MM-T360 - search hashtags from mentions (#30406)

Co-authored-by: Mattermost Build <build@mattermost.com>

e2e-tests/cypress/tests/integration/channels/messaging/at_mentions_user_spec.js

@@ -36,4 +36,41 @@ describe('Mention self', () => {
             });
         });
     });
+
+    it('should be able to click on tryAI hashtag in a message with self-mention', () => {
+        // Create a message that includes both a self-mention and the #tryAI hashtag
+        const message = `Hey @${testUser.username} check out #tryAI`;
+
+        // Post the message
+        cy.postMessage(message);
+
+        // # Open RHS in recent mentions mode
+        cy.findByRole('button', {name: /Recent mentions/i}).click();
+
+        // # Get last postId
+        cy.getLastPostId().as('lastPostId');
+
+        // * Search result should return the message with the self-mention and the #tryAI hashtag
+        cy.get('@lastPostId').then((postId) => {
+            verifySearchResult(postId, message);
+        });
+
+        // # Verify RHS is open and contains the search results
+        cy.get('.sidebar--right__title').should('contain.text', 'Search Results');
+
+        cy.get('@lastPostId').then((postId) => {
+            verifySearchResult(postId, message);
+        });
+    });
 });
+
+// Helper function to verify search result and click on #tryAI hashtag
+function verifySearchResult(postId, fullMessage) {
+    // Find the specific search item container that contains our post ID
+    cy.get(`[data-testid="search-item-container"] #rhsPostMessageText_${postId}`).closest('[data-testid="search-item-container"]').within(() => {
+        cy.get(`#rhsPostMessageText_${postId}`).should('have.text', `${fullMessage}`);
+
+        // This will find the exact element containing just "#tryAI"
+        cy.contains('a', '#tryAI').click({force: true});
+    });
+}