diff --git a/lib/shared/mention-utils.test.js b/lib/shared/mention-utils.test.js
new file mode 100644
--- /dev/null
+++ b/lib/shared/mention-utils.test.js
@@ -0,0 +1,62 @@
+// @flow
+
+import {
+  encodeChatMentionText,
+  decodeChatMentionText,
+  getRawChatMention,
+  renderChatMentionsWithAltText,
+} from './mention-utils.js';
+import type { ResolvedThreadInfo } from '../types/thread-types.js';
+
+describe('encodeChatMentionText', () => {
+  it('should encode closing brackets', () => {
+    expect(encodeChatMentionText('[[test]test')).toEqual('[[test\\]test');
+    expect(encodeChatMentionText('test]]test')).toEqual('test\\]\\]test');
+    expect(encodeChatMentionText('test]')).toEqual('test\\]');
+    expect(encodeChatMentionText('test ] ] ]] asd] d]d')).toEqual(
+      'test \\] \\] \\]\\] asd\\] d\\]d',
+    );
+  });
+});
+
+describe('decodeChatMentionText', () => {
+  it('should decode closing brackets', () => {
+    expect(decodeChatMentionText('test\\]')).toEqual('test]');
+    expect(decodeChatMentionText('test\\]\\]')).toEqual('test]]');
+    expect(decodeChatMentionText('test \\] test')).toEqual('test ] test');
+  });
+  it('should not decode already decoded closing brackets', () => {
+    expect(decodeChatMentionText('test]]')).toEqual('test]]');
+    expect(decodeChatMentionText('test]')).toEqual('test]');
+    expect(decodeChatMentionText('test ] test')).toEqual('test ] test');
+  });
+});
+
+describe('getRawChatMention', () => {
+  it('should return raw chat mention', () =>
+    expect(
+      getRawChatMention({
+        ...(({}: any): ResolvedThreadInfo),
+        id: '256|123',
+        uiName: 'thread-name',
+      }),
+    ).toEqual('@[[256|123:thread-name]]'));
+
+  it('should return raw chat mention with encoded text', () =>
+    expect(
+      getRawChatMention({
+        ...(({}: any): ResolvedThreadInfo),
+        id: '256|123',
+        uiName: 'thread-]name]]',
+      }),
+    ).toEqual('@[[256|123:thread-\\]name\\]\\]]]'));
+});
+
+describe('renderChatMentionsWithAltText', () => {
+  it('should render chat mentions with alternative text', () =>
+    expect(
+      renderChatMentionsWithAltText(
+        'This is a test @[[256|123:thread-name]] @[[256|123:thread-\\]name2\\]\\]]]',
+      ),
+    ).toEqual('This is a test @thread-name @thread-]name2]]'));
+});