Unsubscribe link in emails sent

.sqlx/query-0f552668ea90475e1877425d51727cfe38a9d93571283aa33e8267b42e117e6e.json

@@ -0,0 +1,15 @@
+{
+  "db_name": "PostgreSQL",
+  "query": "UPDATE subscriptions SET status = 'confirmed', unsubscribe_token = $1 WHERE id = $2",
+  "describe": {
+    "columns": [],
+    "parameters": {
+      "Left": [
+        "Text",
+        "Uuid"
+      ]
+    },
+    "nullable": []
+  },
+  "hash": "0f552668ea90475e1877425d51727cfe38a9d93571283aa33e8267b42e117e6e"
+}

.sqlx/query-9ba5df2593c5dc21de727c16f03a76e4922b940c0877132cd5f622c725b9b123.json

@@ -0,0 +1,46 @@
+{
+  "db_name": "PostgreSQL",
+  "query": "\n        SELECT p.post_id, u.username AS author, p.title, p.content, p.published_at\n        FROM posts p\n        LEFT JOIN users u ON p.author_id = u.user_id\n        ORDER BY p.published_at DESC\n        LIMIT $1\n        ",
+  "describe": {
+    "columns": [
+      {
+        "ordinal": 0,
+        "name": "post_id",
+        "type_info": "Uuid"
+      },
+      {
+        "ordinal": 1,
+        "name": "author",
+        "type_info": "Text"
+      },
+      {
+        "ordinal": 2,
+        "name": "title",
+        "type_info": "Text"
+      },
+      {
+        "ordinal": 3,
+        "name": "content",
+        "type_info": "Text"
+      },
+      {
+        "ordinal": 4,
+        "name": "published_at",
+        "type_info": "Timestamptz"
+      }
+    ],
+    "parameters": {
+      "Left": [
+        "Int8"
+      ]
+    },
+    "nullable": [
+      false,
+      false,
+      false,
+      false,
+      false
+    ]
+  },
+  "hash": "9ba5df2593c5dc21de727c16f03a76e4922b940c0877132cd5f622c725b9b123"
+}

.sqlx/query-9bfa261067713ca31b191c9f9bcf19ae0dd2d12a570ce06e8e2abd72c5d7b42d.json

@@ -1,14 +0,0 @@
-{
-  "db_name": "PostgreSQL",
-  "query": "\n        INSERT INTO issue_delivery_queue (\n            newsletter_issue_id,\n            subscriber_email\n        )\n        SELECT $1, email\n        FROM subscriptions\n        WHERE status = 'confirmed'\n        ",
-  "describe": {
-    "columns": [],
-    "parameters": {
-      "Left": [
-        "Uuid"
-      ]
-    },
-    "nullable": []
-  },
-  "hash": "9bfa261067713ca31b191c9f9bcf19ae0dd2d12a570ce06e8e2abd72c5d7b42d"
-}

.sqlx/query-a71a1932b894572106460ca2e34a63dc0cb8c1ba7a70547add1cddbb68133c2b.json

@@ -1,14 +0,0 @@
-{
-  "db_name": "PostgreSQL",
-  "query": "UPDATE subscriptions SET status = 'confirmed' WHERE id = $1",
-  "describe": {
-    "columns": [],
-    "parameters": {
-      "Left": [
-        "Uuid"
-      ]
-    },
-    "nullable": []
-  },
-  "hash": "a71a1932b894572106460ca2e34a63dc0cb8c1ba7a70547add1cddbb68133c2b"
-}

.sqlx/query-ba8d4af43c5654ecce5e396a05681249a28bdcff206d4972f53c8cbd837f8acf.json

@@ -0,0 +1,14 @@
+{
+  "db_name": "PostgreSQL",
+  "query": "DELETE FROM subscriptions WHERE unsubscribe_token = $1",
+  "describe": {
+    "columns": [],
+    "parameters": {
+      "Left": [
+        "Text"
+      ]
+    },
+    "nullable": []
+  },
+  "hash": "ba8d4af43c5654ecce5e396a05681249a28bdcff206d4972f53c8cbd837f8acf"
+}

.sqlx/query-bccf441e3c1c29ddf6f7f13f7a333adf733abc527da03b12c91422b9b20f3a6f.json

@@ -0,0 +1,46 @@
+{
+  "db_name": "PostgreSQL",
+  "query": "\n        SELECT p.post_id, u.username AS author, p.title, p.content, p.published_at\n        FROM posts p\n        LEFT JOIN users u ON p.author_id = u.user_id\n        WHERE p.post_id = $1\n        ",
+  "describe": {
+    "columns": [
+      {
+        "ordinal": 0,
+        "name": "post_id",
+        "type_info": "Uuid"
+      },
+      {
+        "ordinal": 1,
+        "name": "author",
+        "type_info": "Text"
+      },
+      {
+        "ordinal": 2,
+        "name": "title",
+        "type_info": "Text"
+      },
+      {
+        "ordinal": 3,
+        "name": "content",
+        "type_info": "Text"
+      },
+      {
+        "ordinal": 4,
+        "name": "published_at",
+        "type_info": "Timestamptz"
+      }
+    ],
+    "parameters": {
+      "Left": [
+        "Uuid"
+      ]
+    },
+    "nullable": [
+      false,
+      false,
+      false,
+      false,
+      false
+    ]
+  },
+  "hash": "bccf441e3c1c29ddf6f7f13f7a333adf733abc527da03b12c91422b9b20f3a6f"
+}

