Insert key code/name mapping entries without accidental overwriting

Author: homeworkprod

src/buttons.rs

@@ -19,7 +19,7 @@ pub(crate) fn handle_button_presses(
     buttons_to_key_code_names: HashMap<Button, KeyName>,
     event_sender: EventSender,
 ) -> Result<()> {
-    let key_code_name_mapping = KeyCodeNameMapping::new();
+    let key_code_name_mapping = KeyCodeNameMapping::new()?;
 
     let key_codes_to_buttons =
         KeyCodeToButtonMapping::new(key_code_name_mapping, buttons_to_key_code_names)?;

src/keycodenames.rs

@@ -3,6 +3,7 @@
  * License: MIT
  */
 
+use anyhow::{Result, anyhow};
 use bimap::BiMap;
 use evdev::KeyCode;
 
@@ -13,75 +14,83 @@ pub(crate) struct KeyCodeNameMapping {
 }
 
 impl KeyCodeNameMapping {
-    pub(crate) fn new() -> Self {
+    pub(crate) fn new() -> Result<Self> {
         let mut names_to_codes: BiMap<KeyName, KeyCode> = BiMap::new();
 
-        let mut insert = |name: &str, code: KeyCode| {
-            names_to_codes.insert(name.to_owned(), code);
+        let mut insert = |name: &str, code: KeyCode| -> Result<()> {
+            names_to_codes
+                .insert_no_overwrite(name.to_owned(), code)
+                .map_err(|(name, code)| {
+                    anyhow!(
+                        "Inserting ({:?}, {:?}) without overwrite failed",
+                        name,
+                        code
+                    )
+                })
         };
 
         // See file `/usr/include/linux/input-event-codes.h` (or
         // https://github.com/torvalds/linux/blob/master/include/uapi/linux/input-event-codes.h
         // on the web) for details.
 
         // mouse
-        insert("left", KeyCode::BTN_LEFT);
-        insert("right", KeyCode::BTN_RIGHT);
-        insert("middle", KeyCode::BTN_MIDDLE);
-        insert("side", KeyCode::BTN_SIDE);
-        insert("extra", KeyCode::BTN_EXTRA);
-        insert("forward", KeyCode::BTN_FORWARD);
-        insert("back", KeyCode::BTN_BACK);
-        insert("task", KeyCode::BTN_TASK);
+        insert("left", KeyCode::BTN_LEFT)?;
+        insert("right", KeyCode::BTN_RIGHT)?;
+        insert("middle", KeyCode::BTN_MIDDLE)?;
+        insert("side", KeyCode::BTN_SIDE)?;
+        insert("extra", KeyCode::BTN_EXTRA)?;
+        insert("forward", KeyCode::BTN_FORWARD)?;
+        insert("back", KeyCode::BTN_BACK)?;
+        insert("task", KeyCode::BTN_TASK)?;
 
         // joystick
-        insert("trigger", KeyCode::BTN_TRIGGER);
-        insert("thumb", KeyCode::BTN_THUMB);
-        insert("thumb2", KeyCode::BTN_THUMB2);
-        insert("top", KeyCode::BTN_TOP);
-        insert("top2", KeyCode::BTN_TOP2);
-        insert("pinkie", KeyCode::BTN_PINKIE);
-        insert("base", KeyCode::BTN_BASE);
-        insert("base2", KeyCode::BTN_BASE2);
-        insert("base3", KeyCode::BTN_BASE3);
-        insert("base4", KeyCode::BTN_BASE4);
-        insert("base5", KeyCode::BTN_BASE5);
-        insert("base6", KeyCode::BTN_BASE6);
-        insert("dead", KeyCode::BTN_DEAD);
+        insert("trigger", KeyCode::BTN_TRIGGER)?;
+        insert("thumb", KeyCode::BTN_THUMB)?;
+        insert("thumb2", KeyCode::BTN_THUMB2)?;
+        insert("top", KeyCode::BTN_TOP)?;
+        insert("top2", KeyCode::BTN_TOP2)?;
+        insert("pinkie", KeyCode::BTN_PINKIE)?;
+        insert("base", KeyCode::BTN_BASE)?;
+        insert("base2", KeyCode::BTN_BASE2)?;
+        insert("base3", KeyCode::BTN_BASE3)?;
+        insert("base4", KeyCode::BTN_BASE4)?;
+        insert("base5", KeyCode::BTN_BASE5)?;
+        insert("base6", KeyCode::BTN_BASE6)?;
+        insert("dead", KeyCode::BTN_DEAD)?;
 
