Refactor to improve bundle size

Author: wooorm

lib/contents.js

@@ -4,23 +4,14 @@ var extend = require('extend')
 
 module.exports = contents
 
-var LIST = 'list'
-var LIST_ITEM = 'listItem'
-var PARAGRAPH = 'paragraph'
-var LINK = 'link'
-var LINK_REFERENCE = 'linkReference'
-var FOOTNOTE = 'footnote'
-var FOOTNOTE_REFERENCE = 'footnoteReference'
-
 // Transform a list of heading objects to a markdown list.
 function contents(map, tight, prefix) {
+  var table = {type: 'list', ordered: false, spread: false, children: []}
   var minDepth = Infinity
   var index = -1
-  var length = map.length
-  var table
 
   // Find minimum depth.
-  while (++index < length) {
+  while (++index < map.length) {
     if (map[index].depth < minDepth) {
       minDepth = map[index].depth
     }
@@ -29,17 +20,14 @@ function contents(map, tight, prefix) {
   // Normalize depth.
   index = -1
 
-  while (++index < length) {
+  while (++index < map.length) {
     map[index].depth -= minDepth - 1
   }
 
-  // Construct the main list.
-  table = list()
-
   // Add TOC to list.
   index = -1
 
-  while (++index < length) {
+  while (++index < map.length) {
     insert(map[index], table, tight, prefix)
   }
 
@@ -48,72 +36,67 @@ function contents(map, tight, prefix) {
 
 // Insert an entry into `parent`.
 function insert(entry, parent, tight, prefix) {
-  var children = parent.children
-  var length = children.length
-  var last = children[length - 1]
-  var index
+  var siblings = parent.children
+  var tail = siblings[siblings.length - 1]
+  var index = -1
   var item
 
   if (entry.depth === 1) {
-    item = listItem()
-
-    item.children.push({
-      type: PARAGRAPH,
+    siblings.push({
+      type: 'listItem',
+      spread: false,
       children: [
         {
-          type: LINK,
-          title: null,
-          url: '#' + (prefix || '') + entry.id,
-          children: all(entry.children)
+          type: 'paragraph',
+          children: [
+            {
+              type: 'link',
+              title: null,
+              url: '#' + (prefix || '') + entry.id,
+              children: all(entry.children)
+            }
+          ]
         }
       ]
     })
-
-    children.push(item)
-  } else if (last && last.type === LIST_ITEM) {
-    insert(entry, last, tight, prefix)
-  } else if (last && last.type === LIST) {
+  } else if (tail && tail.type === 'listItem') {
+    insert(entry, siblings[siblings.length - 1], tight, prefix)
+  } else if (tail && tail.type === 'list') {
     entry.depth--
-
-    insert(entry, last, tight, prefix)
-  } else if (parent.type === LIST) {
-    item = listItem()
-
+    insert(entry, tail, tight, prefix)
+  } else if (parent.type === 'list') {
+    item = {type: 'listItem', spread: false, children: []}
+    siblings.push(item)
     insert(entry, item, tight, prefix)
-
-    children.push(item)
   } else {
-    item = list()
+    item = {type: 'list', ordered: false, spread: false, children: []}
+    siblings.push(item)
     entry.depth--
-
     insert(entry, item, tight, prefix)
-
-    children.push(item)
   }
 
-  // Properly style list-items with new lines.
-  parent.spread = !tight
-
-  if (parent.type === LIST && parent.spread) {
+  if (parent.type === 'list' && !tight) {
     parent.spread = false
-    index = -1
 
-    while (++index < length) {
-      if (children[index].children.length > 1) {
+    while (++index < siblings.length) {
+      if (siblings[index].children.length > 1) {
         parent.spread = true
         break
       }
     }
+  } else {
+    parent.spread = !tight
   }
 }
 
 function all(children) {
   var result = []
-  var length = children ? children.length : 0
   var index = -1
 
-  while (++index < length) {
-    result = result.concat(one(children[index]))
+  if (children) {
+    while (++index < children.length) {
+      result = result.concat(one(children[index]))
+    }
   }
 
   return result
@@ -123,10 +106,10 @@ function one(node) {
   var copy
 
   if (
-    node.type === LINK ||
-    node.type === LINK_REFERENCE ||
-    node.type === FOOTNOTE ||
-    node.type === FOOTNOTE_REFERENCE
+    node.type === 'link' ||
+    node.type === 'linkReference' ||
+    node.type === 'footnote' ||
+    node.type === 'footnoteReference'
   ) {
     return all(node.children)
   }
@@ -144,13 +127,3 @@ function one(node) {
 
   return copy
 }
-
-// Create a list.
-function list() {
-  return {type: LIST, ordered: false, spread: false, children: []}
-}
-
-// Create a list item.
-function listItem() {
-  return {type: LIST_ITEM, spread: false, children: []}
-}

lib/index.js

@@ -11,15 +11,14 @@ function toc(node, options) {
   var settings = options || {}
   var heading = settings.heading ? toExpression(settings.heading) : null
   var result = search(node, heading, settings)
-  var map = result.map
 
