Refactor to improve bundle size

Author: wooorm

.babelrc

@@ -4,9 +4,9 @@
       "babel-plugin-inline-constants",
       {
         "modules": [
-          "micromark/lib/character/codes",
-          "micromark/lib/constant/constants",
-          "micromark/lib/constant/types"
+          "micromark/dist/character/codes",
+          "micromark/dist/constant/constants",
+          "micromark/dist/constant/types"
         ]
       }
     ]

lib/index.js

@@ -3,9 +3,9 @@
 module.exports = fromMarkdown
 
 // These three are compiled away in the `dist/`
-var codes = require('micromark/lib/character/codes')
-var constants = require('micromark/lib/constant/constants')
-var types = require('micromark/lib/constant/types')
+var codes = require('micromark/dist/character/codes')
+var constants = require('micromark/dist/constant/constants')
+var types = require('micromark/dist/constant/types')
 
 var toString = require('mdast-util-to-string')
 var assign = require('micromark/dist/constant/assign')
@@ -147,12 +147,10 @@ function compiler(options) {
   function compile(events) {
     var stack = [{type: 'root', children: []}]
     var tokenStack = []
-    var index = -1
     var listStack = []
-    var length
+    var index = -1
     var handler
     var listStart
-    var event
 
     var context = {
       stack: stack,
@@ -167,15 +165,13 @@ function compiler(options) {
     }
 
     while (++index < events.length) {
-      event = events[index]
-
       // We preprocess lists to add `listItem` tokens, and to infer whether
       // items the list itself are spread out.
       if (
-        event[1].type === types.listOrdered ||
-        event[1].type === types.listUnordered
+        events[index][1].type === types.listOrdered ||
+        events[index][1].type === types.listUnordered
       ) {
-        if (event[0] === 'enter') {
+        if (events[index][0] === 'enter') {
           listStack.push(index)
         } else {
           listStart = listStack.pop(index)
@@ -185,9 +181,8 @@ function compiler(options) {
     }
 
     index = -1
-    length = events.length
 
-    while (++index < length) {
+    while (++index < events.length) {
       handler = config[events[index][0]]
 
       if (own.call(handler, events[index][1].type)) {
@@ -198,7 +193,7 @@ function compiler(options) {
       }
     }
 
-    if (tokenStack.length > 0) {
+    if (tokenStack.length) {
       throw new Error(
         'Cannot close document, a token (`' +
           tokenStack[tokenStack.length - 1].type +
@@ -214,10 +209,10 @@ function compiler(options) {
     // Figure out `root` position.
     stack[0].position = {
       start: point(
-        length ? events[0][1].start : {line: 1, column: 1, offset: 0}
+        events.length ? events[0][1].start : {line: 1, column: 1, offset: 0}
       ),
       end: point(
-        length
+        events.length
           ? events[events.length - 2][1].end
           : {line: 1, column: 1, offset: 0}
       )
@@ -430,8 +425,7 @@ function compiler(options) {
   }
 
   function resume() {
-    var value = toString(this.stack.pop())
-    return value
+    return toString(this.stack.pop())
   }
 
   //
@@ -555,11 +549,10 @@ function compiler(options) {
       return
     }
 
-    if (getData('setextHeadingSlurpLineEnding')) {
-      return
-    }
-
-    if (config.canContainEols.indexOf(context.type) !== -1) {
+    if (
+      !getData('setextHeadingSlurpLineEnding') &&
+      config.canContainEols.indexOf(context.type) > -1
+    ) {
       onenterdata.call(this, token)
       onexitdata.call(this, token)
     }
@@ -677,6 +670,7 @@ function compiler(options) {
     var data = this.sliceSerialize(token)
     var type = getData('characterReferenceType')
     var value
+    var tail
 
     if (type) {
       value = safeFromInt(
@@ -690,7 +684,7 @@ function compiler(options) {
       value = decode(data)
     }
 
-    var tail = this.stack.pop()
+    tail = this.stack.pop()
     tail.value += value
     tail.position.end = point(token.end)
   }
@@ -793,10 +787,9 @@ function compiler(options) {
 }
 
 function configure(config, extensions) {
-  var length = extensions.length
   var index = -1
 
-  while (++index < length) {
+  while (++index < extensions.length) {
     extension(config, extensions[index])
   }
 
@@ -806,16 +799,14 @@ function configure(config, extensions) {
 function extension(config, extension) {
   var key
   var left
-  var right
 
   for (key in extension) {
     left = own.call(config, key) ? config[key] : (config[key] = {})
-    right = extension[key]
 
     if (key === 'canContainEols') {
-      config[key] = [].concat(left, right)
+      config[key] = [].concat(left, extension[key])
     } else {
-      Object.assign(left, right)
+      Object.assign(left, extension[key])
     }
   }
 }

package.json

@@ -63,7 +63,7 @@
   "scripts": {
     "format": "remark . -qfo && prettier . -w --loglevel warn && xo --fix",
     "generate-dist": "babel lib/ --out-dir dist/ --quiet --retain-lines; prettier dist/ --loglevel error --write",
-    "generate-size": "browserify . -p tinyify -s mdast-util-from-markdown -o mdast-util-from-markdown.min.js; gzip-size mdast-util-from-markdown.min.js",
+    "generate-size": "browserify . -p tinyify -s mdast-util-from-markdown -o mdast-util-from-markdown.min.js; gzip-size mdast-util-from-markdown.min.js --raw",
     "generate": "npm run generate-dist && npm run generate-size",
     "test-api": "node test",
     "test-coverage": "nyc --reporter lcov tape test/index.js",
@@ -90,6 +90,7 @@
     "rules": {
       "complexity": "off",
       "guard-for-in": "off",
+      "unicorn/explicit-length-check": "off",
       "unicorn/no-fn-reference-in-iterator": "off",
       "unicorn/prefer-includes": "off",
       "unicorn/prefer-number-properties": "off",