A new env variable

BACKEND_PORT for the port of the backend

backend/src/env.rs

@@ -1,12 +1,13 @@
 /// Environment configuration for the application.
 ///
 /// Loads required configuration from environment variables at startup.
-/// All variables must be present or the application will panic.
+/// All variables must be present or the application will panic during [`Env::load`].
+/// Used by [`AppState`](crate::AppState) for configuring JWT signing and CORS.
 ///
 /// # Fields
-/// - `db_url`: PostgreSQL database connection URL.
-/// - `token_secret`: Secret key used to sign and verify JWT tokens.
-/// - `origin`: Frontend origin URL for CORS policy.
+/// - `db_url`: PostgreSQL database connection URL
+/// - `token_secret`: Secret key used to sign and verify [`Claims`](crate::models::Claims) in JWT tokens
+/// - `origin`: Frontend origin URL for CORS policy configuration
 ///
 /// # Required Environment Variables
 /// - `DATABASE_URL`: PostgreSQL connection string (e.g., `postgresql://user:pass@localhost/dbname`)
@@ -20,26 +21,38 @@ pub struct Env {
     pub token_secret: String,
     /// Frontend origin URL for CORS policy
     pub origin: String,
+    /// Backend port number
+    pub backend_port: String,
 }
 
 impl Env {
     /// Loads environment configuration from system environment variables.
     ///
-    /// Panics if any required variable is missing.
+    /// Reads `DATABASE_URL`, `TOKEN_SECRET`, and `ORIGIN` from the environment and returns
+    /// a configured [`Env`] instance. Used during server initialization in the `main` function.
+    ///
+    /// # Panics
+    /// If any required variable is missing (DATABASE_URL, TOKEN_SECRET, or ORIGIN).
     ///
     /// # Example
     /// ```ignore
     /// let env = Env::load();
     /// // Environment must have DATABASE_URL, TOKEN_SECRET, and ORIGIN set
+    /// let app_state = AppState {
+    ///     db: pool,
+    ///     env,
+    /// };
     /// ```
     pub fn load() -> Env {
         let db_url = std::env::var("DATABASE_URL").expect("DATABASE_URL must be set");
         let token_secret = std::env::var("TOKEN_SECRET").expect("TOKEN_SECRET must be set");
         let origin = std::env::var("ORIGIN").expect("ORIGIN must be set");
+        let backend_port = std::env::var("BACKEND_PORT").expect("BACKEND_PORT must be set");
         Env {
             db_url,
             token_secret,
             origin,
+            backend_port,
         }
     }
 }