docs: clarify documentation

This commit removes the `Opportunistic` value from the struct `StartTls`.
This value was strictly equivalent to `Always` and could potentially
cause confusion.

.github/workflows/action.yml

@@ -40,9 +40,21 @@ jobs:
           authToken: '${{ secrets.CACHIX_AUTH_TOKEN }}'
           skipPush: ${{ github.event_name == 'pull_request' }}
 
+      - name: Format Check
+        shell: bash -c "nix develop --no-pure-eval --accept-flake-config --command {0}"
+        run: just format-check
+
+      - name: Audit
+        shell: bash -c "nix develop --no-pure-eval --accept-flake-config --command {0}"
+        run: just audit
+
+      - name: Lint
+        shell: bash -c "nix develop --no-pure-eval --accept-flake-config --command {0}"
+        run: just lint-report
+
       - name: Coverage
-        run: |
+        shell: bash -c "nix develop --no-pure-eval --accept-flake-config --command {0}"
-            nix develop --no-pure-eval --accept-flake-config --command just coverage
+        run: just coverage-ci
 
       - name: Sonar analysis
         uses: SonarSource/sonarqube-scan-action@v6

README.md

@@ -321,7 +321,7 @@ backend/
 
 The contact form supports multiple SMTP configurations:
 - **Implicit TLS (SMTPS)** - typically port 465
-- **STARTTLS (Always/Opportunistic)** - typically port 587
+- **STARTTLS (Always)** - typically port 587
 - **Unencrypted** (for local dev) - with or without authentication
 
 The `SmtpTransport` is built dynamically from `EmailSettings` based on

src/lib.rs

@@ -24,7 +24,7 @@ pub mod startup;
 /// Logging and tracing setup
 pub mod telemetry;
 
-type MaybeListener = Option<poem::listener::TcpListener<String>>;
+type MaybeListener = Option<std::net::TcpListener>;
 
 fn prepare(listener: MaybeListener) -> startup::Application {
     dotenvy::dotenv().ok();
@@ -70,11 +70,8 @@ pub async fn run(listener: MaybeListener) -> Result<(), std::io::Error> {
 }
 
 #[cfg(test)]
-fn make_random_tcp_listener() -> poem::listener::TcpListener<String> {
+fn make_random_tcp_listener() -> std::net::TcpListener {
-    let tcp_listener =
+    std::net::TcpListener::bind("127.0.0.1:0").expect("Failed to bind a random TCP listener")
-        std::net::TcpListener::bind("127.0.0.1:0").expect("Failed to bind a random TCP listener");
-    let port = tcp_listener.local_addr().unwrap().port();
-    poem::listener::TcpListener::bind(format!("127.0.0.1:{port}"))
 }
 
 #[cfg(test)]

src/route/contact/mod.rs

@@ -62,7 +62,7 @@ impl TryFrom<&EmailSettings> for SmtpTransport {
                         Ok(builder.credentials(creds).build())
                     }
                 }
-                Starttls::Opportunistic | Starttls::Always => {
+                Starttls::Always => {
                     // STARTTLS - typically port 587
                     tracing::event!(target: "backend::contact", tracing::Level::DEBUG, "Using STARTTLS");
                     let creds = Credentials::new(settings.user.clone(), settings.password.clone());
@@ -429,23 +429,6 @@ mod tests {
         assert!(result.is_ok());
     }
 
-    #[test]
-    fn smtp_transport_starttls_opportunistic() {
-        let settings = EmailSettings {
-            host: "smtp.example.com".to_string(),
-            port: 587,
-            user: "user@example.com".to_string(),
-            password: "password".to_string(),
-            from: "from@example.com".to_string(),
-            recipient: "to@example.com".to_string(),
-            tls: false,
-            starttls: Starttls::Opportunistic,
-        };
-
-        let result = SmtpTransport::try_from(&settings);
-        assert!(result.is_ok());
-    }
-
     #[test]
     fn smtp_transport_no_encryption_with_credentials() {
         let settings = EmailSettings {

