Email client, application startup logic and tests

tests/api/health_check.rs

@@ -0,0 +1,16 @@
+use crate::helpers::TestApp;
+
+#[tokio::test]
+async fn health_check_works() {
+    let app = TestApp::spawn().await;
+    let client = reqwest::Client::new();
+
+    let response = client
+        .get(format!("http://{}/health_check", app.address))
+        .send()
+        .await
+        .unwrap();
+
+    assert!(response.status().is_success());
+    assert_eq!(Some(0), response.content_length());
+}

tests/api/helpers.rs

@@ -0,0 +1,74 @@
+use once_cell::sync::Lazy;
+use sqlx::{Connection, Executor, PgConnection, PgPool};
+use uuid::Uuid;
+use zero2prod::{
+    configuration::{DatabaseSettings, get_configuration},
+    startup::Application,
+    telemetry::init_subscriber,
+};
+
+static TRACING: Lazy<()> = Lazy::new(|| {
+    if std::env::var("TEST_LOG").is_ok() {
+        init_subscriber(std::io::stdout);
+    } else {
+        init_subscriber(std::io::sink);
+    }
+});
+
+pub struct TestApp {
+    pub address: String,
+    pub connection_pool: PgPool,
+}
+
+impl TestApp {
+    pub async fn spawn() -> Self {
+        Lazy::force(&TRACING);
+
+        let mut configuration = get_configuration().expect("Failed to read configuration");
+        configuration.database.database_name = Uuid::new_v4().to_string();
+        configuration.application.port = 0;
+        let connection_pool = configure_database(&configuration.database).await;
+        let application = Application::build(configuration)
+            .await
+            .expect("Failed to build application");
+        let address = application.address();
+        let app = TestApp {
+            address,
+            connection_pool,
+        };
+
+        tokio::spawn(application.run_until_stopped());
+
+        app
+    }
+
+    pub async fn post_subscriptions(&self, body: String) -> reqwest::Response {
+        reqwest::Client::new()
+            .post(format!("http://{}/subscriptions", self.address))
+            .header("Content-Type", "application/x-www-form-urlencoded")
+            .body(body)
+            .send()
+            .await
+            .expect("Failed to execute request")
+    }
+}
+
+async fn configure_database(config: &DatabaseSettings) -> PgPool {
+    let mut connection = PgConnection::connect_with(&config.without_db())
+        .await
+        .expect("Failed to connect to Postgres");
+    connection
+        .execute(format!(r#"CREATE DATABASE "{}";"#, config.database_name).as_ref())
+        .await
+        .expect("Failed to create the database");
+
+    let connection_pool = PgPool::connect_with(config.with_db())
+        .await
+        .expect("Failed to connect to Postgres");
+    sqlx::migrate!("./migrations")
+        .run(&connection_pool)
+        .await
+        .expect("Failed to migrate the database");
+
+    connection_pool
+}

tests/api/main.rs

@@ -0,0 +1,3 @@
+mod health_check;
+mod helpers;
+mod subscriptions;

tests/api/subscriptions.rs

@@ -0,0 +1,61 @@
+use crate::helpers::TestApp;
+
+#[tokio::test]
+async fn subscribe_returns_a_200_for_valid_form_data() {
+    let app = TestApp::spawn().await;
+
+    let body = "name=alphonse&email=alphonse.paix%40outlook.com";
+    let response = app.post_subscriptions(body.into()).await;
+
+    assert_eq!(200, response.status().as_u16());
+
+    let saved = sqlx::query!("SELECT email, name FROM subscriptions")
+        .fetch_one(&app.connection_pool)
+        .await
+        .expect("Failed to fetch saved subscription");
+
+    assert_eq!(saved.email, "alphonse.paix@outlook.com");
+    assert_eq!(saved.name, "alphonse");
+}
+
+#[tokio::test]
+async fn subscribe_returns_a_422_when_data_is_missing() {
+    let app = TestApp::spawn().await;
+
+    let test_cases = [
+        ("name=Alphonse", "missing the email"),
+        ("email=alphonse.paix%40outlook.com", "missing the name"),
+        ("", "missing both name and email"),
+    ];
+    for (invalid_body, error_message) in test_cases {
+        let response = app.post_subscriptions(invalid_body.into()).await;
+
+        assert_eq!(
+            422,
+            response.status().as_u16(),
+            "the API did not fail with 422 Unprocessable Entity when the payload was {}.",
+            error_message
+        );
+    }
+}
+
+#[tokio::test]
+async fn subscribe_returns_a_400_when_fields_are_present_but_invalid() {
+    let app = TestApp::spawn().await;
+
+    let test_cases = [
+        ("name=&email=alphonse.paix%40outlook.com", "empty name"),
+        ("name=Alphonse&email=", "empty email"),
+        ("name=Alphonse&email=not-an-email", "invalid email"),
+    ];
+    for (body, description) in test_cases {
+        let response = app.post_subscriptions(body.into()).await;
+
+        assert_eq!(
+            400,
+            response.status().as_u16(),
+            "the API did not return a 400 Bad Request when the payload had an {}.",
+            description
+        );
+    }
+}