fix(highlight): Do not let highlight exceed text range

Author: ajwild

src/highlight-support.js

@@ -45,8 +45,9 @@ const highlightSupport = {
       this.win
     )
 
-    const actualStartIndex = startIndex
-    const actualEndIndex = endIndex
+    // Do not let highlight exceed text range
+    const actualStartIndex = Math.min(Math.max(startIndex, 0), blockText.length - 1)
+    const actualEndIndex = Math.min(Math.max(endIndex, 1), blockText.length)
 
     // If text is provided then validate that it matches
     if (text && text !== blockText.slice(actualStartIndex, actualEndIndex)) {