src/settings.rs

@@ -163,8 +163,9 @@ impl EmailSettings {
     ///
     /// # Errors
     ///
-    /// Returns a `ContactError` if the email address in the `from` field cannot be parsed
+    /// Returns a `ContactError` if the email address in the `from`
-    /// into a valid mailbox. This can occur if:
+    /// field of `recipient` cannot be parsed into a valid mailbox.
+    /// This can occur if:
     /// - The email address format is invalid
     /// - The email address contains invalid characters
     /// - The email address structure is malformed
@@ -196,8 +197,6 @@ pub enum Starttls {
     /// Never use STARTTLS (unencrypted connection)
     #[default]
     Never,
-    /// Use STARTTLS if available (opportunistic encryption)
-    Opportunistic,
     /// Always use STARTTLS (required encryption)
     Always,
 }
@@ -208,10 +207,9 @@ impl TryFrom<&str> for Starttls {
     fn try_from(value: &str) -> Result<Self, Self::Error> {
         match value.to_lowercase().as_str() {
             "off" | "no" | "never" => Ok(Self::Never),
-            "opportunistic" => Ok(Self::Opportunistic),
             "yes" | "always" => Ok(Self::Always),
             other => Err(format!(
-                "{other} is not a supported option. Use either `yes`, `no`, or `opportunistic`"
+                "{other} is not a supported option. Use either `yes` or `no`"
             )),
         }
     }
@@ -234,7 +232,6 @@ impl std::fmt::Display for Starttls {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         let self_str = match self {
             Self::Never => "never",
-            Self::Opportunistic => "opportunistic",
             Self::Always => "always",
         };
         write!(f, "{self_str}")
@@ -252,7 +249,7 @@ impl<'de> serde::Deserialize<'de> for Starttls {
             type Value = Starttls;
 
             fn expecting(&self, formatter: &mut std::fmt::Formatter) -> std::fmt::Result {
-                formatter.write_str("a string or boolean representing STARTTLS setting (e.g., 'yes', 'no', 'opportunistic', true, false)")
+                formatter.write_str("a string or boolean representing STARTTLS setting (e.g., 'yes', 'no', true, false)")
             }
 
             fn visit_str<E>(self, value: &str) -> Result<Starttls, E>
@@ -434,13 +431,6 @@ mod tests {
         assert_eq!(result, Starttls::Always);
     }
 
-    #[test]
-    fn startls_deserialize_from_string_opportunistic() {
-        let json = r#""opportunistic""#;
-        let result: Starttls = serde_json::from_str(json).unwrap();
-        assert_eq!(result, Starttls::Opportunistic);
-    }
-
     #[test]
     fn startls_deserialize_from_bool() {
         let json = "true";
@@ -482,18 +472,6 @@ mod tests {
         assert_eq!(Starttls::try_from("Yes").unwrap(), Starttls::Always);
     }
 
-    #[test]
-    fn startls_try_from_str_opportunistic() {
-        assert_eq!(
-            Starttls::try_from("opportunistic").unwrap(),
-            Starttls::Opportunistic
-        );
-        assert_eq!(
-            Starttls::try_from("OPPORTUNISTIC").unwrap(),
-            Starttls::Opportunistic
-        );
-    }
-
     #[test]
     fn startls_try_from_str_invalid() {
         let result = Starttls::try_from("invalid");
@@ -517,14 +495,6 @@ mod tests {
         );
     }
 
-    #[test]
-    fn startls_try_from_string_opportunistic() {
-        assert_eq!(
-            Starttls::try_from("opportunistic".to_string()).unwrap(),
-            Starttls::Opportunistic
-        );
-    }
-
     #[test]
     fn startls_try_from_string_invalid() {
         let result = Starttls::try_from("invalid".to_string());
@@ -553,12 +523,6 @@ mod tests {
         assert_eq!(startls.to_string(), "always");
     }
 
