Optimize regexp for edge whitespace matching. Fix #429.

mixmark-io · Mar 22, 2023 · 77078bd · 77078bd
1 parent 6c956bd
commit 77078bd
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diff --git a/src/node.js b/src/node.js
@@ -39,7 +39,7 @@ function flankingWhitespace (node, options) {
 }
 
 function edgeWhitespace (string) {
-  var m = string.match(/^(([ \t\r\n]*)(\s*))[\s\S]*?((\s*?)([ \t\r\n]*))$/)
+  var m = string.match(/^(([ \t\r\n]*)(\s*))(?:(?=\S)[\s\S]*\S)?((\s*?)([ \t\r\n]*))$/)
   return {
     leading: m[1], // whole string for whitespace-only strings
     leadingAscii: m[2],

diff --git a/test/internals-test.js b/test/internals-test.js
@@ -24,8 +24,10 @@ test('edge whitespace detection',function (t) {
     [`${WS}\xa0`, ews(WS, `\xa0`, '', '')],
     [`HELLO WORLD`, ews('', '', '', '')],
     [``, ews('', '', '', '')],
+    [`TEST${Array(32768).join(' ')}END`, ews('', '', '', '')], // performance check
   ]
   t.plan(TEST_CASES.length)
+  t.timeoutAfter(300)
   var edgeWhitespace = turndownModule.__get__('edgeWhitespace')
   TEST_CASES.forEach(function (c) {
     t.deepEqual(edgeWhitespace(c[0]), c[1])