Fix tests

lib/src/format_markdown.dart

@@ -11,9 +11,6 @@ class FormatMarkdown {
     /// String to convert
     String data,
 
-    /// An alternate data source on which to perform formatting
-    String? alternateData,
-
     /// Start index when converting part of [data]
     int fromIndex,
 
@@ -27,6 +24,9 @@ class FormatMarkdown {
 
     /// The curently selected text
     String selectedText = '',
+
+    /// An alternate data source on which to perform formatting
+    String? alternateData,
   }) {
     late String changedData;
     late int replaceCursorIndex;
@@ -74,7 +74,7 @@ class FormatMarkdown {
         break;
       case MarkdownType.blockquote:
         var index = 0;
-        final splitedData = (alternateData ?? data.substring(fromIndex, toIndex)).split('\n');
+        final splitedData = (data.isEmpty ? (alternateData ?? '') : data.substring(fromIndex, toIndex)).split('\n');
         changedData = splitedData.map((value) {
           index++;
           return index == splitedData.length ? '> $value' : '> $value\n';

lib/src/markdown_toolbar.dart

@@ -227,12 +227,12 @@ class MarkdownToolbar extends StatelessWidget {
     ResultMarkdown result = FormatMarkdown.convertToMarkdown(
       type,
       controller.text,
-      getAlternativeSelection?.call(),
       fromIndex,
       toIndex,
       titleSize: titleSize,
       link: link,
       selectedText: selectedText ?? controller.text.substring(fromIndex, toIndex),
+      alternateData: getAlternativeSelection?.call(),
     );
 
     controller.value = controller.value.copyWith(text: result.data, selection: TextSelection.collapsed(offset: fromIndex + result.cursorIndex));