feat: test telemetry

Cargo.toml

@@ -24,6 +24,7 @@ tracing = { version = "0.1", features = ["log"] }
 tracing-subscriber = { version = "0.3", features = ["registry", "env-filter"] }
 tracing-bunyan-formatter = "0.3"
 tracing-log = "0.1"
+once_cell = "1"
 
 [dev-dependencies]
 reqwest = { version = "0.11", features = ["json"] }

src/main.rs

@@ -9,7 +9,7 @@ async fn main() -> Result<(), std::io::Error> {
     // Logger setup
     LogTracer::init().expect("Failed to set logger");
     // Info or above will be logged if the RUST_LOG environment variable is not set
-    let subscriber = get_subscriber("zero2prod".into(), "info".into());
+    let subscriber = get_subscriber("zero2prod".into(), "info".into(), std::io::stdout);
     set_global_default(subscriber).expect("Failed to set subscriber");
 
     // We want to panic if we cannot read the configuration

src/telemetry.rs

@@ -1,7 +1,7 @@
 use tracing::{subscriber::set_global_default, Subscriber};
 use tracing_bunyan_formatter::{BunyanFormattingLayer, JsonStorageLayer};
 use tracing_log::LogTracer;
-use tracing_subscriber::{layer::SubscriberExt, EnvFilter, Registry};
+use tracing_subscriber::{fmt::MakeWriter, layer::SubscriberExt, EnvFilter, Registry};
 
 /// Compose multiple layers into a `tracing`'s subscriber.
 ///
@@ -13,10 +13,17 @@ use tracing_subscriber::{layer::SubscriberExt, EnvFilter, Registry};
 /// We need to explicitly call out that the returned subscriber is
 /// `Send` and `Sync` to make it possible to pass it to `init_subscriber`
 /// later on.
-pub fn get_subscriber(name: String, env_filter: String) -> impl Subscriber + Send + Sync {
+pub fn get_subscriber<Sink>(
+    name: String,
+    env_filter: String,
+    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.into(), std::io::stdout);
+    let formatting_layer = BunyanFormattingLayer::new(name.into(), sink);
     Registry::default()
         .with(env_filter)
         .with(JsonStorageLayer)

tests/health_check.rs

@@ -1,14 +1,34 @@
+use once_cell::sync::Lazy;
 use sqlx::{Connection, Executor, PgConnection, PgPool};
 use std::net::TcpListener;
 use uuid::Uuid;
-use zero2prod::configurations::get_configuration;
+use zero2prod::{
+    configurations::get_configuration,
+    telemetry::{get_subscriber, inti_subscriber},
+};
 
 pub struct TestApp {
     pub address: String,
     pub db_pool: sqlx::PgPool,
 }
 
+static TRACING: Lazy<()> = Lazy::new(|| {
+    let default_filter_level = "info".into();
+    let subscriber_name = "test".into();
+
+    if std::env::var("TEST_LOG").is_ok() {
+        let subscriber = get_subscriber(subscriber_name, default_filter_level, std::io::stdout);
+        inti_subscriber(subscriber);
+    } else {
+        let subscriber = get_subscriber(subscriber_name, default_filter_level, std::io::sink);
+        inti_subscriber(subscriber);
+    }
+});
+
 async fn spawn_app() -> TestApp {
+    // This is only executed once thanks to `Lazy`
+    Lazy::force(&TRACING);
+
     let listener = TcpListener::bind("127.0.0.1:0").expect("Failed to bind random port");
     let port = listener.local_addr().unwrap().port();
     let address = format!("http://127.0.0.1:{port}");