Use more error handling

Replace most of the panic calls by error handling with anyhow.

src/angel_shifts/bottle_angel.rs

@@ -5,6 +5,7 @@ use crate::resources;
 use crate::sprites;
 use crate::svg_loader;
 use crate::utils;
+use anyhow::Context;
 
 pub struct BottleAngelShift {
     hours: usize,
@@ -12,26 +13,29 @@ pub struct BottleAngelShift {
 }
 
 impl BottleAngelShift {
-    pub fn generate(rng: &mut impl rand::Rng) -> BottleAngelShift {
+    pub fn generate(rng: &mut impl rand::Rng) -> anyhow::Result<BottleAngelShift> {
         use rand::seq::SliceRandom;
 
         let compatible_levels = ["assembly-hall-1.svg", "ccl-ground-level.svg"];
 
-        BottleAngelShift {
+        Ok(BottleAngelShift {
             hours: rng.gen_range(1, 3),
-            level: compatible_levels.choose(rng).unwrap().to_string(),
-        }
+            level: compatible_levels
+                .choose(rng)
+                .context("Compatible level not found")?
+                .to_string(),
+        })
     }
 }
 
 impl super::AngelShiftImpl for BottleAngelShift {
-    fn metadata(&self) -> super::ShiftMetadata {
-        super::ShiftMetadata {
+    fn metadata(&self) -> anyhow::Result<super::ShiftMetadata> {
+        Ok(super::ShiftMetadata {
             title: "Bottle Angel".to_owned(),
             description: "Collect bottles from all bottle drop points in the designated area."
                 .to_owned(),
             hours: self.hours,
-        }
+        })
     }
 
     fn level_name(&self) -> &str {
@@ -44,17 +48,16 @@ impl super::AngelShiftImpl for BottleAngelShift {
         resources: &mut legion::Resources,
         schedule_builder: &mut legion::systems::Builder,
         level: &svg_loader::SvgLevel,
-    ) {
+    ) -> anyhow::Result<()> {
         // Display objective
-        let objective = utils::get_element_by_id::<web_sys::Element>("ingame-objective").unwrap();
+        let objective = utils::get_element_by_id::<web_sys::Element>("ingame-objective")?;
         objective.set_inner_html(
             r#"
             <text x="30" y="0" class="stats-label">Collect drop points:</text>
             <text id="ingame-bottle-angel-stats" x="430" y="0" class="stats-number">0/4</text>
         "#,
         );
-        let stats =
-            utils::get_element_by_id::<web_sys::Element>("ingame-bottle-angel-stats").unwrap();
+        let stats = utils::get_element_by_id::<web_sys::Element>("ingame-bottle-angel-stats")?;
 
         entities::create_drop_points(world, level);
         resources.insert(BottleAngelState::new(4, stats));
@@ -62,6 +65,7 @@ impl super::AngelShiftImpl for BottleAngelShift {
         schedule_builder
             .add_thread_local(collect_bottledrops_system())
             .add_thread_local(update_bottle_shift_system(self.hours));
+        Ok(())
     }
 }
 
@@ -98,24 +102,29 @@ pub fn collect_bottledrops(
     #[resource] player: &resources::Player,
     #[resource] collision_world: &colliders::CollisionWorld,
     #[resource] bottle_angel_state: &mut BottleAngelState,
-) {
+) -> anyhow::Result<()> {
     use legion::IntoQuery;
 
     let collider = <&colliders::Collider>::query()
         .get(world, player.0)
-        .unwrap();
+        .context("Couldn't find player")?;
 
     let mut bottledrops = <(&components::Matebottledrop, &mut components::Sprite)>::query();
     for pair in collision_world
         .world
-        .proximities_with(collider.handle.unwrap(), false)
-        .unwrap()
+        .proximities_with(collider.handle.context("No collider handler")?, false)
+        .context("Proximities not found")?
     {
         if pair.3 != ncollide2d::query::Proximity::Intersecting {
             continue;
         }
 
