MarkdownToolBar: Make bold work with newlines

lib/widgets/markdown_toolbar.dart

@@ -132,14 +132,15 @@ TextEditingValue modifyCurrentWord(
   }
   //print('CursorPos: $cursorPos');
 
-  var wordStartPos = text.lastIndexOf(' ', cursorPos == 0 ? 0 : cursorPos - 1);
+  var wordStartPos =
+      text.lastIndexOf(RegExp('\\s'), cursorPos == 0 ? 0 : cursorPos - 1);
   if (wordStartPos == -1) {
     wordStartPos = 0;
   } else {
     wordStartPos += 1;
   }
 
-  var wordEndPos = text.indexOf(' ', cursorPos);
+  var wordEndPos = text.indexOf(RegExp('\\s'), cursorPos);
   if (wordEndPos == -1) {
     wordEndPos = text.length;
   }

test/markdown_toolbar_test.dart

@@ -167,6 +167,16 @@ void main() {
     );
   });
 
+  test("Surrounds the middle word with a newline", () {
+    _testWord(
+      before: 'Hello\nHydra Person',
+      beforeOffset: 8,
+      after: 'Hello\n**Hydra** Person',
+      afterOffset: 13,
+      char: '**',
+    );
+  });
+
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