feat: implement pagination for user retrieval and update feed fetching logic

thoughts-backend/tests/api/feed.rs

@@ -1,7 +1,10 @@
+use std::time::Duration;
+
 use super::main::{create_user_with_password, setup};
 use axum::http::StatusCode;
 use http_body_util::BodyExt;
 use serde_json::json;
+use tokio::time::sleep;
 use utils::testing::make_jwt_request;
 
 #[tokio::test]
@@ -84,3 +87,80 @@ async fn test_feed_and_user_thoughts() {
     assert_eq!(v["thoughts"][1]["authorUsername"], "user1");
     assert_eq!(v["thoughts"][1]["content"], "A thought from user1");
 }
+
+#[tokio::test]
+async fn test_feed_strict_chronological_order() {
+    let app = setup().await;
+    create_user_with_password(&app.db, "user1", "password123", "u1@e.com").await;
+    create_user_with_password(&app.db, "user2", "password123", "u2@e.com").await;
+    create_user_with_password(&app.db, "user3", "password123", "u3@e.com").await;
+
+    let token1 = super::main::login_user(app.router.clone(), "user1", "password123").await;
+    let token2 = super::main::login_user(app.router.clone(), "user2", "password123").await;
+    let token3 = super::main::login_user(app.router.clone(), "user3", "password123").await;
+
+    make_jwt_request(
+        app.router.clone(),
+        "/users/user2/follow",
+        "POST",
+        None,
+        &token1,
+    )
+    .await;
+    make_jwt_request(
+        app.router.clone(),
+        "/users/user3/follow",
+        "POST",
+        None,
+        &token1,
+    )
+    .await;
+
+    let body_t1 = json!({ "content": "Thought 1 from user2" }).to_string();
+    make_jwt_request(
+        app.router.clone(),
+        "/thoughts",
+        "POST",
+        Some(body_t1),
+        &token2,
+    )
+    .await;
+    sleep(Duration::from_millis(10)).await;
+
+    let body_t2 = json!({ "content": "Thought 2 from user3" }).to_string();
+    make_jwt_request(
+        app.router.clone(),
+        "/thoughts",
+        "POST",
+        Some(body_t2),
+        &token3,
+    )
+    .await;
+    sleep(Duration::from_millis(10)).await;
+
+    let body_t3 = json!({ "content": "Thought 3 from user2" }).to_string();
+    make_jwt_request(
+        app.router.clone(),
+        "/thoughts",
+        "POST",
+        Some(body_t3),
+        &token2,
+    )
+    .await;
+
+    let response = make_jwt_request(app.router.clone(), "/feed", "GET", None, &token1).await;
+    assert_eq!(response.status(), StatusCode::OK);
+
+    let body = response.into_body().collect().await.unwrap().to_bytes();
+    let v: serde_json::Value = serde_json::from_slice(&body).unwrap();
+    let thoughts = v["thoughts"].as_array().unwrap();
+
+    assert_eq!(
+        thoughts.len(),
+        3,
+        "Feed should contain 3 thoughts from followed users"
+    );
+    assert_eq!(thoughts[0]["content"], "Thought 3 from user2");
+    assert_eq!(thoughts[1]["content"], "Thought 2 from user3");
+    assert_eq!(thoughts[2]["content"], "Thought 1 from user2");
+}