-        let entity = *collision_world.world.objects.get(pair.1).unwrap().data();
+        let entity = *collision_world
+            .world
+            .objects
+            .get(pair.1)
+            .context("Couldn't find counterpart")?
+            .data();
         if let Ok((_, sprite)) = bottledrops.get_mut(world, entity) {
             *sprite = components::Sprite::new(sprites::Sprite::BottleDropPointEmpty);
             cmd.remove_component::<components::Matebottledrop>(entity);
@@ -123,6 +132,7 @@ pub fn collect_bottledrops(
             bottle_angel_state.update_stats();
         }
     }
+    Ok(())
 }
 
 #[legion::system]
@@ -133,15 +143,16 @@ pub fn update_bottle_shift(
     #[resource] player: &mut resources::Player,
     #[resource] bottle_angel_state: &mut BottleAngelState,
     #[resource] game_manager: &mut resources::GameManager,
-) {
+) -> anyhow::Result<()> {
     use legion::IntoQuery;
 
     if bottle_angel_state.collected_drops >= bottle_angel_state.drops_in_map {
         let player = <&mut components::Player>::query()
             .get_mut(world, player.0)
-            .unwrap();
+            .context("Player not found")?;
         player.collected_hours += *hours_to_award as u32;
         *hours_to_award = 0;
         game_manager.request_return_to_heaven();
     }
+    Ok(())
 }

src/angel_shifts/definitions.rs

@@ -4,7 +4,7 @@ pub trait AngelShiftImpl {
     /// Return metadata about this shift.
     ///
     /// Used in heaven to display what task is up next.
-    fn metadata(&self) -> ShiftMetadata;
+    fn metadata(&self) -> anyhow::Result<ShiftMetadata>;
 
     /// Return name of the selected level for this shift.
     fn level_name(&self) -> &str;
@@ -20,7 +20,7 @@ pub trait AngelShiftImpl {
         resources: &mut legion::Resources,
         schedule_builder: &mut legion::systems::Builder,
         level: &svg_loader::SvgLevel,
-    );
+    ) -> anyhow::Result<()>;
 }
 
 pub struct ShiftMetadata {
@@ -35,7 +35,7 @@ pub struct ShiftMetadata {
 pub struct AngelShift(pub Box<dyn AngelShiftImpl>);
 
 impl AngelShift {
-    pub fn metadata(&self) -> ShiftMetadata {
+    pub fn metadata(&self) -> anyhow::Result<ShiftMetadata> {
         self.0.metadata()
     }
 
@@ -49,8 +49,8 @@ impl AngelShift {
         resources: &mut legion::Resources,
         schedule_builder: &mut legion::systems::Builder,
         level: &svg_loader::SvgLevel,
-    ) {
+    ) -> anyhow::Result<()> {
         self.0
-            .init_gameworld(world, resources, schedule_builder, level);
+            .init_gameworld(world, resources, schedule_builder, level)
     }
 }

src/angel_shifts/mod.rs

@@ -6,10 +6,10 @@ pub use definitions::AngelShift;
 pub use definitions::AngelShiftImpl;
 pub use definitions::ShiftMetadata;
 
-pub fn generate_random_shift(rng: &mut impl rand::Rng) -> AngelShift {
-    AngelShift(match rng.gen_range(0usize, 2) {
-        0 => Box::new(bottle_angel::BottleAngelShift::generate(rng)),
-        1 => Box::new(network_switch::NetworkSwitchShift::generate(rng)),
+pub fn generate_random_shift(rng: &mut impl rand::Rng) -> anyhow::Result<AngelShift> {
+    Ok(AngelShift(match rng.gen_range(0usize, 2) {
+        0 => Box::new(bottle_angel::BottleAngelShift::generate(rng)?),
+        1 => Box::new(network_switch::NetworkSwitchShift::generate(rng)?),
         _ => unreachable!(),
-    })
+    }))
 }

src/angel_shifts/network_switch.rs

@@ -5,6 +5,7 @@ use crate::resources;
 use crate::sprites;
 use crate::svg_loader;
 use crate::utils;
+use anyhow::Context;
 
 pub struct NetworkSwitchShift {
     hours: usize,
@@ -12,15 +13,18 @@ pub struct NetworkSwitchShift {
 }
 
 impl NetworkSwitchShift {
-    pub fn generate(rng: &mut impl rand::Rng) -> NetworkSwitchShift {
+    pub fn generate(rng: &mut impl rand::Rng) -> anyhow::Result<NetworkSwitchShift> {
         use rand::seq::SliceRandom;
 
         let compatible_levels = ["assembly-hall-1.svg"];
 
