Improve testability and remove boxing

Leverage generics to remove the extra heap allocation for the response
handlers using Dao's. Also moved some of the environment variables to
app state to allow for easier testing.

src/auth.rs

@@ -1,4 +1,4 @@
-use actix_web::{post, Responder};
+use actix_web::Responder;
 use actix_web::{
     web::{self, Json},
     HttpResponse,
@@ -12,10 +12,10 @@ use crate::{
     database::UserDao,
 };
 
-#[post("/register")]
-async fn register(
+#[allow(dead_code)]
+async fn register<D: UserDao>(
     user: Json<CreateAccountRequest>,
-    user_dao: web::Data<Box<dyn UserDao>>,
+    user_dao: web::Data<D>,
 ) -> impl Responder {
     if !user.username.is_empty() && user.password.len() > 5 && user.password == user.confirmation {
         if user_dao.user_exists(&user.username) {
@@ -30,10 +30,7 @@ async fn register(
     }
 }
 
-pub async fn login(
-    creds: Json<LoginRequest>,
-    user_dao: web::Data<Box<dyn UserDao>>,
-) -> HttpResponse {
+pub async fn login<D: UserDao>(creds: Json<LoginRequest>, user_dao: web::Data<D>) -> HttpResponse {
     debug!("Logging in: {}", creds.username);
 
     if let Some(user) = user_dao.get_user(&creds.username, &creds.password) {
@@ -74,7 +71,7 @@ mod tests {
             password: "pass".to_string(),
         });
 
-        let response = login(j, web::Data::new(Box::new(dao))).await;
+        let response = login::<TestUserDao>(j, web::Data::new(dao)).await;
 
         assert_eq!(response.status(), 200);
     }
@@ -89,7 +86,7 @@ mod tests {
             password: "password".to_string(),
         });
 
-        let response = login(j, web::Data::new(Box::new(dao))).await;
+        let response = login::<TestUserDao>(j, web::Data::new(dao)).await;
 
         assert_eq!(response.status(), 200);
         let response_text: String = response.read_to_str();
@@ -107,7 +104,7 @@ mod tests {
             password: "password".to_string(),
         });
 
-        let response = login(j, web::Data::new(Box::new(dao))).await;
+        let response = login::<TestUserDao>(j, web::Data::new(dao)).await;
 
         assert_eq!(response.status(), 404);
     }