diff --git a/frontend/app_flowy/packages/appflowy_editor/test/service/internal_key_event_handlers/markdown_syntax_to_styled_text_test.dart b/frontend/app_flowy/packages/appflowy_editor/test/service/internal_key_event_handlers/markdown_syntax_to_styled_text_test.dart
new file mode 100644
index 0000000000..d11a955643
--- /dev/null
+++ b/frontend/app_flowy/packages/appflowy_editor/test/service/internal_key_event_handlers/markdown_syntax_to_styled_text_test.dart
@@ -0,0 +1,154 @@
+import 'package:appflowy_editor/appflowy_editor.dart';
+import 'package:appflowy_editor/src/extensions/text_node_extensions.dart';
+import 'package:flutter/services.dart';
+import 'package:flutter_test/flutter_test.dart';
+import '../../infra/test_editor.dart';
+
+void main() async {
+  setUpAll(() {
+    TestWidgetsFlutterBinding.ensureInitialized();
+  });
+
+  group('markdown_syntax_to_styled_text.dart', () {
+    group('convert single backquote to code', () {
+      Future<void> insertBackquote(
+        EditorWidgetTester editor, {
+        int repeat = 1,
+      }) async {
+        for (var i = 0; i < repeat; i++) {
+          await editor.pressLogicKey(
+            LogicalKeyboardKey.backquote,
+          );
+        }
+      }
+
+      testWidgets('`AppFlowy` to code AppFlowy', (tester) async {
+        const text = '`AppFlowy';
+        final editor = tester.editor..insertTextNode('');
+        await editor.startTesting();
+        await editor.updateSelection(
+          Selection.single(path: [0], startOffset: 0),
+        );
+        final textNode = editor.nodeAtPath([0]) as TextNode;
+        for (var i = 0; i < text.length; i++) {
+          await editor.insertText(textNode, text[i], i);
+        }
+        await insertBackquote(editor);
+        final allCode = textNode.allSatisfyCodeInSelection(
+          Selection.single(
+            path: [0],
+            startOffset: 0,
+            endOffset: textNode.toRawString().length,
+          ),
+        );
+        expect(allCode, true);
+        expect(textNode.toRawString(), 'AppFlowy');
+      });
+
+      testWidgets('App`Flowy` to code AppFlowy', (tester) async {
+        const text = 'App`Flowy';
+        final editor = tester.editor..insertTextNode('');
+        await editor.startTesting();
+        await editor.updateSelection(
+          Selection.single(path: [0], startOffset: 0),
+        );
+        final textNode = editor.nodeAtPath([0]) as TextNode;
+        for (var i = 0; i < text.length; i++) {
+          await editor.insertText(textNode, text[i], i);
+        }
+        await insertBackquote(editor);
+        final allCode = textNode.allSatisfyCodeInSelection(
+          Selection.single(
+            path: [0],
+            startOffset: 3,
+            endOffset: textNode.toRawString().length,
+          ),
+        );
+        expect(allCode, true);
+        expect(textNode.toRawString(), 'AppFlowy');
+      });
+
+      testWidgets('`` nothing changes', (tester) async {
+        const text = '`';
+        final editor = tester.editor..insertTextNode('');
+        await editor.startTesting();
+        await editor.updateSelection(
+          Selection.single(path: [0], startOffset: 0),
+        );
+        final textNode = editor.nodeAtPath([0]) as TextNode;
+        for (var i = 0; i < text.length; i++) {
+          await editor.insertText(textNode, text[i], i);
+        }
+        await insertBackquote(editor);
+        final allCode = textNode.allSatisfyCodeInSelection(
+          Selection.single(
+            path: [0],
+            startOffset: 0,
+            endOffset: textNode.toRawString().length,
+          ),
+        );
+        expect(allCode, false);
+        expect(textNode.toRawString(), text);
+      });
+    });
+
+    group('convert double backquote to code', () {
+      Future<void> insertBackquote(
+        EditorWidgetTester editor, {
+        int repeat = 1,
+      }) async {
+        for (var i = 0; i < repeat; i++) {
+          await editor.pressLogicKey(
+            LogicalKeyboardKey.backquote,
+          );
+        }
+      }
+
+      testWidgets('```AppFlowy`` to code `AppFlowy', (tester) async {
+        const text = '```AppFlowy`';
+        final editor = tester.editor..insertTextNode('');
+        await editor.startTesting();
+        await editor.updateSelection(
+          Selection.single(path: [0], startOffset: 0),
+        );
+        final textNode = editor.nodeAtPath([0]) as TextNode;
+        for (var i = 0; i < text.length; i++) {
+          await editor.insertText(textNode, text[i], i);
+        }
+        await insertBackquote(editor);
+        final allCode = textNode.allSatisfyCodeInSelection(
+          Selection.single(
+            path: [0],
+            startOffset: 1,
+            endOffset: textNode.toRawString().length,
+          ),
+        );
+        expect(allCode, true);
+        expect(textNode.toRawString(), '`AppFlowy');
+      });
+
+      testWidgets('```` nothing changes', (tester) async {
+        const text = '```';
+        final editor = tester.editor..insertTextNode('');
+        await editor.startTesting();
+        await editor.updateSelection(
+          Selection.single(path: [0], startOffset: 0),
+        );
+        final textNode = editor.nodeAtPath([0]) as TextNode;
+        for (var i = 0; i < text.length; i++) {
+          await editor.insertText(textNode, text[i], i);
+        }
+        await insertBackquote(editor);
+        final allCode = textNode.allSatisfyCodeInSelection(
+          Selection.single(
+            path: [0],
+            startOffset: 0,
+            endOffset: textNode.toRawString().length,
+          ),
+        );
+        expect(allCode, false);
+        expect(textNode.toRawString(), text);
+      });
+    });
+  });
+}