Flash messages using axum-messages

tests/api/login.rs

@@ -0,0 +1,22 @@
+use crate::helpers::{TestApp, assert_is_redirect_to};
+
+#[tokio::test]
+async fn an_error_flash_message_is_set_on_failure() {
+    let app = TestApp::spawn().await;
+
+    let login_body = serde_json::json!({
+        "username": "user",
+        "password": "password"
+    });
+
+    let response = app.post_login(&login_body).await;
+
+    assert_eq!(response.status().as_u16(), 303);
+    assert_is_redirect_to(&response, "/login");
+
+    let login_page_html = app.get_login_html().await;
+    assert!(login_page_html.contains("Authentication failed"));
+
+    let login_page_html = app.get_login_html().await;
+    assert!(!login_page_html.contains("Authentication failed"));
+}