.sqlx/query-ca8fe28bbf395e1c62a495f7299d404043b35f44f639b0edde61ed9e1a7f2944.json

@@ -0,0 +1,14 @@
+{
+  "db_name": "PostgreSQL",
+  "query": "\n        INSERT INTO issue_delivery_queue (\n            newsletter_issue_id,\n            subscriber_email,\n            unsubscribe_token\n        )\n        SELECT $1, email, unsubscribe_token\n        FROM subscriptions\n        WHERE status = 'confirmed'\n        ",
+  "describe": {
+    "columns": [],
+    "parameters": {
+      "Left": [
+        "Uuid"
+      ]
+    },
+    "nullable": []
+  },
+  "hash": "ca8fe28bbf395e1c62a495f7299d404043b35f44f639b0edde61ed9e1a7f2944"
+}

migrations/20250921113345_add_unsubscribe_token_to_subscriptions.sql

@@ -0,0 +1,5 @@
+ALTER TABLE subscriptions ADD COLUMN unsubscribe_token TEXT UNIQUE;
+
+UPDATE subscriptions
+SET unsubscribe_token = left(md5(random()::text), 25) 
+WHERE status = 'confirmed' AND unsubscribe_token IS NULL;

migrations/20250921152839_add_constraint_to_subscription_tokens_subscriber_id_fkey.sql

@@ -0,0 +1,8 @@
+ALTER TABLE subscription_tokens
+DROP CONSTRAINT subscription_tokens_subscriber_id_fkey;
+
+ALTER TABLE subscription_tokens
+ADD CONSTRAINT subscription_tokens_subscriber_id_fkey
+    FOREIGN KEY (subscriber_id)
+    REFERENCES subscriptions (id)
+    ON DELETE CASCADE;

migrations/20250921230225_add_unsubscribe_token_to_issue_delivery_queue.sql

@@ -0,0 +1 @@
+ALTER TABLE issue_delivery_queue ADD COLUMN unsubscribe_token TEXT NOT NULL;

src/issue_delivery_worker.rs

@@ -44,13 +44,14 @@ pub async fn try_execute_task(
     if task.is_none() {
         return Ok(ExecutionOutcome::EmptyQueue);
     }
-    let (transaction, issue_id, email) = task.unwrap();
+    let (transaction, task) = task.unwrap();
     Span::current()
-        .record("newsletter_issue_id", display(issue_id))
-        .record("subscriber_email", display(&email));
-    match SubscriberEmail::parse(email.clone()) {
+        .record("newsletter_issue_id", display(task.newsletter_issue_id))
+        .record("subscriber_email", display(&task.subscriber_email));
+    match SubscriberEmail::parse(task.subscriber_email.clone()) {
         Ok(email) => {
-            let issue = get_issue(connection_pool, issue_id).await?;
+            let mut issue = get_issue(connection_pool, task.newsletter_issue_id).await?;
+            issue.inject_unsubscribe_token(&task.unsubscribe_token);
             if let Err(e) = email_client
                 .send_email(
                     &email,
@@ -73,7 +74,12 @@ pub async fn try_execute_task(
             );
         }
     }
-    delete_task(transaction, issue_id, &email).await?;
+    delete_task(
+        transaction,
+        task.newsletter_issue_id,
+        &task.subscriber_email,
+    )
+    .await?;
 
     Ok(ExecutionOutcome::TaskCompleted)
 }
@@ -84,6 +90,13 @@ struct NewsletterIssue {
     html_content: String,
 }
 
+impl NewsletterIssue {
+    fn inject_unsubscribe_token(&mut self, token: &str) {
+        self.text_content = self.text_content.replace("UNSUBSCRIBE_TOKEN", token);
+        self.html_content = self.html_content.replace("UNSUBSCRIBE_TOKEN", token);
+    }
+}
+
 #[tracing::instrument(skip_all)]
 async fn get_issue(
     connection_pool: &PgPool,
@@ -103,14 +116,20 @@ async fn get_issue(
     Ok(issue)
 }
 
+pub struct Task {
+    pub newsletter_issue_id: Uuid,
+    pub subscriber_email: String,
+    pub unsubscribe_token: String,
+}
+
 #[tracing::instrument(skip_all)]
 async fn dequeue_task(
     connection_pool: &PgPool,
-) -> Result<Option<(Transaction<'static, Postgres>, Uuid, String)>, anyhow::Error> {
+) -> Result<Option<(Transaction<'static, Postgres>, Task)>, anyhow::Error> {
     let mut transaction = connection_pool.begin().await?;
     let query = sqlx::query!(
         r#"
-        SELECT newsletter_issue_id, subscriber_email
+        SELECT newsletter_issue_id, subscriber_email, unsubscribe_token
         FROM issue_delivery_queue
         FOR UPDATE
         SKIP LOCKED
@@ -119,11 +138,12 @@ async fn dequeue_task(
     );
     let r = transaction.fetch_optional(query).await?;
     if let Some(row) = r {
-        Ok(Some((
-            transaction,
-            row.get("newsletter_issue_id"),
-            row.get("subscriber_email"),
-        )))
+        let task = Task {
+            newsletter_issue_id: row.get("newsletter_issue_id"),
+            subscriber_email: row.get("subscriber_email"),
+            unsubscribe_token: row.get("unsubscribe_token"),
+        };
+        Ok(Some((transaction, task)))
     } else {
         Ok(None)
     }

