Refactor database URL tests to use temp_env with multiple variables and improve clarity

crates/backend/src/main.rs

@@ -92,31 +92,31 @@ fn build_database_url() -> String {
 #[cfg(test)]
 mod tests {
     use super::*;
-    use temp_env::with_vars;
+    use temp_env::{with_vars, with_vars_unset};
 
     #[test]
     fn build_database_url_with_defaults() {
-        temp_env::with_vars([("DB_HOST", None::<&str>)], || {
-            // Was sieht die direkte Umgebung? (Sollte Err sein)
-            println!(
-                "Inside temp_env (unset): std::env::var(\"DB_HOST\") is {:?}",
-                std::env::var("DB_HOST")
-            );
-
-            // Was sieht dotenvy? (Ist wahrscheinlich Ok(...) wegen .env)
-            println!(
-                "Inside temp_env (unset): dotenvy::var(\"DB_HOST\") is {:?}",
-                dotenvy::var("DB_HOST")
-            );
-
-            // Jetzt der Aufruf, der panicen sollte
-            build_database_url();
-        });
+        temp_env::with_vars(
+            [
+                ("DB_USER", None::<&str>),
+                ("DB_NAME", None::<&str>),
+                ("DB_PASSWORD", None::<&str>),
+                ("DB_HOST", Some("localhost")),
+                ("DB_PORT", None::<&str>),
+            ],
+            || {
+                let expected_url = "postgresql://pgg:pgg@localhost:5432/pgg";
+                let actual_url = build_database_url();
+                assert_eq!(
+                    actual_url, expected_url,
+                    "Database URL should use default values for unset env vars."
+                );
+            },
+        );
     }
 
     #[test]
     fn build_database_url_with_all_vars() {
-        dotenvy::dotenv().ok();
         with_vars(
             [
                 ("DB_USER", Some("testuser")),
@@ -139,7 +139,8 @@ mod tests {
     #[test]
     #[should_panic(expected = "DB_HOST must be set in .env")]
     fn build_database_url_missing_host_panics() {
-        dotenvy::dotenv().ok();
-        build_database_url();
+        with_vars_unset(["DB_HOST"], || {
+            build_database_url();
+        });
     }
 }