tests: add test subscribe_sends_a_confirmation_email_with_a_link

Cargo.toml

@@ -54,3 +54,4 @@ quickcheck_macros = "1.0.0"
 rand = "0.8.5"
 wiremock = "0.6.0"
 serde_json = "1.0.115"
+linkify = "0.10.0"

tests/api/helpers.rs

@@ -13,6 +13,12 @@ pub struct TestApp {
     pub email_server: MockServer,
 }
 
+/// Confirmation links embedded in the request to the email API.
+pub struct ConfirmationLinks {
+    pub html: reqwest::Url,
+    pub plain_text: reqwest::Url,
+}
+
 impl TestApp {
     pub async fn post_subscriptions(&self, body: String) -> reqwest::Response {
         reqwest::Client::new()
@@ -23,6 +29,30 @@ impl TestApp {
             .await
             .expect("Failed to execute request.")
     }
+
+    /// Extract the confirmation link embedded in the request to the email API.
+    pub fn get_confirmation_links(&self, email_request: &wiremock::Request) -> ConfirmationLinks {
+        let body: serde_json::Value = serde_json::from_slice(&email_request.body).unwrap();
+
+        // Extract the link from one of the request fields.
+        let get_link = |s: &str| {
+            let links: Vec<_> = linkify::LinkFinder::new()
+                .links(s)
+                .filter(|l| *l.kind() == linkify::LinkKind::Url)
+                .collect();
+            assert_eq!(links.len(), 1);
+            let raw_link = links[0].as_str().to_owned();
+            let mut confirmation_link = reqwest::Url::parse(&raw_link).unwrap();
+            // Let's make sure we don't call random APIs on the web
+            assert_eq!(confirmation_link.host_str().unwrap(), "127.0.0.1");
+            confirmation_link.set_port(Some(8000)).unwrap();
+            confirmation_link
+        };
+
+        let html = get_link(body["HtmlBody"].as_str().unwrap());
+        let plain_text = get_link(body["TextBody"].as_str().unwrap());
+        ConfirmationLinks { html, plain_text }
+    }
 }
 
 static TRACING: Lazy<()> = Lazy::new(|| {

tests/api/subscriptions.rs

@@ -21,6 +21,29 @@ async fn subscribe_returns_a_200_for_valid_form_data() {
     assert_eq!(200, response.status().as_u16());
 }
 
+#[tokio::test]
+async fn subscribe_sends_a_confirmation_email_with_a_link() {
+    // Arrange
+    let app = spawn_app().await;
+    let body = "name=le%20guin&email=ursula_le_guin%40gmail.com";
+
+    Mock::given(path("/email"))
+        .and(method("POST"))
+        .respond_with(ResponseTemplate::new(200))
+        .mount(&app.email_server)
+        .await;
+
+    // Act
+    app.post_subscriptions(body.into()).await;
+
+    // Assert
+    let email_request = &app.email_server.received_requests().await.unwrap()[0];
+    let confirmation_links = app.get_confirmation_links(email_request);
+
+    // The two links should be identical
+    assert_eq!(confirmation_links.html, confirmation_links.plain_text);
+}
+
 #[tokio::test]
 async fn subscribe_persists_the_new_subscriber() {
     // Arrange
@@ -84,7 +107,6 @@ async fn subscribe_returns_a_400_when_data_is_missing() {
     }
 }
 
-
 #[tokio::test]
 async fn subscribe_returns_a_400_when_fields_are_present_but_invalid() {
     // Arrange