src/routes.rs

@@ -5,6 +5,7 @@ mod login;
 mod posts;
 mod subscriptions;
 mod subscriptions_confirm;
+mod unsubscribe;
 
 pub use admin::*;
 use askama::Template;
@@ -16,15 +17,38 @@ pub use health_check::*;
 pub use home::*;
 pub use login::*;
 pub use posts::*;
+use rand::{Rng, distr::Alphanumeric};
 use reqwest::StatusCode;
 pub use subscriptions::*;
 pub use subscriptions_confirm::*;
+pub use unsubscribe::*;
 
 use crate::{
     authentication::AuthError,
     templates::{InternalErrorTemplate, MessageTemplate, NotFoundTemplate},
 };
 
+pub fn generate_token() -> String {
+    let mut rng = rand::rng();
+    std::iter::repeat_with(|| rng.sample(Alphanumeric))
+        .map(char::from)
+        .take(25)
+        .collect()
+}
+
+fn error_chain_fmt(e: &impl std::error::Error, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+    writeln!(f, "{}", e)?;
+    let mut current = e.source();
+    while let Some(cause) = current {
+        write!(f, "Caused by:\n\t{}", cause)?;
+        current = cause.source();
+        if current.is_some() {
+            writeln!(f)?;
+        }
+    }
+    Ok(())
+}
+
 #[derive(thiserror::Error)]
 pub enum AppError {
     #[error("An unexpected error was encountered.")]

src/routes/admin/newsletters.rs

@@ -3,7 +3,7 @@ use crate::{
     idempotency::{IdempotencyKey, save_response, try_processing},
     routes::{AdminError, AppError},
     startup::AppState,
-    templates::MessageTemplate,
+    templates::{EmailTemplate, MessageTemplate, StandaloneEmailTemplate},
 };
 use anyhow::Context;
 use askama::Template;
@@ -27,8 +27,7 @@ pub struct BodyData {
 pub async fn insert_newsletter_issue(
     transaction: &mut Transaction<'static, Postgres>,
     title: &str,
-    text_content: &str,
-    html_content: &str,
+    email_template: &dyn EmailTemplate,
 ) -> Result<Uuid, sqlx::Error> {
     let newsletter_issue_id = Uuid::new_v4();
     let query = sqlx::query!(
@@ -40,8 +39,8 @@ pub async fn insert_newsletter_issue(
         "#,
         newsletter_issue_id,
         title,
-        text_content,
-        html_content
+        email_template.text(),
+        email_template.html(),
     );
     transaction.execute(query).await?;
     Ok(newsletter_issue_id)
@@ -56,9 +55,10 @@ pub async fn enqueue_delivery_tasks(
         r#"
         INSERT INTO issue_delivery_queue (
             newsletter_issue_id,
-            subscriber_email
+            subscriber_email,
+            unsubscribe_token
         )
-        SELECT $1, email
+        SELECT $1, email, unsubscribe_token
         FROM subscriptions
         WHERE status = 'confirmed'
         "#,
@@ -71,7 +71,9 @@ pub async fn enqueue_delivery_tasks(
 #[tracing::instrument(name = "Publishing a newsletter", skip(connection_pool, form))]
 pub async fn publish_newsletter(
     State(AppState {
-        connection_pool, ..
+        connection_pool,
+        base_url,
+        ..
     }): State<AppState>,
     Extension(AuthenticatedUser { user_id, .. }): Extension<AuthenticatedUser>,
     Form(form): Form<BodyData>,
@@ -90,7 +92,13 @@ pub async fn publish_newsletter(
         }
     };
 
-    let issue_id = insert_newsletter_issue(&mut transaction, &form.title, &form.text, &form.html)
+    let email_template = StandaloneEmailTemplate {
+        base_url: &base_url,
+        text_content: &form.text,
+        html_content: &form.html,
+    };
+
+    let issue_id = insert_newsletter_issue(&mut transaction, &form.title, &email_template)
         .await
         .context("Failed to store newsletter issue details.")?;
 

src/routes/admin/posts.rs

@@ -119,7 +119,5 @@ pub async fn create_newsletter(
         post_id,
         post_excerpt: "",
     };
-    let html_content = template.render().unwrap();
-    let text_content = template.text_version();
-    insert_newsletter_issue(transaction, post_title, &text_content, &html_content).await
+    insert_newsletter_issue(transaction, post_title, &template).await
 }

src/routes/subscriptions.rs

@@ -1,7 +1,7 @@
 use crate::{
     domain::{NewSubscriber, SubscriberEmail},
     email_client::EmailClient,
-    routes::AppError,
+    routes::{AppError, generate_token},
     startup::AppState,
     templates::MessageTemplate,
 };
@@ -13,35 +13,10 @@ use axum::{
     response::{Html, IntoResponse, Response},
 };
 use chrono::Utc;
-use rand::{Rng, distr::Alphanumeric};
 use serde::Deserialize;
 use sqlx::{Executor, Postgres, Transaction};
 use uuid::Uuid;
 