         // gamepad
-        insert("a", KeyCode::BTN_SOUTH);
-        insert("b", KeyCode::BTN_EAST);
-        insert("c", KeyCode::BTN_C);
-        insert("x", KeyCode::BTN_NORTH);
-        insert("y", KeyCode::BTN_WEST);
-        insert("z", KeyCode::BTN_Z);
-        insert("tl", KeyCode::BTN_TL);
-        insert("tr", KeyCode::BTN_TR);
-        insert("tl2", KeyCode::BTN_TL2);
-        insert("tr2", KeyCode::BTN_TR2);
-        insert("select", KeyCode::BTN_SELECT);
-        insert("start", KeyCode::BTN_START);
-        insert("mode", KeyCode::BTN_MODE);
-        insert("thumbl", KeyCode::BTN_THUMBL);
-        insert("thumbr", KeyCode::BTN_THUMBR);
+        insert("a", KeyCode::BTN_SOUTH)?;
+        insert("b", KeyCode::BTN_EAST)?;
+        insert("c", KeyCode::BTN_C)?;
+        insert("x", KeyCode::BTN_NORTH)?;
+        insert("y", KeyCode::BTN_WEST)?;
+        insert("z", KeyCode::BTN_Z)?;
+        insert("tl", KeyCode::BTN_TL)?;
+        insert("tr", KeyCode::BTN_TR)?;
+        insert("tl2", KeyCode::BTN_TL2)?;
+        insert("tr2", KeyCode::BTN_TR2)?;
+        insert("select", KeyCode::BTN_SELECT)?;
+        insert("start", KeyCode::BTN_START)?;
+        insert("mode", KeyCode::BTN_MODE)?;
+        insert("thumbl", KeyCode::BTN_THUMBL)?;
+        insert("thumbr", KeyCode::BTN_THUMBR)?;
 
         // directional pad
-        insert("dpad_up", KeyCode::BTN_DPAD_UP);
-        insert("dpad_down", KeyCode::BTN_DPAD_DOWN);
-        insert("dpad_left", KeyCode::BTN_DPAD_LEFT);
-        insert("dpad_right", KeyCode::BTN_DPAD_RIGHT);
+        insert("dpad_up", KeyCode::BTN_DPAD_UP)?;
+        insert("dpad_down", KeyCode::BTN_DPAD_DOWN)?;
+        insert("dpad_left", KeyCode::BTN_DPAD_LEFT)?;
+        insert("dpad_right", KeyCode::BTN_DPAD_RIGHT)?;
 
-        insert("trigger_happy1", KeyCode::BTN_TRIGGER_HAPPY1);
-        insert("trigger_happy2", KeyCode::BTN_TRIGGER_HAPPY2);
-        insert("trigger_happy3", KeyCode::BTN_TRIGGER_HAPPY3);
-        insert("trigger_happy4", KeyCode::BTN_TRIGGER_HAPPY4);
-        insert("trigger_happy5", KeyCode::BTN_TRIGGER_HAPPY5);
-        insert("trigger_happy6", KeyCode::BTN_TRIGGER_HAPPY6);
-        insert("trigger_happy7", KeyCode::BTN_TRIGGER_HAPPY7);
-        insert("trigger_happy8", KeyCode::BTN_TRIGGER_HAPPY8);
+        insert("trigger_happy1", KeyCode::BTN_TRIGGER_HAPPY1)?;
+        insert("trigger_happy2", KeyCode::BTN_TRIGGER_HAPPY2)?;
+        insert("trigger_happy3", KeyCode::BTN_TRIGGER_HAPPY3)?;
+        insert("trigger_happy4", KeyCode::BTN_TRIGGER_HAPPY4)?;
+        insert("trigger_happy5", KeyCode::BTN_TRIGGER_HAPPY5)?;
+        insert("trigger_happy6", KeyCode::BTN_TRIGGER_HAPPY6)?;
+        insert("trigger_happy7", KeyCode::BTN_TRIGGER_HAPPY7)?;
+        insert("trigger_happy8", KeyCode::BTN_TRIGGER_HAPPY8)?;
 
-        Self { names_to_codes }
+        Ok(Self { names_to_codes })
     }
 
     pub(crate) fn find_code_for_name(&self, name: KeyName) -> Option<&KeyCode> {