Add support for MDX comment node

See <https://github.com/mdx-js/mdx/blob/c2a7386/docs/advanced/ast.md#mdxast> Closes GH-3.
syntax-tree · Jan 21, 2019 · 1900f4a · 1900f4a
1 parent f1b1f62
commit 1900f4a
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Showing 3 changed files with 163 additions and 61 deletions.
diff --git a/index.js b/index.js
@@ -4,86 +4,49 @@ module.exports = marker
 
 var whiteSpaceExpression = /\s+/g
 
-// Expression for parsing parameters.
-var parametersExpression = new RegExp(
-  '\\s+' +
-    '(' +
-    '[-a-z0-9_]+' +
-    ')' +
-    '(?:' +
-    '=' +
-    '(?:' +
-    '"' +
-    '(' +
-    '(?:' +
-    '\\\\[\\s\\S]' +
-    '|' +
-    '[^"]' +
-    ')+' +
-    ')' +
-    '"' +
-    '|' +
-    "'" +
-    '(' +
-    '(?:' +
-    '\\\\[\\s\\S]' +
-    '|' +
-    "[^']" +
-    ')+' +
-    ')' +
-    "'" +
-    '|' +
-    '(' +
-    '(?:' +
-    '\\\\[\\s\\S]' +
-    '|' +
-    '[^"\'\\s]' +
-    ')+' +
-    ')' +
-    ')' +
-    ')?',
-  'gi'
-)
+var parametersExpression = /\s+([-a-z0-9_]+)(?:=(?:"((?:\\[\s\S]|[^"])+)"|'((?:\\[\s\S]|[^'])+)'|((?:\\[\s\S]|[^"'\s])+)))?/gi
+
+var commentExpression = /\s*([a-zA-Z0-9-]+)(\s+([\s\S]*))?\s*/
 
 var markerExpression = new RegExp(
-  '(' +
-    '\\s*' +
-    '<!--' +
-    '\\s*' +
-    '([a-zA-Z0-9-]+)' +
-    '(\\s+([\\s\\S]*?))?' +
-    '\\s*' +
-    '-->' +
-    '\\s*' +
-    ')'
+  '(\\s*<!--' + commentExpression.source + '-->\\s*)'
 )
 
 // Parse a comment marker.
 function marker(node) {
+  var type
   var value
   var match
   var params
 
-  if (!node || node.type !== 'html') {
+  if (!node) {
+    return null
+  }
+
+  type = node.type
+
+  if (type !== 'html' && type !== 'comment') {
     return null
   }
 
   value = node.value
-  match = value.match(markerExpression)
+  match = value.match(type === 'comment' ? commentExpression : markerExpression)
 
-  if (!match || match[1].length !== value.length) {
+  if (!match || match[0].length !== value.length) {
     return null
   }
 
-  params = parameters(match[3] || '')
+  match = match.slice(node.type === 'comment' ? 1 : 2)
+
+  params = parameters(match[1] || '')
 
   if (!params) {
     return null
   }
 
   return {
-    name: match[2],
-    attributes: match[4] || '',
+    name: match[0],
+    attributes: match[2] || '',
     parameters: params,
     node: node
   }

diff --git a/readme.md b/readme.md
@@ -29,6 +29,12 @@ console.log(marker({
   type: 'html',
   value: '<!doctype html>'
 }));
+
+// Also supports MDX comment nodes.
+console.log(marker({
+  type: 'comment',
+  value: 'bar'
+}));
 ```
 
 Yields:
@@ -45,6 +51,10 @@ Yields:
    { type: 'html',
      value: '<!--foo bar baz=12.4 qux="test test" quux=\'false\'-->' } }
 null
+{ name: 'bar',
+  attributes: '',
+  parameters: {},
+  node: { type: 'comment', value: 'bar' } }
 ```
 
 ## API

diff --git a/test.js b/test.js
@@ -3,7 +3,7 @@
 var test = require('tape')
 var marker = require('.')
 
