Adding UI Test for Passwordless Flow [fdl deprecation]

FirebaseAuth/Tests/SampleSwift/AuthenticationExampleUITests/AuthenticationExampleUITests.swift

@@ -226,6 +226,35 @@
     removeUIInterruptionMonitor(interruptionMonitor)
   }
 
+  func testEmailLinkSentSuccessfully() {
+    app.staticTexts["Email Link/Passwordless"].tap()
+
+    let testEmail = "[email protected]"
+    app.textFields["Enter Authentication Email"].tap()
+    app.textFields["Enter Authentication Email"].typeText(testEmail)
+    app.buttons["return"].tap() // Dismiss keyboard
+    app.buttons["Send Sign In Link"].tap()
+
+    // Wait for the error message to appear (if there is an error)
+    let errorAlert = app.alerts.staticTexts["Error"]
+    let errorExists = errorAlert.waitForExistence(timeout: 5.0)
+
+    app.swipeDown(velocity: .fast)
+
+    // Assert that there is no error message (success case)
+    // The email sign in link is sent successfully if no error message appears
+    XCTAssertFalse(errorExists, "Error")
+
+    // Go back and check that there is no user that is signed in
+    app.tabBars.firstMatch.buttons.element(boundBy: 1).tap()
+    wait(forElement: app.navigationBars["User"], timeout: 5.0)
+    XCTAssertEqual(
+      app.cells.count,
+      0,
+      "The user shouldn't be signed in and the user view should have no cells."
+    )
+  }
+
   // MARK: - Private Helpers
 
   private func signOut() {