-        NetworkSwitchShift {
+        Ok(NetworkSwitchShift {
             hours: rng.gen_range(1, 3),
-            level: compatible_levels.choose(rng).unwrap().to_string(),
-        }
+            level: compatible_levels
+                .choose(rng)
+                .context("Compatible level not found")?
+                .to_string(),
+        })
     }
 }
 
@@ -48,12 +52,12 @@ impl NetworkSwitchAngelState {
 }
 
 impl super::AngelShiftImpl for NetworkSwitchShift {
-    fn metadata(&self) -> super::ShiftMetadata {
-        super::ShiftMetadata {
+    fn metadata(&self) -> anyhow::Result<super::ShiftMetadata> {
+        Ok(super::ShiftMetadata {
             title: "Fix the internet".to_owned(),
             description: "Check what's wrong with the network switches.".to_owned(),
             hours: self.hours,
-        }
+        })
     }
 
     fn level_name(&self) -> &str {
@@ -66,22 +70,23 @@ impl super::AngelShiftImpl for NetworkSwitchShift {
         resources: &mut legion::Resources,
         schedule_builder: &mut legion::systems::Builder,
         level: &svg_loader::SvgLevel,
-    ) {
+    ) -> anyhow::Result<()> {
         // Display objective
-        let objective = utils::get_element_by_id::<web_sys::Element>("ingame-objective").unwrap();
+        let objective = utils::get_element_by_id::<web_sys::Element>("ingame-objective")?;
         objective.set_inner_html(
             r#"
             <text x="30" y="0" class="stats-label">Switches online:</text>
             <text id="ingame-network-stats" x="430" y="0" class="stats-number">0/4</text>
         "#,
         );
-        let stats = utils::get_element_by_id::<web_sys::Element>("ingame-network-stats").unwrap();
+        let stats = utils::get_element_by_id::<web_sys::Element>("ingame-network-stats")?;
         entities::create_network_switches(world, level);
         resources.insert(NetworkSwitchAngelState::new(4, stats));
 
         schedule_builder
             .add_thread_local(reconnect_switches_system())
             .add_thread_local(update_network_switch_shift_system(self.hours));
+        Ok(())
     }
 }
 
@@ -95,24 +100,32 @@ pub fn reconnect_switches(
     #[resource] player: &resources::Player,
     #[resource] collision_world: &colliders::CollisionWorld,
     #[resource] angel_state: &mut NetworkSwitchAngelState,
-) {
+) -> anyhow::Result<()> {
     use legion::IntoQuery;
 
     let collider = <&colliders::Collider>::query()
         .get(world, player.0)
-        .unwrap();
+        .context("Player not found")?;
 
     let mut switches = <(&components::NetworkSwitch, &mut components::Sprite)>::query();
     for pair in collision_world
         .world
-        .proximities_with(collider.handle.unwrap(), false)
-        .unwrap()
+        .proximities_with(
+            collider.handle.context("Collider handler not found")?,
+            false,
+        )
+        .context("Proximities not found")?
     {
         if pair.3 != ncollide2d::query::Proximity::Intersecting {
             continue;
         }
 
-        let entity = *collision_world.world.objects.get(pair.1).unwrap().data();
+        let entity = *collision_world
+            .world
+            .objects
+            .get(pair.1)
+            .context("Couldn't find counterpart")?
+            .data();
         if let Ok((_, sprite)) = switches.get_mut(world, entity) {
             *sprite = components::Sprite::new(sprites::Sprite::NetworkSwitchConnected);
             cmd.remove_component::<components::NetworkSwitch>(entity);
@@ -120,6 +133,7 @@ pub fn reconnect_switches(
             angel_state.update_stats();
         }
     }
+    Ok(())
 }
 