-fn generate_subscription_token() -> String {
-    let mut rng = rand::rng();
-    std::iter::repeat_with(|| rng.sample(Alphanumeric))
-        .map(char::from)
-        .take(25)
-        .collect()
-}
-
-pub fn error_chain_fmt(
-    e: &impl std::error::Error,
-    f: &mut std::fmt::Formatter,
-) -> std::fmt::Result {
-    writeln!(f, "{}", e)?;
-    let mut current = e.source();
-    while let Some(cause) = current {
-        write!(f, "Caused by:\n\t{}", cause)?;
-        current = cause.source();
-        if current.is_some() {
-            writeln!(f)?;
-        }
-    }
-    Ok(())
-}
-
 #[tracing::instrument(
     name = "Adding a new subscriber",
     skip(connection_pool, email_client, base_url, form),
@@ -69,7 +44,7 @@ pub async fn subscribe(
     let subscriber_id = insert_subscriber(&mut transaction, &new_subscriber)
         .await
         .context("Failed to insert new subscriber in the database.")?;
-    let subscription_token = generate_subscription_token();
+    let subscription_token = generate_token();
     store_token(&mut transaction, &subscription_token, &subscriber_id)
         .await
         .context("Failed to store the confirmation token for a new subscriber.")?;

src/routes/subscriptions_confirm.rs

@@ -1,4 +1,4 @@
-use crate::{startup::AppState, templates::ConfirmTemplate};
+use crate::{routes::generate_token, startup::AppState, templates::ConfirmTemplate};
 use askama::Template;
 use axum::{
     extract::{Query, State},
@@ -44,7 +44,8 @@ async fn confirm_subscriber(
     subscriber_id: &Uuid,
 ) -> Result<(), sqlx::Error> {
     sqlx::query!(
-        "UPDATE subscriptions SET status = 'confirmed' WHERE id = $1",
+        "UPDATE subscriptions SET status = 'confirmed', unsubscribe_token = $1 WHERE id = $2",
+        generate_token(),
         subscriber_id
     )
     .execute(connection_pool)

src/routes/unsubscribe.rs

@@ -0,0 +1,44 @@
+use crate::{
+    routes::AppError,
+    startup::AppState,
+    templates::{NotFoundTemplate, UnsubscribeTemplate},
+};
+use anyhow::Context;
+use askama::Template;
+use axum::{
+    extract::{Query, State},
+    response::{Html, IntoResponse, Response},
+};
+use reqwest::StatusCode;
+use sqlx::Executor;
+
+#[derive(serde::Deserialize)]
+pub struct UnsubQueryParams {
+    token: String,
+}
+
+pub async fn unsubscribe(
+    Query(UnsubQueryParams { token }): Query<UnsubQueryParams>,
+    State(AppState {
+        connection_pool, ..
+    }): State<AppState>,
+) -> Result<Response, AppError> {
+    let query = sqlx::query!(
+        "DELETE FROM subscriptions WHERE unsubscribe_token = $1",
+        token
+    );
+    let result = connection_pool
+        .execute(query)
+        .await
+        .context("Could not update subscriptions table.")?;
+
+    if result.rows_affected() == 0 {
+        Ok((
+            StatusCode::NOT_FOUND,
+            Html(NotFoundTemplate.render().unwrap()),
+        )
+            .into_response())
+    } else {
+        Ok(Html(UnsubscribeTemplate.render().unwrap()).into_response())
+    }
+}

src/startup.rs

@@ -127,6 +127,7 @@ pub fn app(
         .route("/health_check", get(health_check))
         .route("/subscriptions", post(subscribe))
         .route("/subscriptions/confirm", get(confirm))
+        .route("/unsubscribe", get(unsubscribe))
         .route("/posts", get(list_posts))
         .route("/posts/{post_id}", get(see_post))
         .nest("/admin", admin_routes)

src/templates.rs

@@ -50,6 +50,10 @@ pub struct ConfirmTemplate;
 #[template(path = "../templates/404.html")]
 pub struct NotFoundTemplate;
 
+#[derive(Template)]
+#[template(path = "../templates/unsubscribe.html")]
+pub struct UnsubscribeTemplate;
+
 #[derive(Template)]
 #[template(path = "../templates/email/new_post.html")]
 pub struct NewPostEmailTemplate<'a> {
@@ -59,8 +63,25 @@ pub struct NewPostEmailTemplate<'a> {
     pub post_excerpt: &'a str,
 }
 
-impl<'a> NewPostEmailTemplate<'a> {
-    pub fn text_version(&self) -> String {
+#[derive(Template)]
+#[template(path = "../templates/email/standalone.html")]
+pub struct StandaloneEmailTemplate<'a> {
+    pub base_url: &'a str,
+    pub html_content: &'a str,
+    pub text_content: &'a str,
+}
+
+pub trait EmailTemplate: Sync {
+    fn html(&self) -> String;
+    fn text(&self) -> String;
+}
+
+impl<'a> EmailTemplate for NewPostEmailTemplate<'a> {
+    fn html(&self) -> String {
+        self.render().unwrap()
+    }
+
+    fn text(&self) -> String {
         format!(
             r#"New post available!
 