-test('normalize(value, allowApostrophes)', function(t) {
+test('commentMaker(node)', function(t) {
   var node
 
   t.equal(marker(), null, 'should work without node')
@@ -82,10 +82,7 @@ test('normalize(value, allowApostrophes)', function(t) {
     'marker with double quoted attributes'
   )
 
-  node = {
-    type: 'html',
-    value: "<!--foo bar='baz qux'-->"
-  }
+  node = {type: 'html', value: "<!--foo bar='baz qux'-->"}
 
   t.deepEqual(
     marker(node),
@@ -157,3 +154,135 @@ test('normalize(value, allowApostrophes)', function(t) {
 
   t.end()
 })
+
+test('comment node', function(t) {
+  var node
+
+  t.equal(
+    marker({type: 'comment', value: ' '}),
+    null,
+    'should work for empty comments'
+  )
+
+  node = {type: 'comment', value: 'foo'}
+
+  t.deepEqual(
+    marker(node),
+    {name: 'foo', attributes: '', parameters: {}, node: node},
+    'comment without attributes'
+  )
+
+  node = {type: 'comment', value: ' foo '}
+
+  t.deepEqual(
+    marker(node),
+    {name: 'foo', attributes: '', parameters: {}, node: node},
+    'comment without attributes ignoring spaces'
+  )
+
+  node = {type: 'comment', value: 'foo bar'}
+
+  t.deepEqual(
+    marker(node),
+    {name: 'foo', attributes: 'bar', parameters: {bar: true}, node: node},
+    'comment with boolean attributes'
+  )
+
+  node = {type: 'comment', value: 'foo bar=baz qux'}
+
+  t.deepEqual(
+    marker(node),
+    {
+      name: 'foo',
+      attributes: 'bar=baz qux',
+      parameters: {bar: 'baz', qux: true},
+      node: node
+    },
+    'comment with unquoted attributes'
+  )
+
+  node = {type: 'comment', value: 'foo bar="baz qux"'}
+
+  t.deepEqual(
+    marker(node),
+    {
+      name: 'foo',
+      attributes: 'bar="baz qux"',
+      parameters: {bar: 'baz qux'},
+      node: node
+    },
+    'comment with double quoted attributes'
+  )
+
+  node = {type: 'comment', value: "foo bar='baz qux'"}
+
+  t.deepEqual(
+    marker(node),
+    {
+      name: 'foo',
+      attributes: "bar='baz qux'",
+      parameters: {bar: 'baz qux'},
+      node: node
+    },
+    'comment with single quoted attributes'
+  )
+
+  node = {type: 'comment', value: 'foo bar=3'}
+
+  t.deepEqual(
+    marker(node),
+    {
+      name: 'foo',
+      attributes: 'bar=3',
+      parameters: {bar: 3},
+      node: node
+    },
+    'comment with numbers'
+  )
+
+  node = {type: 'comment', value: 'foo bar=true'}
+
+  t.deepEqual(
+    marker(node),
+    {
+      name: 'foo',
+      attributes: 'bar=true',
+      parameters: {bar: true},
+      node: node
+    },
+    'comment with boolean true'
+  )
+
+  node = {type: 'comment', value: 'foo bar=false'}
+
+  t.deepEqual(
+    marker(node),
+    {
+      name: 'foo',
+      attributes: 'bar=false',
+      parameters: {bar: false},
+      node: node
+    },
+    'comment with boolean false'
+  )
+
+  t.equal(
+    marker({type: 'comment', value: 'foo bar='}),
+    null,
+    'marker stop for invalid parameters (#1)'
+  )
+
+  t.equal(
+    marker({type: 'comment', value: 'foo bar= qux'}),
+    null,
+    'marker stop for invalid parameters (#2)'
+  )
+
+  t.equal(
+    marker({type: 'comment', value: 'foo |'}),
+    null,
+    'marker stop for invalid parameters (#3)'
+  )
+
+  t.end()
+})