-content-indent'
+import remarkLintHardBreakSpaces from 'remark-lint-hard-break-spaces'
+import remarkLintCodeBlockStyle from 'remark-lint-code-block-style'
+import remarkLintTableCellPadding from 'remark-lint-table-cell-padding'
+import remarkLintTablePipes from 'remark-lint-table-pipes'
+import remarkLintCheckboxCharacterStyle from 'remark-lint-checkbox-character-style'
+import remarkLintDefinitionCase from 'remark-lint-definition-case'
+import remarkValidateLinks from 'remark-validate-links'
+
+export default function ({ fix, repository, paddedTable, validateLinks }) {
   const preset = {
     plugins: [
-      require('remark-lint'),
+      remarkLint,
 
       // These are not automatically fixed by remark-stringify
-      require('remark-lint-no-undefined-references'),
-      require('remark-lint-no-unused-definitions'),
-      require('remark-lint-no-duplicate-definitions'),
-      require('remark-lint-no-inline-padding'),
-      [require('remark-lint-blockquote-indentation'), 2], // Means 1 space.
-      require('remark-lint-checkbox-content-indent')
+      remarkLintNoUndefinedReferences,
+      remarkLintNoUnusedDefinitions,
+      remarkLintNoDuplicateDefinitions,
+      remarkLintNoInlinePadding,
+      [remarkLintBlockquoteIndentation, 2], // Means 1 space.
+      remarkLintCheckboxContentIndent
 
       // TBD
       // require('remark-lint-no-shortcut-reference-image'),
@@ -19,32 +41,32 @@ module.exports = function ({ fix, repository, paddedTable, validateLinks }) {
 
   if (!fix) {
     preset.plugins.push(
-      require('remark-lint-final-newline'),
-      require('remark-lint-list-item-bullet-indent'),
-      [require('remark-lint-list-item-indent'), 'space'],
-      require('remark-lint-no-auto-link-without-protocol'),
-      require('remark-lint-no-blockquote-without-marker'),
-      require('remark-lint-no-literal-urls'),
-      require('remark-lint-no-heading-content-indent'),
-      require('remark-lint-hard-break-spaces'),
-      [require('remark-lint-code-block-style'), 'fenced'],
+      remarkLintFinalNewline,
+      remarkLintListItemBulletIndent,
+      [remarkLintListItemIndent, 'space'],
+      remarkLintNoAutoLinkWithoutProtocol,
+      remarkLintNoBlockquoteWithoutMarker,
+      remarkLintNoLiteralUrls,
+      remarkLintNoHeadingContentIndent,
+      remarkLintHardBreakSpaces,
+      [remarkLintCodeBlockStyle, 'fenced'],
 
       // TODO: support fixed-width columns (https://github.com/remarkjs/remark-lint/issues/217)
-      paddedTable ? [require('remark-lint-table-cell-padding'), 'padded'] : null,
+      paddedTable ? [remarkLintTableCellPadding, 'padded'] : null,
 
-      require('remark-lint-table-pipes'),
-      [require('remark-lint-checkbox-character-style'), {
+      remarkLintTablePipes,
+      [remarkLintCheckboxCharacterStyle, {
         checked: 'x', unchecked: ' '
       }],
-      require('remark-lint-definition-case')
+      remarkLintDefinitionCase
     )
   }
 
   // Temporarily allow skipping link validation, because remark does not parse
   // HTML anchors - as used in various Level readme's. Those readme's should be
   // updated to use markdown only.
   if (validateLinks) {
-    preset.plugins.push([require('remark-validate-links'), {
+    preset.plugins.push([remarkValidateLinks, {
       // If we don't pass this, remark-validate-links tries to get the repo url
       // from `git remote -v` which is not desirable for forks.
       repository: repository || false

package.json

@@ -4,16 +4,18 @@
   "description": "Markdown Style Guide, with linter and automatic fixer",
   "author": "Vincent Weevers",
   "license": "GPL-3.0",
-  "bin": "cli.js",
-  "main": "index.js",
+  "bin": "compat/cli.cjs",
+  "type": "module",
+  "exports": "./index.js",
   "scripts": {
-    "test": "standard && depcheck && node cli.js && tape test/*.js",
+    "test": "standard && depcheck --ignores subarg && node cli.js && tape test/*.js",
     "hallmark": "node cli.js --fix",
     "check-licenses": "npm-consider install --test --production"
   },
   "files": [
     "CHANGELOG.md",
     "cli.js",
+    "compat",
     "index.js",
     "lint.js",
     "USAGE"
@@ -56,12 +58,12 @@
     "vfile-reporter-shiny": "^0.1.2"
   },
   "devDependencies": {
-    "depcheck": "^1.2.0",
+    "depcheck": "^1.4.2",
     "git-pull-or-clone": "^2.0.1",
     "npm-consider": "^1.7.0",
     "standard": "^16.0.4",
-    "tape": "^5.0.1",
-    "tempy": "0.2.1"
+    "tape": "github:substack/tape#d487add",
+    "tempy": "^2.0.0"
   },
   "repository": {
     "type": "git",
@@ -84,7 +86,7 @@
     "unified"
   ],
   "engines": {
-    "node": ">=6"
+    "node": ">=14"
   },
   "config": {
     "allowedLicenseTypes": [