 #[legion::system]
@@ -130,15 +144,16 @@ pub fn update_network_switch_shift(
     #[resource] player: &mut resources::Player,
     #[resource] angel_state: &mut NetworkSwitchAngelState,
     #[resource] game_manager: &mut resources::GameManager,
-) {
+) -> anyhow::Result<()> {
     use legion::IntoQuery;
 
     if angel_state.reconnected_switches >= angel_state.switches_in_map {
         let player = <&mut components::Player>::query()
             .get_mut(world, player.0)
-            .unwrap();
+            .context("Player not found")?;
         player.collected_hours += *hours_to_award as u32;
         *hours_to_award = 0;
         game_manager.request_return_to_heaven();
     }
+    Ok(())
 }

src/cheats.rs

@@ -59,7 +59,7 @@ pub fn cheat_set_sanity(val: f32) -> Result<(), wasm_bindgen::JsValue> {
     match || -> anyhow::Result<()> {
         // this is nice
         let state = get_cheat_state()?;
-        state.do_cheat(CheatCommand::SetSanity(val));
+        state.do_cheat(CheatCommand::SetSanity(val))?;
         Ok(())
     }() {
         // this is not nice
@@ -72,7 +72,7 @@ pub fn cheat_set_sanity(val: f32) -> Result<(), wasm_bindgen::JsValue> {
 pub fn cheat_set_shifts(val: u32) -> Result<(), wasm_bindgen::JsValue> {
     match || -> anyhow::Result<()> {
         let state = get_cheat_state()?;
-        state.do_cheat(CheatCommand::SetShifts(val));
+        state.do_cheat(CheatCommand::SetShifts(val))?;
         Ok(())
     }() {
         // this is not nice
@@ -84,7 +84,7 @@ pub fn cheat_set_shifts(val: u32) -> Result<(), wasm_bindgen::JsValue> {
 pub fn cheat_get_player() -> Result<(), wasm_bindgen::JsValue> {
     match || -> anyhow::Result<()> {
         let state = get_cheat_state()?;
-        state.do_cheat(CheatCommand::GetPlayer());
+        state.do_cheat(CheatCommand::GetPlayer())?;
         Ok(())
     }() {
         // this is not nice

src/components/edge.rs

@@ -20,12 +20,12 @@ impl Edge {
 pub fn draw_edges(
     world: &legion::world::SubWorld,
     #[resource] rendering: &mut resources::Rendering,
-) {
+) -> anyhow::Result<()> {
     // TODO: Replace by proper API
     for edge in <&Edge>::query().iter(world) {
         let mut positions = <&components::Position>::query();
-        let pos1 = positions.get(world, edge.node1).unwrap();
-        let pos2 = positions.get(world, edge.node2).unwrap();
+        let pos1 = positions.get(world, edge.node1)?;
+        let pos2 = positions.get(world, edge.node2)?;
 
         rendering.begin_path();
         rendering.set_line_width(7.0);
@@ -34,4 +34,6 @@ pub fn draw_edges(
         rendering.line_to(pos2.0.x as f64, pos2.0.y as f64);
         rendering.stroke();
     }
+
+    Ok(())
 }

src/error.rs

+use anyhow::Result;
+use wasm_bindgen::JsValue;
+use web_sys;
+
+pub trait AnyhowWebExt<T> {
+    fn to_anyhow(self) -> anyhow::Result<T>;
+}
+
+impl<T> AnyhowWebExt<T> for Result<T, JsValue> {
+    fn to_anyhow(self) -> anyhow::Result<T> {
+        self.map_err(|js_value| {
+            let error_message = match js_value.as_string() {
+                Some(string) => string,
+                None => "Unknown error".to_string(),
+            };
+            anyhow::anyhow!("{}", error_message)
+        })
+    }
+}
+
+impl<T> AnyhowWebExt<T> for Result<T, web_sys::Element> {
+    fn to_anyhow(self) -> anyhow::Result<T> {
+        self.map_err(|js_value| {
+            let error_message = match js_value.as_string() {
+                Some(string) => string,
+                None => "Unknown error".to_string(),
+            };
+            anyhow::anyhow!("{}", error_message)
+        })
+    }
+}

src/gamestate.rs

@@ -4,6 +4,10 @@ use std::rc::Rc;
 use crate::utils;
 use wasm_bindgen::closure;
 