-  result.map =
-    map.length === 0 ? null : contents(map, settings.tight, settings.prefix)
+  result.map = result.map.length
+    ? contents(result.map, settings.tight, settings.prefix)
+    : null
 
   // No given heading.
   if (!heading) {
-    result.index = null
-    result.endIndex = null
+    result.endIndex = result.index = null
   }
 
   return result

lib/search.js

@@ -8,86 +8,58 @@ var convert = require('unist-util-is/convert')
 var slugs = require('github-slugger')()
 var toExpression = require('./to-expression')
 
-var heading = convert('heading')
-
 // Search a node for a location.
 function search(root, expression, settings) {
-  var length = root.children.length
-  var depth = null
-  var lookingForToc = expression !== null
-  var maxDepth = settings.maxDepth || 6
-  var skip = settings.skip ? toExpression(settings.skip) : null
+  var skip = settings.skip && toExpression(settings.skip)
   var parents = convert(settings.parents || root)
   var map = []
-  var headingIndex
-  var closingIndex
-
-  if (!lookingForToc) {
-    headingIndex = -1
-  }
+  var index
+  var endIndex
+  var opening
 
   slugs.reset()
 
   // Visit all headings in `root`.  We `slug` all headings (to account for
   // duplicates), but only create a TOC from top-level headings.
   visit(root, 'heading', onheading)
 
-  if (headingIndex && !closingIndex) {
-    closingIndex = length + 1
+  return {
+    index: index || -1,
+    endIndex: index ? endIndex || root.children.length : -1,
+    map: map
   }
 
-  if (headingIndex === undefined) {
-    headingIndex = -1
-    closingIndex = -1
-    map = []
-  }
-
-  return {index: headingIndex, endIndex: closingIndex, map: map}
-
-  function onheading(child, index, parent) {
-    var value = toString(child)
+  function onheading(node, position, parent) {
+    var value = toString(node)
     /* istanbul ignore next - to do: remove this when `remark-attr` is up to
      * date w/ micromark. */
-    var id = child.data && child.data.hProperties && child.data.hProperties.id
+    var id = node.data && node.data.hProperties && node.data.hProperties.id
     var slug = slugs.slug(id || value)
 
     if (!parents(parent)) {
       return
     }
 
-    if (lookingForToc) {
-      if (isClosingHeading(child, depth)) {
-        closingIndex = index
-        lookingForToc = false
-      }
+    // Our opening heading.
+    if (expression && !index && expression.test(value)) {
+      index = position + 1
+      opening = node
+      return
+    }
 
-      if (isOpeningHeading(child, depth, expression)) {
-        headingIndex = index + 1
-        depth = child.depth
-      }
+    // Our closing heading.
+    if (opening && !endIndex && node.depth <= opening.depth) {
+      endIndex = position
     }
 
+    // A non-empty heading after the closing (if we were looking for one).
     if (
-      !lookingForToc &&
       value &&
-      child.depth <= maxDepth &&
+      (endIndex || !expression) &&
+      (!settings.maxDepth || node.depth <= settings.maxDepth) &&
       (!skip || !skip.test(value))
     ) {
-      map.push({
-        depth: child.depth,
-        children: child.children,
-        id: slug
-      })
+      map.push({depth: node.depth, children: node.children, id: slug})
     }
   }
 }
-
-// Check if `node` is the main heading.
-function isOpeningHeading(node, depth, expression) {
-  return depth === null && heading(node) && expression.test(toString(node))
-}
-
-// Check if `node` is the next heading.
-function isClosingHeading(node, depth) {
-  return depth && heading(node) && node.depth <= depth
-}

package.json

@@ -88,6 +88,8 @@
     "prettier": true,
     "esnext": false,
     "rules": {
+      "no-multi-assign": "off",
+      "unicorn/explicit-length-check": "off",
       "unicorn/prefer-optional-catch-binding": "off"
     },
     "ignores": [

readme.md

@@ -125,10 +125,11 @@ An object representing the table of contents.
 ###### Properties
 
 *   `index` (`number?`)
-    — [Index][] of the found table of contents [heading][] in `tree`.
+    — [Index][] of the node right after the  table of contents [heading][].
     `-1` if no heading was found, `null` if no `heading` was given
 *   `endIndex` (`number?`)
-    — [Index][] of the last node after `heading` before the TOC starts.
+    — [Index][] of the first node after `heading` that is not part of its
+    section.
     `-1` if no heading was found, `null` if no `heading` was given,
     same as `index` if there are no nodes between `heading` and the
     first heading in the TOC

test/fixtures/heading-no-contents/config.json

@@ -0,0 +1,3 @@
+{
+  "heading": "fo+"
+}

test/fixtures/heading-no-contents/input.md

@@ -0,0 +1,3 @@
+Some content.
+
+# Foo

test/fixtures/heading-no-contents/output.json

@@ -0,0 +1,5 @@
+{
+  "index": 2,
+  "endIndex": 2,
+  "map": null
+}