fix: fix emstrong unicode (#3070)

Author: UziTech

src/Tokenizer.ts

@@ -629,7 +629,7 @@ export class _Tokenizer {
       endReg.lastIndex = 0;
 
       // Clip maskedSrc to same section of string as src (move to lexer?)
-      maskedSrc = maskedSrc.slice(-1 * src.length + match[0].length - 1);
+      maskedSrc = maskedSrc.slice(-1 * src.length + lLength);
 
       while ((match = endReg.exec(maskedSrc)) != null) {
         rDelim = match[1] || match[2] || match[3] || match[4] || match[5] || match[6];
@@ -654,8 +654,9 @@ export class _Tokenizer {
 
         // Remove extra characters. *a*** -> *a*
         rLength = Math.min(rLength, rLength + delimTotal + midDelimTotal);
-
-        const raw = [...src].slice(0, lLength + match.index + rLength + 1).join('');
+        // char length can be >1 for unicode characters;
+        const lastCharLength = [...match[0]][0].length;
+        const raw = src.slice(0, lLength + match.index + lastCharLength + rLength);
 
         // Create `em` if smallest delimiter has odd char count. *a***
         if (Math.min(lLength, rLength) % 2) {

test/specs/new/emoji_inline.html

@@ -18,3 +18,5 @@
 <p><strong>⚠️ test</strong></p>
 <p>Here, the emoji rendering works, but the text doesn't get rendered in italic.</p>
 <p><em>💁 test</em></p>
+<p><em>t💁t</em> test</p>
+<p><strong>t💁t</strong> test</p>

test/specs/new/emoji_inline.md

@@ -37,3 +37,7 @@ Situations where it works:
 Here, the emoji rendering works, but the text doesn't get rendered in italic.
 
 *💁 test*
+
+*t💁t* test
+
+**t💁t** test