ch3: enable DB setup in test/CI

Signed-off-by: Jin Dong <jin.dong@databricks.com>

Cargo.toml

@@ -16,9 +16,11 @@ name = "zero2prod"
 
 [dependencies]
 actix-web = "4.5.1"
+chrono = { version = "0.4.35", default-features = false, features = ["clock"] }
 config = "0.14.0"
 serde = { version = "1.0.197", features = ["derive"] }
 tokio = { version = "1.36.0", features = ["macros", "rt-multi-thread"] }
+uuid = { version = "1.8.0", features = ["v4"] }
 
 [dependencies.sqlx]
 version = "0.7.4"

README.md

@@ -19,4 +19,8 @@ cargo tarpaulin --ignore-tests
 To disable a clippy warning: `#[allow(clippy::lint_name)]`
 
 ## TODOs
-- [ ] placeholder
+
+### Ch3
+
+- [ ] Understand `mod`, `pub use` (e.g., in [mod.rs](./src/routes/mod.rs)).
+- [ ] Understand when to use, e.g. `use crate::routes` vs `use zero2prod::startup::run`.

src/configuration.rs

@@ -20,6 +20,13 @@ impl DatabseSettings {
             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
+        )
+    }
 }
 
 pub fn get_configuration() -> Result<Settings, config::ConfigError> {

src/main.rs

@@ -1,10 +1,16 @@
+use sqlx::PgPool;
+use std::net::TcpListener;
 use zero2prod::configuration::get_configuration;
 use zero2prod::startup::run;
 
 #[tokio::main]
 async fn main() -> Result<(), std::io::Error> {
     let configuration = get_configuration().expect("Failed to read configuration");
     let address = format!("127.0.0.1:{}", configuration.application_port);
-    let listener = std::net::TcpListener::bind(address)?;
-    run(listener)?.await
+    let listener = TcpListener::bind(address)?;
+    let connection_pool = PgPool::connect(&configuration.database.connection_string())
+        .await
+        .expect("Failed to connect to Postgres.");
+
+    run(listener, connection_pool)?.await
 }

src/routes/subscriptions.rs

@@ -1,4 +1,7 @@
 use actix_web::{web, HttpResponse, Responder};
+use chrono::Utc;
+use sqlx::PgPool;
+use uuid::Uuid;
 
 #[derive(serde::Deserialize)]
 pub struct FormData {
@@ -7,7 +10,24 @@ pub struct FormData {
 }
 
 //
-pub async fn subscribe(form: web::Form<FormData>) -> impl Responder {
-    print!("email: {}, name: {}", form.email, form.name);
-    HttpResponse::Ok().finish()
+pub async fn subscribe(form: web::Form<FormData>, db_pool: web::Data<PgPool>) -> impl Responder {
+    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_pool.get_ref())
+    .await
+    {
+        Ok(_) => HttpResponse::Ok().finish(),
+        Err(e) => {
+            println!("Failed to execute query: {}", e);
+            HttpResponse::InternalServerError().finish()
+        }
+    }
 }

src/startup.rs

@@ -1,18 +1,21 @@
 use crate::routes::{health_check, subscribe};
 
-use std::net::TcpListener;
-
 use actix_web::dev::Server;
-
 use actix_web::{web, App, HttpServer};
+use sqlx::PgPool;
+use std::net::TcpListener;
+
 // `async` is no longer needed as we don't have .await calls.
-pub fn run(listener: TcpListener) -> Result<Server, std::io::Error> {
-    let server = HttpServer::new(|| {
+pub fn run(listener: TcpListener, db_pool: PgPool) -> Result<Server, std::io::Error> {
+    // create a ARC pointer to the DB connection
+    let db_pool = web::Data::new(db_pool);
+    let server = HttpServer::new(move || {
         App::new()
             // .route("/", web::get().to(greet))
             // .route("/{name}", web::get().to(greet))
             .route("/health_check", web::get().to(health_check))
             .route("/subscriptions", web::post().to(subscribe))
+            .app_data(db_pool.clone())
     })
     .listen(listener)?
     .run();

tests/health_check.rs

@@ -1,26 +1,65 @@
 use std::net::TcpListener;
 
