Allow sequence of 4+ markers in emphases

In old CommonMark spec they were always parsed literally.

lib/rules_inline/emphasis.js

@@ -24,21 +24,16 @@ function scanDelims(state, start) {
   if (pos >= max) { can_open = false; }
   count = pos - start;
 
-  if (count >= 4) {
+  nextChar = pos < max ? state.src.charCodeAt(pos) : -1;
-    // sequence of four or more unescaped markers can't start/end an emphasis
+
-    can_open = can_close = false;
+  // check whitespace conditions
-  } else {
+  if (nextChar === 0x20 || nextChar === 0x0A) { can_open = false; }
-    nextChar = pos < max ? state.src.charCodeAt(pos) : -1;
+  if (lastChar === 0x20 || lastChar === 0x0A) { can_close = false; }
-
+
-    // check whitespace conditions
+  if (marker === 0x5F /* _ */) {
-    if (nextChar === 0x20 || nextChar === 0x0A) { can_open = false; }
+    // check if we aren't inside the word
-    if (lastChar === 0x20 || lastChar === 0x0A) { can_close = false; }
+    if (isAlphaNum(lastChar)) { can_open = false; }
-
+    if (isAlphaNum(nextChar)) { can_close = false; }
-    if (marker === 0x5F /* _ */) {
-      // check if we aren't inside the word
-      if (isAlphaNum(lastChar)) { can_open = false; }
-      if (isAlphaNum(nextChar)) { can_close = false; }
-    }
   }
 
   return {
@@ -126,19 +121,17 @@ module.exports = function emphasis(state, silent) {
   state.pos = start + startCount;
 
   if (!silent) {
-    if (startCount === 2 || startCount === 3) {
+    // we have `startCount` starting and ending markers,
+    // now trying to serialize them into tokens
+    for (count = startCount; count > 1; count -= 2) {
       state.push({ type: 'strong_open', level: state.level++ });
     }
-    if (startCount === 1 || startCount === 3) {
+    if (count % 2) { state.push({ type: 'em_open', level: state.level++ }); }
-      state.push({ type: 'em_open', level: state.level++ });
-    }
 
     state.parser.tokenize(state);
 
-    if (startCount === 1 || startCount === 3) {
+    if (count % 2) { state.push({ type: 'em_close', level: --state.level }); }
-      state.push({ type: 'em_close', level: --state.level });
+    for (count = startCount; count > 1; count -= 2) {
-    }
-    if (startCount === 2 || startCount === 3) {
       state.push({ type: 'strong_close', level: --state.level });
     }
   }

test/fixtures/commonmark/bad.txt

@@ -1224,146 +1224,6 @@ error:
 </ul>
 
 
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-src line: 4844
-
-.
-____foo__ bar__
-.
-<p><strong><strong>foo</strong> bar</strong></p>
-.
-
-error:
-
-<p>____foo__ bar__</p>
-
-
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-src line: 4850
-
-.
-**foo **bar****
-.
-<p><strong>foo <strong>bar</strong></strong></p>
-.
-
-error:
-
-<p>**foo **bar****</p>
-
-
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-src line: 4977
-
-.
-****foo*
-.
-<p>***<em>foo</em></p>
-.
-
-error:
-
-<p>****foo*</p>
-
-
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-src line: 4989
-
-.
-*foo****
-.
-<p><em>foo</em>***</p>
-.
-
-error:
-
-<p>*foo****</p>
-
-
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-src line: 5056
-
-.
-____foo_
-.
-<p>___<em>foo</em></p>
-.
-
-error:
-
-<p>____foo_</p>
-
-
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-src line: 5068
-
-.
-_foo____
-.
-<p><em>foo</em>___</p>
-.
-
-error:
-
-<p>_foo____</p>
-
-
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-src line: 5104
-
-.
-****foo****
-.
-<p><strong><strong>foo</strong></strong></p>
-.
-
-error:
-
-<p>****foo****</p>
-
-
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-src line: 5110
-
-.
-____foo____
-.
-<p><strong><strong>foo</strong></strong></p>
-.
-
-error:
-
-<p>____foo____</p>
-
-
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-src line: 5120
-
-.
-******foo******
-.
-<p><strong><strong><strong>foo</strong></strong></strong></p>
-.
-
-error:
-
-<p>******foo******</p>
-
-
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-src line: 5134
-
-.
-_____foo_____
-.
-<p><strong><strong><em>foo</em></strong></strong></p>
-.
-
-error:
-
-<p>_____foo_____</p>
-
-
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 src line: 5521
 

test/fixtures/commonmark/good.txt

@@ -3290,6 +3290,24 @@ __foo __bar__ baz__
 <p><strong>foo <strong>bar</strong> baz</strong></p>
 .
 
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+src line: 4844
+
+.
+____foo__ bar__
+.
+<p><strong><strong>foo</strong> bar</strong></p>
+.
+
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+src line: 4850
+
+.
+**foo **bar****
+.
+<p><strong>foo <strong>bar</strong></strong></p>
+.
+
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 src line: 4856
 
@@ -3445,6 +3463,15 @@ src line: 4971
 <p>*<strong>foo</strong></p>
 .
 
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+src line: 4977
+
+.
+****foo*
+.
+<p>***<em>foo</em></p>
+.
+
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 src line: 4983
 
@@ -3454,6 +3481,15 @@ src line: 4983
 <p><strong>foo</strong>*</p>
 .
 
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+src line: 4989
+
+.
+*foo****
+.
+<p><em>foo</em>***</p>
+.
+
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 src line: 4998
 
@@ -3535,6 +3571,15 @@ ___foo__
 <p>_<strong>foo</strong></p>
 .
 
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+src line: 5056
+
+.
+____foo_
+.
+<p>___<em>foo</em></p>
+.
+
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 src line: 5062
 
@@ -3544,6 +3589,15 @@ __foo___
 <p><strong>foo</strong>_</p>
 .
 
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+src line: 5068
+
+.
+_foo____
+.
+<p><em>foo</em>___</p>
+.
+
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 src line: 5077
 
@@ -3580,6 +3634,33 @@ _*foo*_
 <p><em><em>foo</em></em></p>
 .
 
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+src line: 5104
+
+.
+****foo****
+.
+<p><strong><strong>foo</strong></strong></p>
+.
+
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+src line: 5110
+
+.
+____foo____
+.
+<p><strong><strong>foo</strong></strong></p>
+.
+
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+src line: 5120
+
+.
+******foo******
+.
+<p><strong><strong><strong>foo</strong></strong></strong></p>
+.
+
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 src line: 5128
 
@@ -3589,6 +3670,15 @@ src line: 5128
 <p><strong><em>foo</em></strong></p>
 .
 
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+src line: 5134
+
+.
+_____foo_____
+.
+<p><strong><strong><em>foo</em></strong></strong></p>
+.
+
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 src line: 5142