+use crate::error::AnyhowWebExt;
+
+use anyhow::Context;
+
 pub enum Transition {
     /// Schedule a call of [`State::update`] with `requestAnimationFrame`.
     Loop,
@@ -47,15 +51,17 @@ impl Transition {
 }
 
 pub trait State {
-    fn init(&mut self, init: StateInitializer) -> Transition;
-    fn deinit(&mut self) {}
+    fn init(&mut self, init: StateInitializer) -> anyhow::Result<Transition>;
+    fn deinit(&mut self) -> anyhow::Result<()> {
+        Ok(())
+    }
 
-    fn update(&mut self, _timestamp: f64) -> Transition {
-        Transition::Keep
+    fn update(&mut self, _timestamp: f64) -> anyhow::Result<Transition> {
+        Ok(Transition::Keep)
     }
     #[allow(unused_variables)]
-    fn event(&mut self, event: Event) -> Transition {
-        Transition::Keep
+    fn event(&mut self, event: Event) -> anyhow::Result<Transition> {
+        Ok(Transition::Keep)
     }
 }
 
@@ -111,7 +117,10 @@ impl EventHandlers {
         self.mouse_handlers.insert(id.to_owned(), f);
     }
 
-    pub fn register_keyevents<F: FnMut(bool, &web_sys::KeyboardEvent) + 'static>(&mut self, f: F) {
+    pub fn register_keyevents<F: FnMut(bool, &web_sys::KeyboardEvent) + 'static>(
+        &mut self,
+        f: F,
+    ) -> anyhow::Result<()> {
         use wasm_bindgen::JsCast;
 
         let f = Rc::new(RefCell::new(f));
@@ -136,16 +145,21 @@ impl EventHandlers {
             f2.borrow_mut()(false, event)
         }) as Box<dyn FnMut(wasm_bindgen::JsValue)>);
 
-        let body = utils::document().body().unwrap();
+        let body = utils::document()
+            .body()
+            .context("document.body is undefined")?;
         body.set_onkeydown(Some(fdown.as_ref().unchecked_ref()));
         body.set_onkeyup(Some(fup.as_ref().unchecked_ref()));
 
         self.key_handlers = Some((fdown, fup));
+        Ok(())
     }
 
-    pub fn deregister_all(&mut self) {
+    pub fn deregister_all(&mut self) -> anyhow::Result<()> {
         if self.key_handlers.is_some() {
-            let body = utils::document().body().unwrap();
+            let body = utils::document()
+                .body()
+                .context("document.body is undefined")?;
             body.set_onkeydown(None);
             body.set_onkeyup(None);
         }
@@ -156,9 +170,10 @@ impl EventHandlers {
             } else if let Ok(el) = utils::get_element_by_id::<web_sys::HtmlElement>(id) {
                 el.set_onclick(None);
             } else {
-                panic!("Cannot find appropriate element {:?}", id);
+                return Err(anyhow::anyhow!("Cannot find appropriate element {:?}", id));
             }
         }
+        Ok(())
     }
 }
 
@@ -170,16 +185,16 @@ impl StateMachineHandle {
         StateMachineHandle(state_machine.clone())
     }
 
-    pub fn do_transition(&self, t: Transition) {
+    pub fn do_transition(&self, t: Transition) -> anyhow::Result<()> {
         StateMachine::do_transition(&self.0, t)
     }
 
-    pub fn do_event(&self, event: Event) {
-        let t = StateMachine::active(&self.0).event(event);
+    pub fn do_event(&self, event: Event) -> anyhow::Result<()> {
+        let t = StateMachine::active(&self.0).event(event)?;
         self.do_transition(t)
     }
 
-    pub fn do_cheat(&self, cheat: crate::cheats::CheatCommand) {
+    pub fn do_cheat(&self, cheat: crate::cheats::CheatCommand) -> anyhow::Result<()>{
         self.do_event(Event::Cheat(cheat))
     }
 