-    #[test]
-    fn startls_display_opportunistic() {
-        let startls = Starttls::Opportunistic;
-        assert_eq!(startls.to_string(), "opportunistic");
-    }
-
     #[test]
     fn rate_limit_settings_default() {
         let settings = RateLimitSettings::default();

src/startup.rs

@@ -6,6 +6,7 @@
 //! - Configuring CORS
 //! - Starting the HTTP server
 
+use poem::listener::{Listener, TcpAcceptor};
 use poem::middleware::{AddDataEndpoint, Cors, CorsEndpoint};
 use poem::{EndpointExt, Route};
 use poem_openapi::OpenApiService;
@@ -19,10 +20,21 @@ use crate::{
 
 use crate::middleware::rate_limit::RateLimitEndpoint;
 
-type Server = poem::Server<poem::listener::TcpListener<String>, std::convert::Infallible>;
+type Server = poem::Server<poem::listener::BoxListener, std::convert::Infallible>;
+
 /// The configured application with rate limiting, CORS, and settings data.
 pub type App = AddDataEndpoint<CorsEndpoint<RateLimitEndpoint<Route>>, Settings>;
 
+struct PreBoundListener(std::net::TcpListener);
+
+impl Listener for PreBoundListener {
+    type Acceptor = TcpAcceptor;
+
+    async fn into_acceptor(self) -> std::io::Result<Self::Acceptor> {
+        TcpAcceptor::from_std(self.0)
+    }
+}
+
 /// Application builder that holds the server configuration before running.
 pub struct Application {
     server: Server,
@@ -135,30 +147,33 @@ impl Application {
 
     fn setup_server(
         settings: &Settings,
-        tcp_listener: Option<poem::listener::TcpListener<String>>,
+        tcp_listener: Option<std::net::TcpListener>,
-    ) -> Server {
+    ) -> (Server, u16, String) {
-        let tcp_listener = tcp_listener.unwrap_or_else(|| {
+        tcp_listener.map_or_else(
-            let address = format!(
+            || {
-                "{}:{}",
+                let port = settings.application.port;
-                settings.application.host, settings.application.port
+                let host = settings.application.host.clone();
-            );
+                let address = format!("{host}:{port}");
-            poem::listener::TcpListener::bind(address)
+                let server = poem::Server::new(poem::listener::TcpListener::bind(address).boxed());
-        });
+                (server, port, host)
-        poem::Server::new(tcp_listener)
+            },
+            |listener| {
+                let addr = listener.local_addr().expect("Failed to get bound address");
+                let port = addr.port();
+                let host = addr.ip().to_string();
+                let server = poem::Server::new(PreBoundListener(listener).boxed());
+                (server, port, host)
+            },
+        )
     }
 
     /// Builds a new application with the given settings and optional TCP listener.
     ///
     /// If no listener is provided, one will be created based on the settings.
     #[must_use]
-    pub fn build(
+    pub fn build(settings: Settings, tcp_listener: Option<std::net::TcpListener>) -> Self {
-        settings: Settings,
+        let (server, port, host) = Self::setup_server(&settings, tcp_listener);
-        tcp_listener: Option<poem::listener::TcpListener<String>>,
-    ) -> Self {
-        let port = settings.application.port;
-        let host = settings.application.host.clone();
         let app = Self::setup_app(&settings);
-        let server = Self::setup_server(&settings, tcp_listener);
         Self {
             server,
             app,
@@ -243,13 +258,11 @@ mod tests {
     #[test]
     fn application_with_custom_listener() {
         let settings = create_test_settings();
-        let tcp_listener =
+        let listener =
             std::net::TcpListener::bind("127.0.0.1:0").expect("Failed to bind random port");
-        let port = tcp_listener.local_addr().unwrap().port();
+        let expected_port = listener.local_addr().unwrap().port();
-        let listener = poem::listener::TcpListener::bind(format!("127.0.0.1:{port}"));
-
         let app = Application::build(settings, Some(listener));
         assert_eq!(app.host(), "127.0.0.1");
-        assert_eq!(app.port(), 8080);
+        assert_eq!(app.port(), expected_port);
     }
 }