Move footnotes to remark-footnotes

Footnotes are now available in `remark-footnotes`, where they received
significant improvements to become much better!

Footnotes parsing has been completely rewritten there, so please take note when
upgrading and switching to `remark-footnotes`.

Upgrade remark, remove the `footnotes: true` option, and instead:

```js
  .use(footnotes, {inlineNotes: true})
```

* Inline notes changed from `[^inline note]` (broken) to `^[inline note]` (works)
* Many bug fixes!

Closes GH-483.

Reviewed-by: Christian Murphy <christian.murphy.42@gmail.com>

packages/remark-parse/lib/defaults.js

@@ -4,7 +4,6 @@ module.exports = {
   position: true,
   gfm: true,
   commonmark: false,
-  footnotes: false,
   pedantic: false,
   blocks: require('./block-elements')
 }

packages/remark-parse/lib/parser.js

@@ -55,8 +55,7 @@ proto.interruptParagraph = [
   ['blockquote'],
   ['html'],
   ['setextHeading', {commonmark: false}],
-  ['definition', {commonmark: false}],
-  ['footnote', {commonmark: false}]
+  ['definition', {commonmark: false}]
 ]
 
 // Nodes that can interupt a list:
@@ -71,8 +70,7 @@ proto.interruptList = [
   ['atxHeading', {pedantic: false}],
   ['fencedCode', {pedantic: false}],
   ['thematicBreak', {pedantic: false}],
-  ['definition', {commonmark: false}],
-  ['footnote', {commonmark: false}]
+  ['definition', {commonmark: false}]
 ]
 
 // Nodes that can interupt a blockquote:
@@ -91,8 +89,7 @@ proto.interruptBlockquote = [
   ['thematicBreak', {commonmark: true}],
   ['html', {commonmark: true}],
   ['list', {commonmark: true}],
-  ['definition', {commonmark: false}],
-  ['footnote', {commonmark: false}]
+  ['definition', {commonmark: false}]
 ]
 
 // Handlers.
@@ -106,7 +103,6 @@ proto.blockTokenizers = {
   list: require('./tokenize/list'),
   setextHeading: require('./tokenize/heading-setext'),
   html: require('./tokenize/html-block'),
-  footnote: require('./tokenize/footnote-definition'),
   definition: require('./tokenize/definition'),
   table: require('./tokenize/table'),
   paragraph: require('./tokenize/paragraph')

packages/remark-parse/lib/tokenize/blank-line.js

@@ -1,11 +1,15 @@
 'use strict'
 
-// A line containing no characters, or a line containing only spaces (U+0020) or tabs (U+0009), is called a blank line.
-// See https://spec.commonmark.org/0.29/#blank-line
+// A line containing no characters, or a line containing only spaces (U+0020) or
+// tabs (U+0009), is called a blank line.
+// See <https://spec.commonmark.org/0.29/#blank-line>.
 var reBlankLine = /^[ \t]*(\n|$)/
 
-// NOTE: Though blank lines play a special role in lists to determine whether the list is tight or loose  (https://spec.commonmark.org/0.29/#blank-lines),
-// it's done by the list tokenizer and this blank-line tokenizer does not have to be responsible for that.
+// Note that though blank lines play a special role in lists to determine
+// whether the list is tight or loose
+// (<https://spec.commonmark.org/0.29/#blank-lines>), it’s done by the list
+// tokenizer and this blank line tokenizer does not have to be responsible for
+// that.
 // Therefore, configs such as `blankLine.notInList` do not have to be set here.
 module.exports = blankLine
 
@@ -17,6 +21,7 @@ function blankLine(eat, value, silent) {
 
   while (index < length) {
     match = reBlankLine.exec(value.slice(index))
+
     if (match == null) {
       break
     }

packages/remark-parse/lib/tokenize/reference.js

@@ -9,21 +9,17 @@ reference.locator = locate
 
 var link = 'link'
 var image = 'image'
-var footnote = 'footnote'
 var shortcut = 'shortcut'
 var collapsed = 'collapsed'
 var full = 'full'
-var space = ' '
 var exclamationMark = '!'
 var leftSquareBracket = '['
 var backslash = '\\'
 var rightSquareBracket = ']'
-var caret = '^'
 
 function reference(eat, value, silent) {
   var self = this
   var commonmark = self.options.commonmark
-  var footnotes = self.options.footnotes
   var character = value.charAt(0)
   var index = 0
   var length = value.length
@@ -55,19 +51,6 @@ function reference(eat, value, silent) {
   intro += character
   queue = ''
 
-  // Check whether we’re eating a footnote.
-  if (footnotes && value.charAt(index) === caret) {
-    // Exit if `![^` is found, so the `!` will be seen as text after this,
-    // and we’ll enter this function again when `[^` is found.
-    if (type === image) {
-      return
-    }
-
-    intro += caret
-    index++
-    type = footnote
-  }
-
   // Eat the text.
   depth = 0
 
@@ -124,13 +107,7 @@ function reference(eat, value, silent) {
 
   character = value.charAt(index)
 
-  // Inline footnotes cannot have a label.
-  // If footnotes are enabled, link labels cannot start with a caret.
-  if (
-    type !== footnote &&
-    character === leftSquareBracket &&
-    (!footnotes || value.charAt(index + 1) !== caret)
-  ) {
+  if (character === leftSquareBracket) {
     identifier = ''
     queue += character
     index++
@@ -187,13 +164,6 @@ function reference(eat, value, silent) {
     return true
   }
 
-  if (type === footnote && content.indexOf(space) !== -1) {
-    return eat(subvalue)({
-      type: footnote,
-      children: this.tokenizeInline(content, eat.now())
-    })
-  }
-
   now = eat.now()
   now.column += intro.length
   now.offset += intro.length
@@ -202,18 +172,15 @@ function reference(eat, value, silent) {
   node = {
     type: type + 'Reference',
     identifier: normalize(identifier),
-    label: identifier
-  }
-
-  if (type === link || type === image) {
-    node.referenceType = referenceType
+    label: identifier,
+    referenceType: referenceType
   }
 
   if (type === link) {
     exit = self.enterLink()
     node.children = self.tokenizeInline(content, now)
     exit()
-  } else if (type === image) {
+  } else {
     node.alt = self.decode.raw(self.unescape(content), now) || null
   }
 

packages/remark-parse/lib/tokenizer.js

@@ -46,11 +46,15 @@ function factory(type) {
         name = methods[index]
         method = tokenizers[name]
 
+        // Previously, we had constructs such as footnotes and YAML that used
+        // these properties.
+        // Those are now external (plus there are userland extensions), that may
+        // still use them.
         if (
           method &&
           /* istanbul ignore next */ (!method.onlyAtStart || self.atStart) &&
-          (!method.notInList || !self.inList) &&
-          (!method.notInBlock || !self.inBlock) &&
+          /* istanbul ignore next */ (!method.notInList || !self.inList) &&
+          /* istanbul ignore next */ (!method.notInBlock || !self.inBlock) &&
           (!method.notInLink || !self.inLink)
         ) {
           valueLength = value.length