Fix empty code input in syntax-highlight

CHANGELOG.md

@@ -2,8 +2,10 @@
 
 # 4.2.2-SNAPSHOT
 * Fixed `AsyncDrawable` display when it has placeholder with empty bounds ([#189])
+* Fixed `syntax-highlight` where code input is empty string ([#192])
 
 [#189]: https://github.com/noties/Markwon/issues/189
+[#192]: https://github.com/noties/Markwon/issues/192
 
 # 4.2.1
 * Fix SpannableBuilder `subSequence` method

markwon-syntax-highlight/src/main/java/io/noties/markwon/syntax/Prism4jSyntaxHighlight.java

@@ -41,6 +41,13 @@ public class Prism4jSyntaxHighlight implements SyntaxHighlight {
     @NonNull
     @Override
     public CharSequence highlight(@Nullable String info, @NonNull String code) {
+
+        // @since 4.2.2-SNAPSHOT
+        // although not null, but still is empty
+        if (code.isEmpty()) {
+            return code;
+        }
+
         // if info is null, do not highlight -> LICENCE footer very commonly wrapped inside code
         // block without syntax name specified (so, do not highlight)
         return info == null