homework: options instead panics

smart-house/README.md

@@ -71,8 +71,8 @@
 ### Описание/Пошаговая инструкция выполнения домашнего задания:
 
 Добавить обработку ошибок:
-- [ ] Заменить паники на возврат Option в методах получения комнаты по ключу.
+- [x] Заменить паники на возврат Option в методах получения комнаты по ключу.
-- [ ] Заменить паники на возврат Option в методах получения устройства по ключу.
+- [x] Заменить паники на возврат Option в методах получения устройства по ключу.
 
 Доработать хранение объектов:
 - [ ] Заменить массивы устройств и комнат на ассоциативные коллекции из std. В качестве ключей использовать строки.

smart-house/src/house.rs

@@ -13,20 +13,16 @@ impl House {
         }
     }
 
-    fn check_bounds(&self, idx: usize) {
+    fn is_valid_idx(&self, idx: usize) -> bool {
-        if idx >= self.rooms.len() {
+        idx < self.rooms.len()
-            panic!("Index is out of bounds")
-        }
     }
 
-    pub fn get_room(&self, idx: usize) -> &Room {
+    pub fn get_room(&self, idx: usize) -> Option<&Room> {
-        self.check_bounds(idx);
+        if self.is_valid_idx(idx) { Some(&self.rooms[idx]) } else { None }
-        &self.rooms[idx]
     }
 
-    pub fn get_room_mut(&mut self, idx: usize) -> &mut Room {
+    pub fn get_room_mut(&mut self, idx: usize) -> Option<&mut Room> {
-        self.check_bounds(idx);
+        if self.is_valid_idx(idx) { Some(&mut self.rooms[idx]) } else { None }
-        &mut self.rooms[idx]
     }
 
     pub fn print_status(&self) {
@@ -70,22 +66,33 @@ mod tests {
         house.print_status();
         assert_eq!(house.address, "Best street, 777");
 
-        assert_eq!(format!("{}", house.get_room(0).get_device(0).display()), "DEV:Thermometer[ 20.0 ]");
+        assert_eq!(
-        assert_eq!(format!("{}", house.get_room(0).get_device(1).display()), "DEV:PowerSocket[ OFF : 0.0 ]");
+            format!("{}", house.get_room(0).unwrap().get_device(0).unwrap().display()),
-        assert_eq!(format!("{}", house.get_room(1).get_device(0).display()), "DEV:PowerSocket[ ON : 11.1 ]");
+            "DEV:Thermometer[ 20.0 ]"
+        );
+        assert_eq!(
+            format!("{}", house.get_room(0).unwrap().get_device(1).unwrap().display()),
+            "DEV:PowerSocket[ OFF : 0.0 ]"
+        );
+        assert_eq!(
+            format!("{}", house.get_room(1).unwrap().get_device(0).unwrap().display()),
+            "DEV:PowerSocket[ ON : 11.1 ]"
+        );
 
-        let Device::PowerSocket(powers_socket) = house.get_room_mut(0).get_device_mut(1) else {
+        let Device::PowerSocket(powers_socket) = house.get_room_mut(0).unwrap().get_device_mut(1).unwrap() else {
             unreachable!()
         };
         powers_socket.set_on(true);
 
-        assert_eq!(format!("{}", house.get_room(0).get_device(1).display()), "DEV:PowerSocket[ ON : 12.3 ]");
+        assert_eq!(
+            format!("{}", house.get_room(0).unwrap().get_device(1).unwrap().display()),
+            "DEV:PowerSocket[ ON : 12.3 ]"
+        );
     }
 
     #[test]
-    #[should_panic(expected = "Index is out of bounds")]
+    fn check_out_of_bounds() {
-    fn panic_test() {
         let house = create_test_house();
-        house.check_bounds(2);
+        assert!(house.get_room(2).is_none());
     }
 }

smart-house/src/main.rs

@@ -26,7 +26,7 @@ fn main() {
     house.print_status();
 
     print!("# Switching off a power socket in Hall... ");
-    let Device::PowerSocket(power_socket) = house.get_room_mut(0).get_device_mut(0) else {
+    let Device::PowerSocket(power_socket) = house.get_room_mut(0).unwrap().get_device_mut(0).unwrap() else {
         println!("FAILED!");
         return;
     };

smart-house/src/room.rs

@@ -13,20 +13,17 @@ impl Room {
         }
     }
 
-    fn check_bounds(&self, idx: usize) {
+    fn is_valid_idx(&self, idx: usize) -> bool {
-        if idx >= self.devices.len() {
+        idx < self.devices.len()
-            panic!("Index is out of bounds")
-        }
     }
 
-    pub fn get_device(&self, idx: usize) -> &Device {
+    pub fn get_device(&self, idx: usize) -> Option<&Device> {
-        self.check_bounds(idx);
+        if self.is_valid_idx(idx) { Some(&self.devices[idx]) } else { None }
-        &self.devices[idx]
     }
 
-    pub fn get_device_mut(&mut self, idx: usize) -> &mut Device {
+    pub fn get_device_mut(&mut self, idx: usize) -> Option<&mut Device> {
-        self.check_bounds(idx);
+        self.is_valid_idx(idx);
-        &mut self.devices[idx]
+        Some(&mut self.devices[idx])
     }
 
     pub fn print_status(&self) {
@@ -53,21 +50,20 @@ mod tests {
         assert_eq!(room.name, "test_room");
         room.print_status();
 
-        assert_eq!(format!("{}", room.get_device(0).display()), "DEV:PowerSocket[ OFF : 0.0 ]");
+        assert_eq!(format!("{}", room.get_device(0).unwrap().display()), "DEV:PowerSocket[ OFF : 0.0 ]");
-        assert_eq!(format!("{}", room.get_device(1).display()), "DEV:Thermometer[ 21.6 ]");
+        assert_eq!(format!("{}", room.get_device(1).unwrap().display()), "DEV:Thermometer[ 21.6 ]");
 
-        let Device::PowerSocket(power_socket) = room.get_device_mut(0) else {
+        let Device::PowerSocket(power_socket) = room.get_device_mut(0).unwrap() else {
             unreachable!()
         };
         power_socket.set_on(true);
 
-        assert_eq!(format!("{}", room.get_device(0).display()), "DEV:PowerSocket[ ON : 12.3 ]");
+        assert_eq!(format!("{}", room.get_device(0).unwrap().display()), "DEV:PowerSocket[ ON : 12.3 ]");
-        assert_eq!(format!("{}", room.get_device(1).display()), "DEV:Thermometer[ 21.6 ]");
+        assert_eq!(format!("{}", room.get_device(1).unwrap().display()), "DEV:Thermometer[ 21.6 ]");
     }
 
     #[test]
-    #[should_panic(expected = "Index is out of bounds")]
+    fn check_out_of_bounds() {
-    fn panic_test() {
         let room = Room::new(
             "test_room",
             Box::new([
@@ -75,6 +71,6 @@ mod tests {
                 Device::Thermometer(Thermometer::new(21.56)),
             ]),
         );
-        room.check_bounds(2);
+        assert!(room.get_device(2).is_none());
     }
 }