[MM-63597] Fix From: autocompletion (#30673)

e2e-tests/playwright/specs/functional/channels/search/search_box_suggestions.spec.ts

@@ -57,3 +57,33 @@ test('Search box suggestion must be case insensitive', async ({pw}) => {
     // * The search box should contain the selected suggestion
     await expect(channelsPage.globalHeader.searchBox.getByText(searchOutput, {exact: true})).toBeVisible();
 });
+
+test('remove extra whitespace when selecting a user', async ({pw}) => {
+    // # Set up test with two users
+    const {user, adminUser: admin} = await pw.initSetup();
+
+    // # Log in as the test user
+    const {channelsPage} = await pw.testBrowser.login(user);
+
+    // # Visit a default channel page
+    await channelsPage.goto();
+    await channelsPage.toBeVisible();
+
+    // # Open the search UI
+    await channelsPage.globalHeader.openSearch();
+
+    // # Type "from:" followed by multiple spaces
+    const {searchInput} = channelsPage.searchPopover;
+    await searchInput.pressSequentially(`from:    ${admin.username}`);
+
+    // * The suggestion should be visible
+    await expect(channelsPage.searchPopover.selectedSuggestion).toBeVisible();
+    await expect(channelsPage.searchPopover.selectedSuggestion).toHaveText(`@` + admin.username);
+
+    // # Press enter to validate the selection
+    await searchInput.press('Enter');
+
+    // * Verify the search box shows "from:username" without extra spaces
+    const expectedText = `from:${admin.username} `;
+    await expect(searchInput).toHaveValue(expectedText);
+});