feat(test): spin up new logical database tests

- Tests will use new database every run
- Added chrono and uuid dependencies.
- Updated documentation

Cargo.lock

@@ -611,11 +611,13 @@ name = "email_newsletter_api"
 version = "0.1.0"
 dependencies = [
  "actix-web",
+ "chrono",
  "config",
  "reqwest",
  "serde",
  "sqlx",
  "tokio",
+ "uuid",
 ]
 
 [[package]]
@@ -2609,6 +2611,9 @@ name = "uuid"
 version = "1.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a183cf7feeba97b4dd1c0d46788634f6221d87fa961b305bed08c851829efcc0"
+dependencies = [
+ "getrandom",
+]
 
 [[package]]
 name = "vcpkg"

Cargo.toml

@@ -20,6 +20,8 @@ reqwest = "0.12.2"
 serde = { version = "1.0.197", features = ["derive"] }
 tokio = { version = "1.36.0", features = ["full"] }
 config = "0.13"
+uuid = { version = "1.8.0", features = ["v4"] }
+chrono = { version = "0.4.38", default-features = false, features = ["clock"] }
 
 [dependencies.sqlx]
 version = "0.7"

docs/actix_web.md

@@ -8,3 +8,5 @@ When we set up our web app, we can attach a resource to the app with `app_data`.
 
 In our app, we want to inject a `db_conn` to the route handlers, so that these routes can handle PostgreSQL read/write.
 
+Since the database connection is a TCP connection that is NOT `Clone`-able. We use Rust's `Arc` (Atomic Reference Counter) as a wrapper around this connection. Each instance of our web app, instead of getting a raw TCP connection to the PostgreSQL database, will be given the pointer to the memory region of `db_conn`.
+

src/configuration.rs

@@ -31,4 +31,11 @@ impl DatabaseSettings {
             self.username, self.password, self.host, self.port, self.database_name
         )
     }
+
+    pub fn connection_string_without_db(&self) -> String {
+        format!(
+            "postgres://{}:{}@{}:{}",
+            self.username, self.password, self.host, self.port
+        )
+    }
 }

src/main.rs

@@ -1,11 +1,16 @@
 use std::net::TcpListener;
 
 use email_newsletter_api::{configuration::get_configuration, startup};
+use sqlx::PgPool;
 
 #[tokio::main]
 async fn main() -> Result<(), std::io::Error> {
     let configuration = get_configuration().expect("Failed to read configuration");
 
+    let db_conn = PgPool::connect(&configuration.database.connection_string())
+        .await
+        .expect("Failed to connect to PostgreSQL");
+
     let port_number = configuration.application_port;
 
     let listener = TcpListener::bind(format!("127.0.0.1:{}", port_number))
@@ -13,5 +18,5 @@ async fn main() -> Result<(), std::io::Error> {
 
     // Move the error up the call stack
     // otherwise await for the HttpServer
-    startup::run(listener)?.await
+    startup::run(listener, db_conn)?.await
 }

src/routes/subscriptions.rs

@@ -1,4 +1,7 @@
 use actix_web::{web, HttpResponse};
+use chrono::Utc;
+use sqlx::PgPool;
+use uuid::Uuid;
 
 #[derive(serde::Deserialize)]
 pub struct FormData {
@@ -6,6 +9,27 @@ pub struct FormData {
     name: String,
 }
 
-pub async fn subscribe_route(_form: web::Form<FormData>) -> HttpResponse {
+pub async fn subscribe_route(
-    HttpResponse::Ok().finish()
+    form: web::Form<FormData>,
+    db_conn_pool: web::Data<PgPool>,
+) -> HttpResponse {
+    match sqlx::query!(
+        r#"
+            INSERT INTO subscriptions (id, email, name, subscribed_at)
+            VALUES ($1, $2, $3, $4)
+        "#,
+        Uuid::new_v4(),
+        form.email,
+        form.name,
+        Utc::now()
+    )
+    .execute(db_conn_pool.get_ref())
+    .await
+    {
+        Ok(_) => HttpResponse::Ok().finish(),
+        Err(e) => {
+            println!("Failed to execute query: {}", e);
+            HttpResponse::InternalServerError().finish()
+        }
+    }
 }

src/startup.rs

@@ -1,13 +1,19 @@
 use crate::routes::{healthcheck_route, subscribe_route};
 use actix_web::dev::Server;
 use actix_web::{web, App, HttpServer};
+use sqlx::PgPool;
 use std::net::TcpListener;
 
-pub fn run(listener: TcpListener) -> Result<Server, std::io::Error> {
+pub fn run(listener: TcpListener, db_conn_pool: PgPool) -> Result<Server, std::io::Error> {
-    let server = HttpServer::new(|| {
+    // under the hood, web::Data::new will create an Arc
+    // to make the TCP connection to PostgreSQL clone-able
+    let db_conn_pool = web::Data::new(db_conn_pool);
+
+    let server = HttpServer::new(move || {
         App::new()
             .route("/health_check", web::get().to(healthcheck_route))
             .route("/subscribe", web::post().to(subscribe_route))
+            .app_data(db_conn_pool.clone())
     })
     .listen(listener)?
     .run();

tests/health_check.rs

@@ -4,12 +4,12 @@ use test_utils::spawn_app;
 
