Refactor code-style

package.json

@@ -45,7 +45,7 @@
     "unified": "^10.0.0",
     "unist-builder": "^3.0.0",
     "vfile-find-down": "^6.0.0",
-    "xo": "^0.38.0"
+    "xo": "^0.39.0"
   },
   "scripts": {
     "postinstall": "lerna bootstrap --no-ci",
@@ -71,24 +71,7 @@
     "trailingComma": "none"
   },
   "xo": {
-    "prettier": true,
-    "esnext": false,
-    "rules": {
-      "eqeqeq": [
-        2,
-        "allow-null"
-      ],
-      "guard-for-in": "off",
-      "no-eq-null": "off",
-      "unicorn/no-array-callback-reference": "off",
-      "unicorn/no-array-push-push": "off",
-      "unicorn/no-array-for-each": "off",
-      "prefer-exponentiation-operator": "off",
-      "unicorn/explicit-length-check": "off",
-      "unicorn/no-fn-reference-in-iterator": "off",
-      "unicorn/prefer-includes": "off",
-      "unicorn/prefer-optional-catch-binding": "off"
-    }
+    "prettier": true
   },
   "remarkConfig": {
     "plugins": [

packages/hast-util-from-string/index.js

@@ -35,13 +35,13 @@
  */
 
 export function fromString(node, d) {
-  var value = d == null ? '' : String(d)
+  const value = d === undefined || d === null ? '' : String(d)
 
   if ('children' in node) {
     node.children = []
 
     if (value) {
-      node.children.push({type: 'text', value: value})
+      node.children.push({type: 'text', value})
     }
   } else {
     node.value = value

packages/hast-util-from-string/test.js

@@ -2,7 +2,7 @@ import test from 'tape'
 import {u} from 'unist-builder'
 import {fromString} from './index.js'
 
-test('hast-util-from-string', function (t) {
+test('hast-util-from-string', (t) => {
   t.deepEqual(
     fromString(u('text'), 'foo'),
     u('text', 'foo'),

packages/hast-util-is-body-ok-link/index.js

@@ -25,13 +25,9 @@
 import {isElement} from 'hast-util-is-element'
 import {hasProperty} from 'hast-util-has-property'
 
-var list = ['pingback', 'prefetch', 'stylesheet']
+const list = new Set(['pingback', 'prefetch', 'stylesheet'])
 
 export function isBodyOkLink(node) {
-  var length
-  var index
-  var rel
-
   if (!isElement(node, 'link')) {
     return false
   }
@@ -40,16 +36,15 @@ export function isBodyOkLink(node) {
     return true
   }
 
-  rel = (node.properties || {}).rel || []
-  length = rel.length
-  index = -1
+  const rel = (node.properties || {}).rel || []
+  let index = -1
 
   if (rel.length === 0) {
     return false
   }
 
-  while (++index < length) {
-    if (list.indexOf(rel[index]) === -1) {
+  while (++index < rel.length) {
+    if (!list.has(rel[index])) {
       return false
     }
   }

packages/hast-util-is-body-ok-link/test.js

@@ -3,7 +3,7 @@ import {u} from 'unist-builder'
 import {h} from 'hastscript'
 import {isBodyOkLink} from './index.js'
 
-test('isBodyOkLink', function (t) {
+test('isBodyOkLink', (t) => {
   t.equal(
     isBodyOkLink(h('link', {itemProp: 'foo'})),
     true,

packages/hast-util-is-conditional-comment/index.js

@@ -21,7 +21,7 @@
  *   conditional comments.
  */
 
-var re = /^\[if[ \t\f\n\r]+[^\]]+]|<!\[endif]$/
+const re = /^\[if[ \t\f\n\r]+[^\]]+]|<!\[endif]$/
 
 export function isConditionalComment(node) {
   return node && node.type === 'comment' && re.test(node.value)

packages/hast-util-is-conditional-comment/test.js

@@ -3,8 +3,8 @@ import {u} from 'unist-builder'
 import {h} from 'hastscript'
 import {isConditionalComment} from './index.js'
 