@@ -82,10 +103,31 @@ Alphonse
 
 zero2prod - Building better backends with Rust
 Visit the blog: {}
-Unsubscribe: {}/unsubscribe
+Unsubscribe: {}/unsubscribe?token=UNSUBSCRIBE_TOKEN
 
 You're receiving this because you subscribed to the zero2prod newsletter."#,
             self.post_title, self.base_url, self.post_id, self.base_url, self.base_url,
         )
     }
 }
+
+impl<'a> EmailTemplate for StandaloneEmailTemplate<'a> {
+    fn html(&self) -> String {
+        self.render().unwrap()
+    }
+
+    fn text(&self) -> String {
+        format!(
+            r#"{}
+
+---
+
+zero2prod - Building better backends with Rust
+Visit the blog: {}
+Unsubscribe: {}/unsubscribe?token=UNSUBSCRIBE_TOKEN
+
+You're receiving this because you subscribed to the zero2prod newsletter."#,
+            self.text_content, self.base_url, self.base_url
+        )
+    }
+}

templates/email/base.html

@@ -0,0 +1,145 @@
+<!DOCTYPE html>
+<html lang="en">
+  <head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <meta name="description" content="zero2prod">
+    <meta name="keywords" content="rust backend programming">
+    <title>
+      {% block title %}Updates{% endblock %}
+    - zero2prod</title>
+    <style>
+body {
+  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
+  line-height: 1.6;
+  color: #374151;
+  margin: 0;
+  padding: 0;
+  background-color: #f9fafb;
+}
+.container {
+  max-width: 600px;
+  margin: 0 auto;
+  background-color: #ffffff;
+  border-radius: 8px;
+  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
+}
+.header {
+  background: linear-gradient(135deg, #3b82f6, #6366f1);
+  color: white;
+  padding: 32px 24px;
+  text-align: center;
+}
+.header h1 {
+  margin: 0;
+  font-size: 24px;
+  font-weight: 700;
+}
+.header p {
+  margin: 8px 0 0 0;
+  opacity: 0.9;
+  font-size: 16px;
+}
+.content {
+  padding: 32px 24px;
+}
+.post-preview {
+  background-color: #f8fafc;
+  border-left: 4px solid #3b82f6;
+  padding: 24px;
+  margin: 24px 0;
+  border-radius: 0 6px 6px 0;
+}
+.post-title {
+  font-size: 20px;
+  font-weight: 600;
+  color: #1f2937;
+  margin: 0 0 12px 0;
+  line-height: 1.3;
+}
+.post-excerpt {
+  color: #6b7280;
+  margin: 0;
+  font-size: 15px;
+}
+.cta-button {
+  display: inline-block;
+  background: linear-gradient(135deg, #3b82f6, #6366f1);
+  color: white;
+  padding: 14px 28px;
+  text-decoration: none;
+  border-radius: 6px;
+  font-weight: 600;
+  margin: 24px 0;
+  transition: transform 0.2s;
+}
+.cta-button:hover {
+  transform: translateY(-1px);
+}
+.footer {
+  background-color: #f8fafc;
+  padding: 24px;
+  border-top: 1px solid #e5e7eb;
+  text-align: center;
+}
+.footer p {
+  margin: 0;
+  font-size: 14px;
+  color: #6b7280;
+}
+.footer a {
+  color: #3b82f6;
+  text-decoration: none;
+}
+.unsubscribe {
+  font-size: 12px;
+  color: #9ca3af;
+  margin-top: 16px;
+}
+@media only screen and (max-width: 600px) {
+  .container {
+    margin: 0;
+    border-radius: 0;
+  }
+  .header,
+  .content,
+  .footer {
+    padding: 24px 16px;
+  }
+  .header h1 {
+    font-size: 20px;
+  }
+  .post-preview {
+    padding: 16px;
+    margin: 16px 0;
+  }
+  .post-title {
+    font-size: 18px;
+  }
+}
+    </style>
+  </head>
+  <body>
+    <div class="container">
+      <div class="header">
+        <h1>Updates from zero2prod</h1>
+        <p>Fresh insights on Rust backend development</p>
+      </div>
+      <div class="content">
+        {% block content %}{% endblock %}
+      </div>
+    </div>
+    <div class="footer">
+      <p>
+        <strong>zero2prod</strong>
+        <br>
+        Building better backends with Rust
+      </p>
+      <p>
+        <a href="{{ base_url }}">Visit the blog</a> •
+        <a href="{{ base_url }}/unsubscribe?token=UNSUBSCRIBE_TOKEN">Unsubscribe</a>
+      </p>
+      <p class="unsubscribe">You're receiving this because you subscribed to the zero2prod newsletter.</p>
+    </div>
+  </body>
+</html>