-use sqlx::{PgConnection, Connection};
-use zero2prod::configuration::get_configuration;
+use sqlx::{Connection, Executor, PgConnection, PgPool};
+use uuid::Uuid;
+use zero2prod::configuration::{get_configuration, DatabseSettings};
+
+pub struct TestApp {
+    pub address: String,
+    pub db_pool: PgPool,
+}
+
+async fn spawn_app() -> TestApp {
+    let mut configuration = get_configuration().expect("Failed to read configuration");
+    // create a new database for each test, by using a random name
+    configuration.database.database_name = Uuid::new_v4().to_string();
+
+    let db_pool = configure_database(&configuration.database).await;
 
-fn spawn_app() -> String {
     let listener = TcpListener::bind("127.0.0.1:0").expect("Failed to bind to random port");
     let port = listener.local_addr().unwrap().port();
-    let server = zero2prod::startup::run(listener).expect("Failed to bind address");
+    let address = format!("http://127.0.0.1:{}", port);
+
+    let server =
+        zero2prod::startup::run(listener, db_pool.clone()).expect("Failed to bind address");
     // Launch the server as a background task
     // tokio::spawn returns a handle to the spawned future,
     // but we have no use for it here, hence the non-binding let
     let _ = tokio::spawn(server);
-    format!("http://127.0.0.1:{}", port)
+    TestApp { address, db_pool }
+}
+
+async fn configure_database(config: &DatabseSettings) -> PgPool {
+    // Create database
+    let mut connection = PgConnection::connect(&config.connection_string_without_db())
+        .await
+        .expect("Failed to connect to Postgres.");
+
+    // Migrate database
+    connection
+        .execute(format!(r#"CREATE DATABASE "{}";"#, config.database_name).as_str())
+        .await
+        .expect("Failed to create database.");
+
+    let connection_pool = PgPool::connect(&config.connection_string())
+        .await
+        .expect("Failed to connect to Postgres.");
+
+    sqlx::migrate!("./migrations")
+        .run(&connection_pool)
+        .await
+        .expect("Failed to migrate the database");
+
+    connection_pool
 }
 
 #[tokio::test]
 async fn health_check_works() {
-    let address = spawn_app();
+    let app = spawn_app().await;
     let client = reqwest::Client::new();
 
     let resp = client
-        .get(&format!("{}/health_check", &address))
+        .get(&format!("{}/health_check", &app.address))
         .send()
         .await
         .expect("Failed to execute request.");
@@ -32,17 +71,12 @@ async fn health_check_works() {
 
 #[tokio::test]
 async fn subscribe_returns_200_for_valid_form_data() {
-    let address = spawn_app();
-    let configuration = get_configuration().expect("Failed to read configuration");
-    let connection_string = configuration.database.connection_string();
-    let mut connection = PgConnection::connect(&connection_string)
-        .await
-        .expect("Failed to connect to Postgres.");
+    let app = spawn_app().await;
     let client = reqwest::Client::new();
 
     let body = "name=le%20guin&email=ursula_le_guin%40gmail.com";
     let resp = client
-        .post(&format!("{}/subscriptions", &address))
+        .post(&format!("{}/subscriptions", &app.address))
         .header("Content-Type", "application/x-www-form-urlencoded")
         .body(body)
         .send()
@@ -52,7 +86,7 @@ async fn subscribe_returns_200_for_valid_form_data() {
     assert_eq!(200, resp.status().as_u16());
 
     let saved = sqlx::query!("SELECT email, name FROM subscriptions",)
-        .fetch_one(&mut connection)
+        .fetch_one(&app.db_pool)
         .await
         .expect("Failed to fetch saved subscription.");
 
@@ -62,7 +96,7 @@ async fn subscribe_returns_200_for_valid_form_data() {
 
 #[tokio::test]
 async fn subscribe_returns_400_for_invalid_form_data() {
-    let address = spawn_app();
+    let app = spawn_app().await;
     let client = reqwest::Client::new();
 
     let test_cases = vec![
@@ -73,7 +107,7 @@ async fn subscribe_returns_400_for_invalid_form_data() {
 
     for (invalid_body, err_msg) in test_cases {
         let resp = client
-            .post(&format!("{}/subscriptions", &address))
+            .post(&format!("{}/subscriptions", &app.address))
             .header("Content-Type", "application/x-www-form-urlencoded")
             .body(invalid_body)
             .send()