-test('hast-util-is-conditional-comment', function (t) {
-  ;[
+test('hast-util-is-conditional-comment', (t) => {
+  const fixtures = [
     '[if IE]>…<![endif]',
     '[if IE 6]>…<![endif]',
     '[if IE 7]>…<![endif]',
@@ -16,13 +16,17 @@ test('hast-util-is-conditional-comment', function (t) {
     '[if gt IE 6]>…<![endif]',
     '[if !IE]>',
     '<![endif]'
-  ].forEach(function (d) {
+  ]
+  let index = -1
+
+  while (++index < fixtures.length) {
+    const d = fixtures[index]
     t.equal(
       isConditionalComment(u('comment', d)),
       true,
       'yes - <!--' + d + '-->'
     )
-  })
+  }
 
   t.equal(
     isConditionalComment(u('comments', 'foo')),

packages/hast-util-is-css-link/index.js

@@ -23,22 +23,18 @@
  */
 
 export function isCssLink(node) {
-  var props
-  var rel
-  var type
-
   if (!node || node.tagName !== 'link') {
     return false
   }
 
-  props = node.properties || {}
-  rel = props.rel
+  const props = node.properties || {}
+  const rel = props.rel
 
-  if (!rel || !rel.indexOf || rel.indexOf('stylesheet') === -1) {
+  if (!rel || !rel.indexOf || !rel.includes('stylesheet')) {
     return false
   }
 
-  type = String(props.type || '')
+  const type = String(props.type || '')
     .trim()
     .toLowerCase()
 

packages/hast-util-is-css-link/test.js

@@ -3,7 +3,7 @@ import {u} from 'unist-builder'
 import {h} from 'hastscript'
 import {isCssLink} from './index.js'
 
-test('hast-util-is-css-link', function (t) {
+test('hast-util-is-css-link', (t) => {
   t.equal(
     isCssLink(h('link', {rel: ['stylesheet']})),
     true,

packages/hast-util-is-css-style/index.js

@@ -22,13 +22,15 @@
  */
 
 export function isCssStyle(node) {
-  var value
-
   if (!node || node.tagName !== 'style') {
     return false
   }
 
-  value = (node.properties || {}).type
+  const value = (node.properties || {}).type
 
-  return value == null || String(value).trim().toLowerCase() === 'text/css'
+  return (
+    value === undefined ||
+    value === null ||
+    String(value).trim().toLowerCase() === 'text/css'
+  )
 }

packages/hast-util-is-css-style/test.js

@@ -3,7 +3,7 @@ import {u} from 'unist-builder'
 import {h} from 'hastscript'
 import {isCssStyle} from './index.js'
 
-test('hast-util-is-css-style', function (t) {
+test('hast-util-is-css-style', (t) => {
   t.equal(isCssStyle(h('style')), true, 'yes - a `style` node')
   t.equal(
     isCssStyle(h('style', {type: null})),

packages/hast-util-is-event-handler/test.js

@@ -1,7 +1,7 @@
 import test from 'tape'
 import {isEventHandler} from './index.js'
 
-test('hast-util-is-event-handler', function (t) {
+test('hast-util-is-event-handler', (t) => {
   t.ok(isEventHandler('oncut'), 'oncut')
   t.ok(isEventHandler('onend'), 'onend')
   t.ok(isEventHandler('onpushsubscriptionchange'), 'pushsubscriptionchange')

packages/hast-util-is-javascript/index.js

@@ -26,7 +26,7 @@
 import {hasProperty} from 'hast-util-has-property'
 import {isElement} from 'hast-util-is-element'
 
-const mime = [
+const mime = new Set([
   'application/ecmascript',
   'application/javascript',
   'application/x-ecmascript',
@@ -43,7 +43,7 @@ const mime = [
   'text/livescript',
   'text/x-ecmascript',
   'text/x-javascript'
-]
+])
 
 // Check node.
 export function isJavaScript(node) {
@@ -62,13 +62,11 @@ export function isJavaScript(node) {
 