templates/email/new_post.html

@@ -1,157 +1,20 @@
-<!DOCTYPE html>
-<html lang="en">
-    <head>
-        <meta charset="UTF-8">
-        <meta name="viewport" content="width=device-width, initial-scale=1.0">
-        <meta name="description" content="zero2prod newsletter" />
-        <meta name="keywords" content="newsletter, rust, axum, htmx" />
-        <title>{{ post_title }}</title>
-        <style>
-        body {
-            font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
-            line-height: 1.6;
-            color: #374151;
-            margin: 0;
-            padding: 0;
-            background-color: #f9fafb;
-        }
-        .container {
-            max-width: 600px;
-            margin: 0 auto;
-            background-color: #ffffff;
-            border-radius: 8px;
-            box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
-        }
-        .header {
-            background: linear-gradient(135deg, #3b82f6, #6366f1);
-            color: white;
-            padding: 32px 24px;
-            text-align: center;
-        }
-        .header h1 {
-            margin: 0;
-            font-size: 24px;
-            font-weight: 700;
-        }
-        .header p {
-            margin: 8px 0 0 0;
-            opacity: 0.9;
-            font-size: 16px;
-        }
-        .content {
-            padding: 32px 24px;
-        }
-        .post-preview {
-            background-color: #f8fafc;
-            border-left: 4px solid #3b82f6;
-            padding: 24px;
-            margin: 24px 0;
-            border-radius: 0 6px 6px 0;
-        }
-        .post-title {
-            font-size: 20px;
-            font-weight: 600;
-            color: #1f2937;
-            margin: 0 0 12px 0;
-            line-height: 1.3;
-        }
-        .post-excerpt {
-            color: #6b7280;
-            margin: 0;
-            font-size: 15px;
-        }
-        .cta-button {
-            display: inline-block;
-            background: linear-gradient(135deg, #3b82f6, #6366f1);
-            color: white;
-            padding: 14px 28px;
-            text-decoration: none;
-            border-radius: 6px;
-            font-weight: 600;
-            margin: 24px 0;
-            transition: transform 0.2s;
-        }
-        .cta-button:hover {
-            transform: translateY(-1px);
-        }
-        .footer {
-            background-color: #f8fafc;
-            padding: 24px;
-            border-top: 1px solid #e5e7eb;
-            text-align: center;
-        }
-        .footer p {
-            margin: 0;
-            font-size: 14px;
-            color: #6b7280;
-        }
-        .footer a {
-            color: #3b82f6;
-            text-decoration: none;
-        }
-        .unsubscribe {
-            font-size: 12px;
-            color: #9ca3af;
-            margin-top: 16px;
-        }
-        
-        @media only screen and (max-width: 600px) {
-            .container {
-                margin: 0;
-                border-radius: 0;
-            }
-            .header, .content, .footer {
-                padding: 24px 16px;
-            }
-            .header h1 {
-                font-size: 20px;
-            }
-            .post-preview {
-                padding: 16px;
-                margin: 16px 0;
-            }
-            .post-title {
-                font-size: 18px;
-            }
-        }
-        </style>
-    </head>
-    <body>
-        <div class="container">
-            <div class="header">
-                <h1>A new post is available!</h1>
-                <p>Fresh insights on Rust backend development</p>
-            </div>
-            <div class="content">
-                <p>Hello there!</p>
-                <p>I just published a new post that I think you'll find interesting:</p>
-                <div class="post-preview">
-                    <h2 class="post-title">{{ post_title }}</h2>
-                    {% if !post_excerpt.is_empty() %}<p class="post-excerpt">{{ post_excerpt }}</p>{% endif %}
-                </div>
-                <a href="{{ base_url }}/posts/{{ post_id }}" class="cta-button">Read the full post →</a>
-                <p>
-                    This post covers practical insights and real-world examples that I hope will be valuable for your backend development journey.
-                </p>
-                <p>Thanks for being a subscriber!</p>
-                <p>
-                    Best regards,
-                    <br>
-                    <strong>Alphonse</strong>
-                </p>
-            </div>
-            <div class="footer">
-                <p>
-                    <strong>zero2prod</strong>
-                    <br>
-                    Building better backends with Rust
-                </p>
-                <p>
-                    <a href="{{ base_url }}">Visit the blog</a> •
-                    <a href="{{ base_url }}/unsubscribe">Unsubscribe</a>
-                </p>
-                <p class="unsubscribe">You're receiving this because you subscribed to the zero2prod newsletter.</p>
-            </div>
-        </div>
-    </body>
-</html>
+{% extends "base.html" %}
+{% block title %}New post available: {{ post_title }}{% endblock %}
+{% block content %}
+    <p>Hello there!</p>
+    <p>I just published a new post that I think you'll find interesting:</p>
+    <div class="post-preview">
+        <h2 class="post-title">{{ post_title }}</h2>
+        {% if !post_excerpt.is_empty() %}<p class="post-excerpt">{{ post_excerpt }}</p>{% endif %}
+    </div>
+    <a href="{{ base_url }}/posts/{{ post_id }}" class="cta-button">Read the full post →</a>
+    <p>
+        This post covers practical insights and real-world examples that I hope will be valuable for your backend development journey.
+    </p>
+    <p>Thanks for being a subscriber!</p>
+    <p>
+        Best regards,
+        <br>
+        <strong>Alphonse</strong>
+    </p>
+{% endblock %}

templates/email/standalone.html

@@ -0,0 +1,2 @@
+{% extends "base.html" %}
+{% block content %}{{ html_content }}{% endblock %}