@@ -204,19 +219,22 @@ impl<'a> StateInitializer<'a> {
         }
     }
 
-    pub fn register_onclick(&mut self, id: &str) {
+    pub fn register_onclick(&mut self, id: &str) -> anyhow::Result<()> {
         let handle = self.handle.clone();
         let id2 = id.to_owned();
-        let canvas = utils::get_element_by_id::<web_sys::HtmlCanvasElement>("game-canvas").unwrap();
+        let canvas = utils::get_element_by_id::<web_sys::HtmlCanvasElement>("game-canvas")?;
         self.event_handlers.register_onclick(id, move |event| {
             let click = nalgebra::Point2::new(event.client_x() as f64, event.client_y() as f64);
             let canvas_click = utils::screen_to_contain_canvas(&canvas, click);
             let canvas_click = nalgebra::Point2::new(canvas_click.x as f32, canvas_click.y as f32);
-            handle.do_event(Event::MouseClick {
-                target: &id2,
-                coords: canvas_click,
-            });
+            handle
+                .do_event(Event::MouseClick {
+                    target: &id2,
+                    coords: canvas_click,
+                })
+                .unwrap(); // ignore-unwrap - unwrap inside a closure.
         });
+        Ok(())
     }
 
     pub fn register_keyevents(&mut self) {
@@ -224,11 +242,12 @@ impl<'a> StateInitializer<'a> {
         self.event_handlers
             .register_keyevents(move |keydown, event| {
                 if keydown {
-                    handle.do_event(Event::KeyDown(&event.key()));
+                    handle.do_event(Event::KeyDown(&event.key())).unwrap(); // ignore-unwrap - unwrap inside a closure
                 } else {
-                    handle.do_event(Event::KeyUp(&event.key()));
+                    handle.do_event(Event::KeyUp(&event.key())).unwrap(); // ignore-unwrap - unwrap inside a closure
                 }
-            });
+            })
+            .unwrap();
     }
 
     pub fn get_handle(&self) -> StateMachineHandle {
@@ -258,21 +277,22 @@ impl StateStorage {
 
     // ----------
 
-    pub fn init(&mut self, sm: &Rc<RefCell<StateMachine>>) -> Transition {
+    pub fn init(&mut self, sm: &Rc<RefCell<StateMachine>>) -> anyhow::Result<Transition> {
         self.state
             .init(StateInitializer::new(sm, &mut self.event_handlers))
     }
 
-    pub fn deinit(&mut self) {
-        self.state.deinit();
-        self.event_handlers.deregister_all();
+    pub fn deinit(&mut self) -> anyhow::Result<()> {
+        self.state.deinit()?;
+        self.event_handlers.deregister_all()?;
+        Ok(())
     }
 
-    pub fn update(&mut self, timestamp: f64) -> Transition {
+    pub fn update(&mut self, timestamp: f64) -> anyhow::Result<Transition> {
         self.state.update(timestamp)
     }
 
-    fn event(&mut self, event: Event) -> Transition {
+    fn event(&mut self, event: Event) -> anyhow::Result<Transition> {
         self.state.event(event)
     }
 }
@@ -284,7 +304,7 @@ pub struct StateMachine {
 }
 
 impl StateMachine {
-    pub fn launch<S: State + 'static>(initial: S) {
+    pub fn launch<S: State + 'static>(initial: S) -> anyhow::Result<()> {
         let this = Rc::new(RefCell::new(StateMachine {
             states: vec![StateStorage::new(initial)],
             loop_handler: None,
@@ -315,28 +335,31 @@ impl StateMachine {
                         return;
                     }
 
-                    active.update(timestamp)
+                    active.update(timestamp).unwrap() // ignore-unwrap - unwrap inside a closure
                 };
 
-                StateMachine::do_transition(&this, t);
+                StateMachine::do_transition(&this, t).unwrap();
             }) as Box<dyn FnMut(f64)>)
         };
         this.borrow_mut().loop_handler = Some(loop_handler);
 
-        let t = StateMachine::active(&this).init(&this);
-        StateMachine::do_transition(&this, t);
+