 // Check one value.
 function check(d, prefix) {
-  var value
-
   if (typeof d !== 'string') {
     return false
   }
 
-  value = d.split(';', 1)[0].trim().toLowerCase()
+  const value = d.split(';', 1)[0].trim().toLowerCase()
 
-  return value === '' || mime.indexOf((prefix || '') + value) !== -1
+  return value === '' || mime.has((prefix || '') + value)
 }

packages/hast-util-is-javascript/test.js

@@ -3,7 +3,7 @@ import {u} from 'unist-builder'
 import {h} from 'hastscript'
 import {isJavaScript} from './index.js'
 
-test('hast-util-is-javascript', function (t) {
+test('hast-util-is-javascript', (t) => {
   t.ok(isJavaScript(h('script')), 'yes - for `script`')
   t.ok(
     isJavaScript(h('script', {src: 'index.js'})),

packages/hast-util-to-string/index.js

@@ -41,12 +41,11 @@ function one(node) {
 }
 
 function all(node) {
-  var children = node.children
-  var length = children.length
-  var index = -1
-  var result = []
+  const children = node.children
+  let index = -1
+  const result = []
 
-  while (++index < length) {
+  while (++index < children.length) {
     result[index] = one(children[index])
   }
 

packages/hast-util-to-string/test.js

@@ -2,7 +2,7 @@ import test from 'tape'
 import {u} from 'unist-builder'
 import {toString} from './index.js'
 
-test('hast-util-to-string', function (t) {
+test('hast-util-to-string', (t) => {
   t.deepEqual(toString(u('comment', 'foo')), 'foo', 'should stringify comments')
 
   t.deepEqual(toString(u('text', 'foo')), 'foo', 'should stringify texts')

packages/rehype-concat-css-style/index.js

@@ -20,7 +20,7 @@ export default function rehypeConcatCssStyle() {
 }
 
 function transform(tree) {
-  var matches = []
+  const matches = []
 
   visit(tree, 'element', visitor)
 
@@ -35,17 +35,14 @@ function transform(tree) {
   }
 
   function concat() {
-    var length = matches.length
-    var index = -1
-    var contents = []
-    var match
-    var siblings
+    let index = -1
+    const contents = []
 
-    while (++index < length) {
-      match = matches[index]
+    while (++index < matches.length) {
+      const match = matches[index]
 
       if (index) {
-        siblings = match[0].children
+        const siblings = match[0].children
         siblings.splice(siblings.indexOf(match[1]), 1)
       }
 

packages/rehype-concat-css-style/test.js

@@ -4,7 +4,7 @@ import {u} from 'unist-builder'
 import {h} from 'hastscript'
 import min from './index.js'
 
-test('rehype-concat-css-style', function (t) {
+test('rehype-concat-css-style', (t) => {
   t.deepEqual(
     rehype()
       .use(min)

packages/rehype-concat-javascript/index.js

@@ -20,7 +20,7 @@ export default function rehypeConcatJavaScript() {
 }
 
 function transform(tree) {
-  var matches = []
+  const matches = []
 
   visit(tree, 'element', visitor)
 
@@ -35,17 +35,14 @@ function transform(tree) {
   }
 
   function concat() {
-    var length = matches.length
-    var index = -1
-    var contents = []
-    var match
-    var siblings
+    let index = -1
+    const contents = []
 
-    while (++index < length) {
-      match = matches[index]
+    while (++index < matches.length) {
+      const match = matches[index]
 
       if (index) {
-        siblings = match[0].children
+        const siblings = match[0].children
         siblings.splice(siblings.indexOf(match[1]), 1)
       }
 

packages/rehype-concat-javascript/test.js

@@ -4,7 +4,7 @@ import {u} from 'unist-builder'
 import {h} from 'hastscript'
 import min from './index.js'
 
-test('rehype-concat-javascript', function (t) {
+test('rehype-concat-javascript', (t) => {
   t.deepEqual(
     rehype()
       .use(min)