templates/unsubscribe.html

@@ -0,0 +1,45 @@
+{% extends "base.html" %}
+{% block title %}Unsubscribed{% endblock %}
+{% block content %}
+    <div class="flex-1 flex items-center justify-center">
+        <div class="max-w-4xl mx-auto text-center">
+            <div class="mb-8">
+                <div class="w-24 h-24 bg-amber-100 rounded-full flex items-center justify-center mx-auto mb-6">
+                    <svg class="w-12 h-12 text-amber-600"
+                         fill="none"
+                         viewBox="0 0 24 24"
+                         stroke="currentColor">
+                        <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M7 7h.01M7 3h5c.512 0 1.024.195 1.414.586l7 7a2 2 0 010 2.828l-7 7a2 2 0 01-2.828 0l-7-7A1.994 1.994 0 013 12V7a4 4 0 014-4z" />
+                    </svg>
+                </div>
+                <h1 class="text-4xl font-bold text-gray-800 mb-4">Good bye, old friend!</h1>
+                <h2 class="text-xl font-medium text-gray-600 mb-6">You've successfully unsubscribed</h2>
+                <p class="text-gray-600 mb-8 max-w-2xl mx-auto">
+                    Your email has been removed from the database. You won't receive emails anymore. If you change your mind, you are welcome back any time!
+                </p>
+                <div class="flex flex-col sm:flex-row gap-4 justify-center items-center">
+                    <a href="/"
+                       class="bg-blue-600 text-white hover:bg-blue-700 px-6 py-3 rounded-md font-medium transition-colors flex items-center">
+                        <svg class="w-4 h-4 mr-2"
+                             fill="none"
+                             viewBox="0 0 24 24"
+                             stroke="currentColor">
+                            <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M3 12l2-2m0 0l7-7 7 7M5 10v10a1 1 0 001 1h3m10-11l2 2m-2-2v10a1 1 0 01-1 1h-3m-6 0a1 1 0 001-1v-4a1 1 0 011-1h2a1 1 0 011 1v4a1 1 0 001 1m-6 0h6" />
+                        </svg>
+                        Home
+                    </a>
+                    <a href="/posts"
+                       class="bg-white text-gray-700 hover:text-blue-600 hover:bg-blue-50 border border-gray-300 px-6 py-3 rounded-md font-medium transition-colors flex items-center">
+                        <svg class="w-4 h-4 mr-2"
+                             fill="none"
+                             viewBox="0 0 24 24"
+                             stroke="currentColor">
+                            <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M19 20H5a2 2 0 01-2-2V6a2 2 0 012-2h10a2 2 0 012 2v1m2 13a2 2 0 01-2-2V7m2 13a2 2 0 002-2V9a2 2 0 00-2-2h-2m-4-3H9M7 16h6M7 8h6v4H7V8z" />
+                        </svg>
+                        Posts
+                    </a>
+                </div>
+            </div>
+        </div>
+    </div>
+{% endblock %}

tests/api/helpers.rs

@@ -3,7 +3,7 @@ use argon2::{
     password_hash::{SaltString, rand_core::OsRng},
 };
 use fake::{Fake, faker::internet::en::SafeEmail};
-use linkify::LinkFinder;
+use linkify::{Link, LinkFinder};
 use once_cell::sync::Lazy;
 use sqlx::{Connection, Executor, PgConnection, PgPool};
 use uuid::Uuid;
@@ -169,16 +169,13 @@ impl TestApp {
         }
     }
 
-    pub fn get_confirmation_links(&self, request: &wiremock::Request) -> ConfirmationLinks {
+    pub fn get_unsubscribe_links(&self, request: &wiremock::Request) -> ConfirmationLinks {
         let body: serde_json::Value = serde_json::from_slice(&request.body).unwrap();
         let get_link = |s: &str| {
-            let links: Vec<_> = LinkFinder::new()
-                .links(s)
-                .filter(|l| *l.kind() == linkify::LinkKind::Url)
-                .collect();
-            assert_eq!(links.len(), 1);
-            let raw_link = links[0].as_str();
-            let mut confirmation_link = reqwest::Url::parse(raw_link).unwrap();
+            let links = get_links(s);
+            assert!(!links.is_empty());
+            let mut confirmation_link =
+                reqwest::Url::parse(links.last().unwrap().as_str()).unwrap();
             assert_eq!(confirmation_link.host_str().unwrap(), "127.0.0.1");
             confirmation_link.set_port(Some(self.port)).unwrap();
             confirmation_link
@@ -189,6 +186,33 @@ impl TestApp {
         ConfirmationLinks { html, text }
     }
 
+    pub fn get_confirmation_links(&self, request: &wiremock::Request) -> ConfirmationLinks {
+        let body: serde_json::Value = serde_json::from_slice(&request.body).unwrap();
+        let get_link = |s: &str| {
+            let links = get_links(s);
+            assert_eq!(links.len(), 1);
+            let mut confirmation_link = reqwest::Url::parse(links[0].as_str()).unwrap();
+            assert_eq!(confirmation_link.host_str().unwrap(), "127.0.0.1");
+            confirmation_link.set_port(Some(self.port)).unwrap();
+            confirmation_link
+        };
+
+        let html = get_link(body["html"].as_str().unwrap());
+        let text = get_link(body["text"].as_str().unwrap());
+        ConfirmationLinks { html, text }
+    }
+
+    pub async fn get_unsubscribe(&self, unsubscribe_token: String) -> reqwest::Response {
+        self.api_client
+            .get(format!(
+                "{}/unsubscribe?token={}",
+                &self.address, unsubscribe_token
+            ))
+            .send()
+            .await
+            .expect("Failed to execute request")
+    }
+
     pub async fn get_admin_dashboard(&self) -> reqwest::Response {
         self.api_client
             .get(format!("{}/admin/dashboard", &self.address))
@@ -307,3 +331,29 @@ pub fn assert_is_redirect_to(response: &reqwest::Response, location: &str) {
 pub fn when_sending_an_email() -> MockBuilder {
     Mock::given(path("/email")).and(method("POST"))
 }
+
+pub fn fake_newsletter_body() -> serde_json::Value {
+    serde_json::json!({
+        "title": "Newsletter title",
+        "text": "Newsletter body as plain text",
+        "html": "<p>Newsletter body as HTML</p>",
+        "idempotency_key": Uuid::new_v4().to_string(),
+
+    })
+}
+
+pub fn fake_post_body() -> serde_json::Value {
+    serde_json::json!({
+        "title": "Post title",
+        "content": "Post content",
+        "idempotency_key": Uuid::new_v4().to_string(),
+
+    })
+}
+
+pub fn get_links(s: &'_ str) -> Vec<Link<'_>> {
+    LinkFinder::new()
+        .links(s)
+        .filter(|l| *l.kind() == linkify::LinkKind::Url)
+        .collect()
+}

