Update to Rust 2021

Also update dependencies and codebase to reflect 2021 standards and changes (tokio tests, etc)

src/configuration.rs

@@ -2,6 +2,7 @@ use std::convert::{TryFrom, TryInto};
 
 use serde_aux::field_attributes::deserialize_number_from_string;
 use sqlx::postgres::{PgConnectOptions, PgSslMode};
+use sqlx::ConnectOptions;
 
 #[derive(serde::Deserialize)]
 pub struct Settings {
@@ -27,6 +28,28 @@ pub struct DatabaseSettings {
     pub require_ssl: bool,
 }
 
+impl DatabaseSettings {
+    pub fn without_db(&self) -> PgConnectOptions {
+        let ssl_mode = if self.require_ssl {
+            PgSslMode::Require
+        } else {
+            PgSslMode::Prefer
+        };
+        PgConnectOptions::new()
+            .host(&self.host)
+            .username(&self.username)
+            .password(&self.password)
+            .port(self.port)
+            .ssl_mode(ssl_mode)
+    }
+
+    pub fn with_db(&self) -> PgConnectOptions {
+        let mut options = self.without_db().database(&self.database_name);
+        options.log_statements(tracing::log::LevelFilter::Trace);
+        options
+    }
+}
+
 pub fn get_configuration() -> Result<Settings, config::ConfigError> {
     // Initialise configuration reader
     let mut settings = config::Config::default();
@@ -77,24 +100,4 @@ impl TryFrom<String> for Environment {
             )),
         }
     }
-}
-
-impl DatabaseSettings {
-    pub fn without_db(&self) -> PgConnectOptions {
-        let ssl_mode = if self.require_ssl {
-            PgSslMode::Require
-        } else {
-            PgSslMode::Prefer
-        };
-        PgConnectOptions::new()
-            .host(&self.host)
-            .username(&self.username)
-            .password(&self.password)
-            .port(self.port)
-            .ssl_mode(ssl_mode)
-    }
-
-    pub fn with_db(&self) -> PgConnectOptions {
-        self.without_db().database(&self.database_name).log_statements(log::LevelFilter::Trace)
-    }
 }

src/lib.rs

@@ -1,3 +1,4 @@
+#![allow(clippy::toplevel_ref_arg)]
 pub mod configuration;
 pub mod routes;
 pub mod startup;

src/main.rs

@@ -5,7 +5,7 @@ use mail_app::startup::run;
 use mail_app::configuration::get_configuration;
 use mail_app::telemetry::{get_subscriber, init_subscriber};
 
-#[actix_web::main]
+#[tokio::main]
 async fn main() -> std::io::Result<()> {
     let subscriber = get_subscriber("mail_app".into(), "info".into(), std::io::stdout);
     init_subscriber(subscriber);

src/routes/subscriptions.rs

@@ -32,13 +32,11 @@ pub async fn subscribe(form: web::Form<FormData>, pool: web::Data<PgPool>,) -> H
     skip(form, pool)
 )]
 pub async fn insert_subscriber(pool: &PgPool, form: &FormData) -> Result<(), sqlx::Error> {
-    // _connect uses PgPool from the application state as defined in startup.rs
-    // Use a match statement for the query as it only returns two outcomes
     sqlx::query!(
         r#"
-        INSERT INTO subscriptions (id, email, name, subscribed_at)
-        VALUES($1, $2, $3, $4)
-        "#,
+    INSERT INTO subscriptions (id, email, name, subscribed_at)
+    VALUES ($1, $2, $3, $4)
+            "#,
         Uuid::new_v4(),
         form.email,
         form.name,

src/startup.rs

@@ -1,6 +1,6 @@
 use actix_web::{web, App, HttpServer};
 use actix_web::dev::Server;
-// use actix_web::web::Data;
+use actix_web::web::Data;
 use std::net::TcpListener;
 use sqlx::PgPool;
 use tracing_actix_web::TracingLogger;
@@ -8,13 +8,13 @@ use tracing_actix_web::TracingLogger;
 use crate::routes::{health_check, subscribe};
 
 pub fn run(listener: TcpListener, db_pool: PgPool) -> Result<Server, std::io::Error> {
-    let db_pool = web::Data::new(db_pool); // Wrap connection in a smart pointer
+    let db_pool = Data::new(db_pool);
     let server = HttpServer::new(move || {
         App::new()
             .wrap(TracingLogger::default())
             .route("/health_check", web::get().to(health_check))
             .route("/subscriptions", web::post().to(subscribe))
-            .app_data(db_pool.clone()) // Get pointer copy and attach to application state
+            .app_data(db_pool.clone())
     })
     .listen(listener)?
     .run();

src/telemetry.rs

@@ -4,17 +4,16 @@ use tracing_log::LogTracer;
 use tracing_subscriber::{layer::SubscriberExt, EnvFilter, Registry, fmt::MakeWriter};
 
 /// Compose multiple layers into a tracing compatible subscriber
-pub fn get_subscriber(
+pub fn get_subscriber<Sink>(
     name: String,
     env_filter: String,
-    sink: impl MakeWriter + Send + Sync + 'static,
-) -> impl Subscriber + Sync + Send {
-    let env_filter = EnvFilter::try_from_default_env()
-        .unwrap_or_else(|_| EnvFilter::new(env_filter));
-    let formatting_layer = BunyanFormattingLayer::new(
-        name,
-        sink
-    );
+    sink: Sink,
+) -> impl Subscriber + Sync + Send
+where
+    Sink: for<'a> MakeWriter<'a> + Send + Sync + 'static,
+{
+    let env_filter = EnvFilter::try_from_default_env().unwrap_or_else(|_| EnvFilter::new(env_filter));
+    let formatting_layer = BunyanFormattingLayer::new(name, sink);
     Registry::default()
         .with(env_filter)
         .with(JsonStorageLayer)