refactor: use strict equality in RegExp exec checks (#3935)

Author: singhankit001

src/Lexer.ts

@@ -307,7 +307,7 @@ export class _Lexer<ParserOutput = string, RendererOutput = string> {
     if (this.tokens.links) {
       const links = Object.keys(this.tokens.links);
       if (links.length > 0) {
-        while ((match = this.tokenizer.rules.inline.reflinkSearch.exec(maskedSrc)) != null) {
+        while ((match = this.tokenizer.rules.inline.reflinkSearch.exec(maskedSrc)) !== null) {
           if (links.includes(match[0].slice(match[0].lastIndexOf('[') + 1, -1))) {
             maskedSrc = maskedSrc.slice(0, match.index)
               + '[' + 'a'.repeat(match[0].length - 2) + ']'
@@ -318,13 +318,13 @@ export class _Lexer<ParserOutput = string, RendererOutput = string> {
     }
 
     // Mask out escaped characters
-    while ((match = this.tokenizer.rules.inline.anyPunctuation.exec(maskedSrc)) != null) {
+    while ((match = this.tokenizer.rules.inline.anyPunctuation.exec(maskedSrc)) !== null) {
       maskedSrc = maskedSrc.slice(0, match.index) + '++' + maskedSrc.slice(this.tokenizer.rules.inline.anyPunctuation.lastIndex);
     }
 
     // Mask out other blocks
     let offset;
-    while ((match = this.tokenizer.rules.inline.blockSkip.exec(maskedSrc)) != null) {
+    while ((match = this.tokenizer.rules.inline.blockSkip.exec(maskedSrc)) !== null) {
       offset = match[2] ? match[2].length : 0;
       maskedSrc = maskedSrc.slice(0, match.index + offset) + '[' + 'a'.repeat(match[0].length - offset - 2) + ']' + maskedSrc.slice(this.tokenizer.rules.inline.blockSkip.lastIndex);
     }

src/Tokenizer.ts

@@ -748,7 +748,7 @@ export class _Tokenizer<ParserOutput = string, RendererOutput = string> {
       // Clip maskedSrc to same section of string as src (move to lexer?)
       maskedSrc = maskedSrc.slice(-1 * src.length + lLength);
 
-      while ((match = endReg.exec(maskedSrc)) != null) {
+      while ((match = endReg.exec(maskedSrc)) !== null) {
         rDelim = match[1] || match[2] || match[3] || match[4] || match[5] || match[6];
 
         if (!rDelim) continue; // skip single * in __abc*abc__
@@ -842,7 +842,7 @@ export class _Tokenizer<ParserOutput = string, RendererOutput = string> {
       // Clip maskedSrc to same section of string as src
       maskedSrc = maskedSrc.slice(-1 * src.length + lLength);
 
-      while ((match = endReg.exec(maskedSrc)) != null) {
+      while ((match = endReg.exec(maskedSrc)) !== null) {
         rDelim = match[1] || match[2] || match[3] || match[4] || match[5] || match[6];
 
         if (!rDelim) continue;