health_check.rs

use std::net::TcpListener;

use once_cell::sync::Lazy;
use sqlx::{Connection, Executor, PgConnection, PgPool};
use uuid::Uuid;
use zero2prod::configuration::{get_configuration, DatabseSettings};
use zero2prod::startup::run;
use zero2prod::telemetry::{get_subscriber, init_subscriber};

pub struct TestApp {
    pub address: String,
    pub db_pool: PgPool,
}

// Ensure that the `tracing` stack is only initialized once using `once_cell`.
static TRACING: Lazy<()> = Lazy::new(|| {
    let default_filter_level = "info".to_string();
    let subscriber_name = "test".to_string();

    if std::env::var("TEST_LOG").is_ok() {
        let subscriber = get_subscriber(subscriber_name, default_filter_level, std::io::stdout);
        init_subscriber(subscriber);
    } else {
        let subscriber = get_subscriber(subscriber_name, default_filter_level, std::io::sink);
        init_subscriber(subscriber);
    }
});

async fn spawn_app() -> TestApp {
    // The first time `initialize` is invoked the code in `TRACING` is executed.
    // All other invocations will instead skip execution.
    Lazy::force(&TRACING);

    let listener = TcpListener::bind("127.0.0.1:0").expect("Failed to bind to random port");
    let port = listener.local_addr().unwrap().port();
    let address = format!("http://127.0.0.1:{}", port);

    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;

    let server = 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);
    TestApp { address, db_pool }
}

async fn configure_database(config: &DatabseSettings) -> PgPool {
    // Create database
    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_str())
        .await
        .expect("Failed to create database.");

    // Migrate 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
}

#[tokio::test]
async fn health_check_works() {
    let app = spawn_app().await;
    let client = reqwest::Client::new();

    let resp = client
        .get(&format!("{}/health_check", &app.address))
        .send()
        .await
        .expect("Failed to execute request.");

    assert!(resp.status().is_success());
    print!("{:?}", resp.content_length());
    assert_eq!(Some(0), resp.content_length());
}

#[tokio::test]
async fn subscribe_returns_200_for_valid_form_data() {
    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", &app.address))
        .header("Content-Type", "application/x-www-form-urlencoded")
        .body(body)
        .send()
        .await
        .expect("Failed to execute request.");

    assert_eq!(200, resp.status().as_u16());

    let saved = sqlx::query!("SELECT email, name FROM subscriptions",)
        .fetch_one(&app.db_pool)
        .await
        .expect("Failed to fetch saved subscription.");

    assert_eq!(saved.email, "ursula_le_guin@gmail.com");
    assert_eq!(saved.name, "le guin");
}

#[tokio::test]
async fn subscribe_returns_400_for_invalid_form_data() {
    let app = spawn_app().await;
    let client = reqwest::Client::new();

    let test_cases = vec![
        ("name=le%20guin", "missing the email"),
        ("email=ursula_le_guin%40gmail.com", "missing the name"),
        ("", "missing both name and email"),
    ];

    for (invalid_body, err_msg) in test_cases {
        let resp = client
            .post(&format!("{}/subscriptions", &app.address))
            .header("Content-Type", "application/x-www-form-urlencoded")
            .body(invalid_body)
            .send()
            .await
            .expect("Failed to execute request.");

        assert_eq!(
            400,
            resp.status().as_u16(),
            "The API did not fail with 400 Bad Request when the payload was {}.",
            err_msg
        );
    }
}