Add links to confirmation email

Cargo.toml

@@ -36,6 +36,7 @@ validator = "0.16.1"
 [dev-dependencies]
 claims = "0.7.1"
 fake = "2.9.2"
+linkify = "0.10.0"
 proptest = "1.4.0"
 serde_json = "1.0.114"
 tokio = { version = "1.36.0", features = ["macros", "rt"] }

src/routes/subscriptions.rs

@@ -1,8 +1,10 @@
 use crate::{
     app_state::AppState,
     domain::{NewSubscriber, SubscriberEmail, SubscriberName},
+    email_client::EmailClient,
 };
 use axum::{extract::State, http::StatusCode, routing::post, Form, Router};
+use reqwest::Error;
 use serde::Deserialize;
 use sqlx::PgPool;
 use time::OffsetDateTime;
@@ -36,14 +38,7 @@ async fn subscribe(State(app_state): State<AppState>, Form(form): Form<FormData>
         return StatusCode::INTERNAL_SERVER_ERROR;
     }
 
-    if app_state
-        .email_client
-        .send_email(
-            new_subscriber.email,
-            "Welcome!",
-            "Welcome to our newsletter!",
-            "Welcome to our newsletter!",
-        )
+    if send_confirmation_email(&app_state.email_client, new_subscriber)
         .await
         .is_err()
     {
@@ -81,6 +76,28 @@ async fn insert_subscriber(
     Ok(())
 }
 
+#[tracing::instrument(
+    name = "Sending confirmation email to a new subscriber",
+    skip(email_client, new_subscriber)
+)]
+async fn send_confirmation_email(
+    email_client: &EmailClient,
+    new_subscriber: NewSubscriber,
+) -> Result<(), Error> {
+    let confirmation_link = "https://there-is-no-such-domain.com/subscriptions/confirm";
+    let html_body = format!(
+        "Welcome to our newsletter!<br/>\
+        Click <a href=\"{confirmation_link}\">here</a> to confirm your subscription."
+    );
+    let plain_body = format!(
+        "Welcome to our newsletter!\nVisit {confirmation_link} to confirm your subscription."
+    );
+
+    email_client
+        .send_email(new_subscriber.email, "Welcome!", &html_body, &plain_body)
+        .await
+}
+
 #[derive(Deserialize)]
 struct FormData {
     name: String,

tests/api/subscriptions.rs

@@ -1,10 +1,11 @@
+use crate::helpers::TestApp;
+use linkify::{LinkFinder, LinkKind};
+use serde_json::Value;
 use wiremock::{
     matchers::{method, path},
     Mock, ResponseTemplate,
 };
 
-use crate::helpers::TestApp;
-
 #[tokio::test]
 async fn subscribe_returns_a_200_for_valid_form_data() {
     // given
@@ -105,3 +106,36 @@ async fn subscribe_sends_a_confirmation_email_for_valid_data() {
 
     // then assert
 }
+
+#[tokio::test]
+async fn subscribe_sends_a_confirmation_email_with_a_link() {
+    // given
+    let app = TestApp::spawn().await;
+    let body = "name=Imi%C4%99%20Nazwisko&email=imie.nazwisko%40example.com";
+
+    Mock::given(path("/email"))
+        .and(method("POST"))
+        .respond_with(ResponseTemplate::new(200))
+        .expect(1)
+        .mount(&app.email_server)
+        .await;
+
+    // when
+    app.post_subscriptions(body.into()).await;
+
+    // then
+    let request = &app.email_server.received_requests().await.unwrap()[0];
+    let body: Value = serde_json::from_slice(&request.body).unwrap();
+    let get_link = |s: &str| {
+        let links: Vec<_> = LinkFinder::new()
+            .links(s)
+            .filter(|l| *l.kind() == LinkKind::Url)
+            .collect();
+        assert_eq!(links.len(), 1);
+        links[0].as_str().to_owned()
+    };
+    let html_link = get_link(&body["HtmlBody"].as_str().unwrap());
+    let text_link = get_link(&body["TextBody"].as_str().unwrap());
+
+    assert_eq!(html_link, text_link);
+}