Add support for preformatted code, also submitted to lucthev/collapse…

…-whitespace#16.

README.md

@@ -65,6 +65,7 @@ var turndownService = new TurndownService({ option: 'value' })
 | `blankReplacement` | rule replacement function | See **Special Rules** below |
 | `keepReplacement` | rule replacement function | See **Special Rules** below |
 | `defaultReplacement` | rule replacement function | See **Special Rules** below |
+| `preformattedCode` | `false` or [`true`](https:/lucthev/collapse-whitespace/issues/16) | `false` |
 
 ## Methods
 

src/collapse-whitespace.js

@@ -41,7 +41,7 @@ function collapseWhitespace (options) {
  if (!element.firstChild || isPre(element)) return
 
  var prevText = null
- var prevVoid = false
+ var keepLeadingWs = false
 
  var prev = null
  var node = next(prev, element, isPre)
@@ -51,7 +51,7 @@ function collapseWhitespace (options) {
  var text = node.data.replace(/[ \r\n\t]+/g, ' ')
 
  if ((!prevText || / $/.test(prevText.data)) &&
- !prevVoid && text[0] === ' ') {
+ !keepLeadingWs && text[0] === ' ') {
  text = text.substr(1)
  }
 
@@ -71,11 +71,14 @@ function collapseWhitespace (options) {
  }
 
  prevText = null
- prevVoid = false
- } else if (isVoid(node)) {
- // Avoid trimming space around non-block, non-BR void elements.
+ keepLeadingWs = false
+ } else if (isVoid(node) || isPre(node)) {
+ // Avoid trimming space around non-block, non-BR void elements and inline PRE.
  prevText = null
- prevVoid = true
+ keepLeadingWs = true
+ } else if (prevText) {
+ // Drop protection if set previously.
+ keepLeadingWs = false
  }
  } else {
  node = remove(node)

src/node.js

@@ -1,10 +1,10 @@
 import { isBlock, isVoid, hasVoid } from './utilities'
 
-export default function Node (node) {
+export default function Node (node, options) {
  node.isBlock = isBlock(node)
  node.isCode = node.nodeName.toLowerCase() === 'code' || node.parentNode.isCode
  node.isBlank = isBlank(node)
- node.flankingWhitespace = flankingWhitespace(node)
+ node.flankingWhitespace = flankingWhitespace(node, options)
  return node
 }
 
@@ -17,28 +17,28 @@ function isBlank (node) {
  )
 }
 
-function flankingWhitespace (node) {
+function flankingWhitespace (node, options) {
  var leading = ''
  var trailing = ''
 
- if (!node.isBlock) {
+ if (!node.isBlock && !(node.isCode && options.preformattedCode)) {
  var hasLeading = /^\s/.test(node.textContent)
  var hasTrailing = /\s$/.test(node.textContent)
  var blankWithSpaces = node.isBlank && hasLeading && hasTrailing
 
- if (hasLeading && !isFlankedByWhitespace('left', node)) {
+ if (hasLeading && !isFlankedByWhitespace('left', node, options)) {
  leading = ' '
  }
 
- if (!blankWithSpaces && hasTrailing && !isFlankedByWhitespace('right', node)) {
+ if (!blankWithSpaces && hasTrailing && !isFlankedByWhitespace('right', node, options)) {
  trailing = ' '
  }
  }
 
  return { leading: leading, trailing: trailing }
 }
 
-function isFlankedByWhitespace (side, node) {
+function isFlankedByWhitespace (side, node, options) {
  var sibling
  var regExp
  var isFlanked
@@ -54,6 +54,8 @@ function isFlankedByWhitespace (side, node) {
  if (sibling) {
  if (sibling.nodeType === 3) {
  isFlanked = regExp.test(sibling.nodeValue)
+ } else if (sibling.nodeName === 'CODE' && options.preformattedCode) {
+ isFlanked = false
  } else if (sibling.nodeType === 1 && !isBlock(sibling)) {
  isFlanked = regExp.test(sibling.textContent)
  }

src/root-node.js

@@ -2,7 +2,7 @@ import collapseWhitespace from './collapse-whitespace'
 import HTMLParser from './html-parser'
 import { isBlock, isVoid } from './utilities'
 
-export default function RootNode (input) {
+export default function RootNode (input, options) {
  var root
  if (typeof input === 'string') {
  var doc = htmlParser().parseFromString(
@@ -19,7 +19,8 @@ export default function RootNode (input) {
  collapseWhitespace({
  element: root,
  isBlock: isBlock,
- isVoid: isVoid
+ isVoid: isVoid,
+ isPre: options.preformattedCode ? isPreOrCode : null
  })
 
  return root
@@ -30,3 +31,7 @@ function htmlParser () {
  _htmlParser = _htmlParser || new HTMLParser()
  return _htmlParser
 }
+
+function isPreOrCode (node) {
+ return node.nodeName === 'PRE' || node.nodeName === 'CODE'
+}

src/turndown.js

@@ -46,7 +46,8 @@ export default function TurndownService (options) {
  },
  defaultReplacement: function (content, node) {
  return node.isBlock ? '\n\n' + content + '\n\n' : content
- }
+ },
+ preformattedCode: false
  }
  this.options = extend({}, defaults, options)
  this.rules = new Rules(this.options)
@@ -70,7 +71,7 @@ TurndownService.prototype = {
 
  if (input === '') return ''
 
- var output = process.call(this, new RootNode(input))
+ var output = process.call(this, new RootNode(input, this.options))
  return postProcess.call(this, output)
  },
 
@@ -145,7 +146,7 @@ TurndownService.prototype = {
 function process (parentNode) {
  var self = this
  return reduce.call(parentNode.childNodes, function (output, node) {
- node = new Node(node)
+ node = new Node(node, self.options)
  var replacement = replacementForNode.call(self, node)
  return join(output, replacement)
  }, '')

test/turndown-test.js

@@ -168,3 +168,27 @@ test('remove elements are overridden by keep', function (t) {
  'Hello <del>world</del><ins>World</ins>'
  )
 })
+
+test('preformattedCode option prevents whitespace collapsing', function (t) {
+ t.plan(4)
+ // Match behavior of `<code>` with CSS set as `white-space: pre-wrap;`, e.g. in GitLab
+ var turndownService = new TurndownService({
+ preformattedCode: true
+ })
+ t.equal(turndownService.turndown(
+ '<p>Four spaces <code> make an indented code block in Markdown</code></p>'),
+ 'Four spaces ` make an indented code block in Markdown`'
+ )
+ t.equal(turndownService.turndown(
+ '<p><code>A line break </code> <b> note the spaces</b></p>'),
+ '`A line break ` **note the spaces**'
+ )
+ t.equal(turndownService.turndown(
+ '<p><b>tight</b><code>code</code><b>wrap</b></p>'),
+ '**tight**`code`**wrap**'
+ )
+ t.equal(turndownService.turndown(
+ '<p><b>not so tight </b><code>code</code><b> wrap</b></p>'),
+ '**not so tight** `code` **wrap**'
+ )
+})