 #[tokio::test]
 async fn health_check_works() {
-    let server_address = spawn_app();
+    let test_app = spawn_app().await;
 
     let client = reqwest::Client::new();
 
     let response = client
-        .get(&format!("{}/health_check", &server_address))
+        .get(&format!("{}/health_check", &test_app.address))
         .send()
         .await
         .expect("Failed to execute health_check request.");

tests/subscribe.rs

@@ -1,27 +1,17 @@
 mod test_utils;
 
-use email_newsletter_api::configuration::{self, get_configuration};
-use sqlx::{Connection, PgConnection};
 use test_utils::spawn_app;
 
 #[tokio::test]
 async fn subscribe_returns_a_200_for_valid_form_data() {
-    let server_address = spawn_app();
+    let test_app = spawn_app().await;
-
-    let configuration = get_configuration().expect("Failed to read configuration");
-
-    let postgres_connection_string = configuration.database.connection_string();
-
-    let mut connection = PgConnection::connect(&postgres_connection_string)
-        .await
-        .expect("Failed to connect to Postgres");
 
     let client = reqwest::Client::new();
 
     let body = "name=le%20test&email=le_test%40gmail.com";
 
     let response = client
-        .post(&format!("{}/subscribe", &server_address))
+        .post(&format!("{}/subscribe", &test_app.address))
         .header("Content-Type", "application/x-www-form-urlencoded")
         .body(body)
         .send()
@@ -32,7 +22,7 @@ async fn subscribe_returns_a_200_for_valid_form_data() {
     assert_eq!(Some(0), response.content_length());
 
     let saved = sqlx::query!("SELECT email, name FROM subscriptions")
-        .fetch_one(&mut connection)
+        .fetch_one(&test_app.db_pool)
         .await
         .expect("Failed to fetch saved subscribtions");
 
@@ -42,7 +32,7 @@ async fn subscribe_returns_a_200_for_valid_form_data() {
 
 #[tokio::test]
 async fn subscribe_returns_a_400_when_data_is_missing() {
-    let server_address = spawn_app();
+    let test_app = spawn_app().await;
 
     let client = reqwest::Client::new();
 
@@ -54,7 +44,7 @@ async fn subscribe_returns_a_400_when_data_is_missing() {
 
     for (invalid_body, error_message) in test_cases {
         let response = client
-            .post(&format!("{}/subscribe", &server_address))
+            .post(&format!("{}/subscribe", &test_app.address))
             .header("Content-Type", "application/x-www-form-urlencoded")
             .body(invalid_body)
             .send()

tests/test_utils.rs

@@ -1,17 +1,31 @@
+use email_newsletter_api::configuration::{get_configuration, DatabaseSettings};
+use sqlx::{Connection, Executor, PgConnection, PgPool};
 use std::net::TcpListener;
+use uuid::Uuid;
+
+pub struct TestApp {
+    pub address: String,
+    pub db_pool: PgPool,
+}
 
-#[allow(dead_code)]
 #[allow(clippy::let_underscore_future)]
-pub fn spawn_app() -> String {
+pub async fn spawn_app() -> TestApp {
     /* Spawn a app server with a TcpListener bound to localhost:<random port>
      *
      *  Returns a valid IPv4 string (i.e localhost:8080)
      */
     let listener = TcpListener::bind("127.0.0.1:0").expect("Failed to bind to a random port");
 
+    let mut configuration = get_configuration().expect("Failed to read configuration");
+
+    configuration.database.database_name = Uuid::new_v4().to_string();
+
+    let db_conn_pool = configure_test_database(&configuration.database).await;
+
     let port = listener.local_addr().unwrap().port();
 
-    let server = email_newsletter_api::startup::run(listener).expect("Failed to bind address");
+    let server = email_newsletter_api::startup::run(listener, db_conn_pool.clone())
+        .expect("Failed to bind address");
 
     /* `tokio::spawn(/*async task*/)` will spawn an async task to be run.
     We can continue executing other code concurrently while `task` runs in the background.
@@ -20,5 +34,30 @@ pub fn spawn_app() -> String {
     (which `#[tokio::test]` will take care for us in the mean time).*/
     let _ = tokio::spawn(server);
 
-    format!("http://127.0.0.1:{}", port)
+    TestApp {
+        address: format!("http://127.0.0.1:{}", port),
+        db_pool: db_conn_pool,
+    }
+}
+
+pub async fn configure_test_database(db_config: &DatabaseSettings) -> PgPool {
+    let mut connection = PgConnection::connect(&db_config.connection_string_without_db())
+        .await
+        .expect("Failed to connect to Postgres");
+
+    connection
+        .execute(format!(r#"CREATE DATABASE "{}";"#, db_config.database_name).as_str())
+        .await
+        .expect("Failed to create database");
+
+    let conn_pool = PgPool::connect(&db_config.connection_string())
+        .await
+        .expect("Failed to connect to PostgreSQL pool");
+
+    sqlx::migrate!("./migrations")
+        .run(&conn_pool)
+        .await
+        .expect("Failed to migrate the database");
+
+    conn_pool
 }