tests/api/main.rs

@@ -7,3 +7,4 @@ mod newsletters;
 mod posts;
 mod subscriptions;
 mod subscriptions_confirm;
+mod unsubscribe;

tests/api/unsubscribe.rs

@@ -0,0 +1,129 @@
+use wiremock::ResponseTemplate;
+
+use crate::helpers::{TestApp, fake_newsletter_body, fake_post_body, when_sending_an_email};
+
+#[tokio::test]
+async fn subscriber_can_unsubscribe() {
+    let app = TestApp::spawn().await;
+    app.create_confirmed_subscriber().await;
+    app.admin_login().await;
+
+    when_sending_an_email()
+        .respond_with(ResponseTemplate::new(200))
+        .expect(1)
+        .mount(&app.email_server)
+        .await;
+
+    app.post_newsletters(&fake_newsletter_body()).await;
+    app.dispatch_all_pending_emails().await;
+
+    let record = sqlx::query!("SELECT unsubscribe_token FROM subscriptions")
+        .fetch_one(&app.connection_pool)
+        .await
+        .expect("Failed to fetch saved token");
+
+    let response = app
+        .get_unsubscribe(
+            record
+                .unsubscribe_token
+                .expect("Confirmed subscriber should have a valid unsubscribe token"),
+        )
+        .await;
+
+    assert_eq!(response.status().as_u16(), 200);
+    let html_fragment = response.text().await.unwrap();
+    assert!(html_fragment.contains("Good bye, old friend"));
+
+    let record = sqlx::query!("SELECT email FROM subscriptions")
+        .fetch_optional(&app.connection_pool)
+        .await
+        .expect("Failed to fetch subscription table");
+
+    assert!(record.is_none());
+
+    when_sending_an_email()
+        .respond_with(ResponseTemplate::new(200))
+        .expect(0)
+        .mount(&app.email_server)
+        .await;
+
+    app.post_newsletters(&fake_newsletter_body()).await;
+    app.dispatch_all_pending_emails().await;
+}
+
+#[tokio::test]
+async fn a_valid_unsubscribe_link_is_present_in_new_post_email_notifications() {
+    let app = TestApp::spawn().await;
+    app.create_confirmed_subscriber().await;
+    app.admin_login().await;
+
+    when_sending_an_email()
+        .respond_with(ResponseTemplate::new(200))
+        .expect(1)
+        .mount(&app.email_server)
+        .await;
+
+    app.post_create_post(&fake_post_body()).await;
+    app.dispatch_all_pending_emails().await;
+    let email_request = app
+        .email_server
+        .received_requests()
+        .await
+        .unwrap()
+        .pop()
+        .unwrap();
+    let unsubscribe_links = app.get_unsubscribe_links(&email_request);
+    reqwest::get(unsubscribe_links.html)
+        .await
+        .unwrap()
+        .error_for_status()
+        .unwrap();
+
+    let record = sqlx::query!("SELECT email FROM subscriptions")
+        .fetch_optional(&app.connection_pool)
+        .await
+        .expect("Failed to fetch subscription table");
+
+    assert!(record.is_none());
+}
+
+#[tokio::test]
+async fn a_valid_unsubscribe_link_is_present_in_emails_manually_sent() {
+    let app = TestApp::spawn().await;
+    app.create_confirmed_subscriber().await;
+    app.admin_login().await;
+
+    when_sending_an_email()
+        .respond_with(ResponseTemplate::new(200))
+        .expect(1)
+        .mount(&app.email_server)
+        .await;
+
+    app.post_newsletters(&fake_newsletter_body()).await;
+    app.dispatch_all_pending_emails().await;
+    let email_request = app
+        .email_server
+        .received_requests()
+        .await
+        .unwrap()
+        .pop()
+        .unwrap();
+    let unsubscribe_links = app.get_unsubscribe_links(&email_request);
+    reqwest::get(unsubscribe_links.html)
+        .await
+        .unwrap()
+        .error_for_status()
+        .unwrap();
+}
+
+#[tokio::test]
+async fn an_invalid_unsubscribe_token_is_rejected() {
+    let app = TestApp::spawn().await;
+    app.create_confirmed_subscriber().await;
+
+    let response = reqwest::get(format!("{}/unsubscribe?token=invalid", app.address))
+        .await
+        .unwrap();
+
+    assert_eq!(response.status().as_u16(), 404);
+}