Fix support for empty attributes

Closes GH-6.

Reviewed-by: Titus Wormer <[email protected]>

Author: tmelliottjr

lib/index.js

@@ -110,7 +110,7 @@ function parseParameters(value) {
 
   return value
     .replace(
-      /\s+([-\w]+)(?:=(?:"((?:\\[\s\S]|[^"])+)"|'((?:\\[\s\S]|[^'])+)'|((?:\\[\s\S]|[^"'\s])+)))?/gi,
+      /\s+([-\w]+)(?:=(?:"((?:\\[\s\S]|[^"])*)"|'((?:\\[\s\S]|[^'])*)'|((?:\\[\s\S]|[^"'\s])+)))?/gi,
       replacer
     )
     .replace(/\s+/g, '')
@@ -128,14 +128,15 @@ function parseParameters(value) {
   // eslint-disable-next-line max-params
   function replacer(_, $1, $2, $3, $4) {
     /** @type {MarkerParameterValue} */
-    let value = $2 || $3 || $4 || ''
+
+    let value = $2 === undefined ? ($3 === undefined ? $4 : $3) : $2;
     const number = Number(value)
 
-    if (value === 'true' || value === '') {
+    if (value === 'true' || value === undefined) {
       value = true
     } else if (value === 'false') {
       value = false
-    } else if (!Number.isNaN(number)) {
+    } else if (value.trim() && !Number.isNaN(number)) {
       value = number
     }
 

test.js

@@ -164,6 +164,32 @@ test('commentMaker', () => {
     null,
     'marker stop for invalid parameters (#3)'
   )
+
+  html = {type: 'html', value: '<!--foo bar="" -->'}
+
+  assert.deepEqual(
+    commentMarker(html),
+    {
+      name: 'foo',
+      attributes: 'bar=""',
+      parameters: {bar: ''},
+      node: html
+    },
+    'marker with empty string attribute'
+  )
+
+  html = {type: 'html', value: '<!--foo bar="  " -->'}
+
+  assert.deepEqual(
+    commentMarker(html),
+    {
+      name: 'foo',
+      attributes: 'bar="  "',
+      parameters: {bar: '  '},
+      node: html
+    },
+    'marker with whitespace attribute'
+  )
 })
 
 test('comment node', () => {