Use ESM

Author: wooorm

.gitignore

@@ -1,6 +1,5 @@
-.DS_Store
-*.log
-.nyc_output/
 coverage/
 node_modules/
+.DS_Store
+*.log
 yarn.lock

.prettierignore

@@ -1,4 +1,3 @@
 coverage/
 *.html
-*.json
 *.md

from-markdown.js

@@ -1,2 +1,182 @@
-exports.fromMarkdown = require('./from-markdown')
-exports.toMarkdown = require('./to-markdown')
+import {ccount} from 'ccount'
+import {findAndReplace} from 'mdast-util-find-and-replace'
+import unicodePunctuation from 'micromark/dist/character/unicode-punctuation.js'
+import unicodeWhitespace from 'micromark/dist/character/unicode-whitespace.js'
+
+var inConstruct = 'phrasing'
+var notInConstruct = ['autolink', 'link', 'image', 'label']
+
+export const gfmAutolinkLiteralFromMarkdown = {
+  transforms: [transformGfmAutolinkLiterals],
+  enter: {
+    literalAutolink: enterLiteralAutolink,
+    literalAutolinkEmail: enterLiteralAutolinkValue,
+    literalAutolinkHttp: enterLiteralAutolinkValue,
+    literalAutolinkWww: enterLiteralAutolinkValue
+  },
+  exit: {
+    literalAutolink: exitLiteralAutolink,
+    literalAutolinkEmail: exitLiteralAutolinkEmail,
+    literalAutolinkHttp: exitLiteralAutolinkHttp,
+    literalAutolinkWww: exitLiteralAutolinkWww
+  }
+}
+
+export const gfmAutolinkLiteralToMarkdown = {
+  unsafe: [
+    {
+      character: '@',
+      before: '[+\\-.\\w]',
+      after: '[\\-.\\w]',
+      inConstruct,
+      notInConstruct
+    },
+    {
+      character: '.',
+      before: '[Ww]',
+      after: '[\\-.\\w]',
+      inConstruct,
+      notInConstruct
+    },
+    {character: ':', before: '[ps]', after: '\\/', inConstruct, notInConstruct}
+  ]
+}
+
+function enterLiteralAutolink(token) {
+  this.enter({type: 'link', title: null, url: '', children: []}, token)
+}
+
+function enterLiteralAutolinkValue(token) {
+  this.config.enter.autolinkProtocol.call(this, token)
+}
+
+function exitLiteralAutolinkHttp(token) {
+  this.config.exit.autolinkProtocol.call(this, token)
+}
+
+function exitLiteralAutolinkWww(token) {
+  this.config.exit.data.call(this, token)
+  this.stack[this.stack.length - 1].url = 'http://' + this.sliceSerialize(token)
+}
+
+function exitLiteralAutolinkEmail(token) {
+  this.config.exit.autolinkEmail.call(this, token)
+}
+
+function exitLiteralAutolink(token) {
+  this.exit(token)
+}
+
+function transformGfmAutolinkLiterals(tree) {
+  findAndReplace(
+    tree,
+    [
+      [/(https?:\/\/|www(?=\.))([-.\w]+)([^ \t\r\n]*)/i, findUrl],
+      [/([-.\w+]+)@([-\w]+(?:\.[-\w]+)+)/, findEmail]
+    ],
+    {ignore: ['link', 'linkReference']}
+  )
+}
+
+function findUrl($0, protocol, domain, path, match) {
+  var prefix = ''
+  var parts
+  var result
+
+  // Not an expected previous character.
+  if (!previous(match)) {
+    return false
+  }
+
+  // Treat `www` as part of the domain.
+  if (/^w/i.test(protocol)) {
+    domain = protocol + domain
+    protocol = ''
+    prefix = 'http://'
+  }
+
+  if (!isCorrectDomain(domain)) {
+    return false
+  }
+
+  parts = splitUrl(domain + path)
+
+  if (!parts[0]) return false
+
+  result = {
+    type: 'link',
+    title: null,
+    url: prefix + protocol + parts[0],
+    children: [{type: 'text', value: protocol + parts[0]}]
+  }
+
+  if (parts[1]) {
+    result = [result, {type: 'text', value: parts[1]}]
+  }
+
+  return result
+}
+
+function findEmail($0, atext, label, match) {
+  // Not an expected previous character.
+  if (!previous(match, true) || /[_-]$/.test(label)) {
+    return false
+  }
+
+  return {
+    type: 'link',
+    title: null,
+    url: 'mailto:' + atext + '@' + label,
+    children: [{type: 'text', value: atext + '@' + label}]
+  }
+}
+
+function isCorrectDomain(domain) {
+  var parts = domain.split('.')
+
+  if (
+    parts.length < 2 ||
+    (parts[parts.length - 1] &&
+      (/_/.test(parts[parts.length - 1]) ||
+        !/[a-zA-Z\d]/.test(parts[parts.length - 1]))) ||
+    (parts[parts.length - 2] &&
+      (/_/.test(parts[parts.length - 2]) ||
+        !/[a-zA-Z\d]/.test(parts[parts.length - 2])))
+  ) {
+    return false
+  }
+
+  return true
+}
+
+function splitUrl(url) {
+  var trail = /[!"&'),.:;<>?\]}]+$/.exec(url)
+  var closingParenIndex
+  var openingParens
+  var closingParens
+
+  if (trail) {
+    url = url.slice(0, trail.index)
+    trail = trail[0]
+    closingParenIndex = trail.indexOf(')')
+    openingParens = ccount(url, '(')
+    closingParens = ccount(url, ')')
+
+    while (closingParenIndex !== -1 && openingParens > closingParens) {
+      url += trail.slice(0, closingParenIndex + 1)
+      trail = trail.slice(closingParenIndex + 1)
+      closingParenIndex = trail.indexOf(')')
+      closingParens++
+    }
+  }
+
+  return [url, trail]
+}
+
+function previous(match, email) {
+  var code = match.input.charCodeAt(match.index - 1)
+  return (
+    (code !== code || unicodeWhitespace(code) || unicodePunctuation(code)) &&
+    (!email || code !== 47)
+  )
+}