fix: displaying duplicate command suggestions

Fixes #955

yazi-core/src/which/commands/show.rs

@@ -1,6 +1,6 @@
-use std::str::FromStr;
+use std::{collections::HashMap, str::FromStr};
 
-use yazi_config::{keymap::{Control, Key}, KEYMAP};
+use yazi_config::{keymap::{Control, ControlCow, Key}, KEYMAP};
 use yazi_shared::{event::Cmd, render, Layer};
 
 use crate::which::{Which, WhichSorter};
@@ -45,16 +45,69 @@ impl Which {
 	pub fn show_with(&mut self, key: &Key, layer: Layer) {
 		self.layer = layer;
 		self.times = 1;
-		self.cands = KEYMAP
-			.get(layer)
-			.iter()
-			.filter(|c| c.on.len() > 1 && &c.on[0] == key)
-			.map(|c| c.into())
-			.collect();
+		self.cands = keymap_candidates(layer, key);
 
 		WhichSorter::default().sort(&mut self.cands);
 		self.visible = true;
 		self.silent = false;
 		render!();
 	}
 }
+
+fn keymap_candidates(layer: Layer, key: &Key) -> Vec<ControlCow> {
+	let mut results: HashMap<&Vec<Key>, ControlCow> = HashMap::new();
+
+	let matches = KEYMAP.get(layer).iter().filter(|c| c.on.len() > 1 && &c.on[0] == key);
+	for c in matches {
+		if !results.contains_key(&c.on) {
+			results.insert(&c.on, c.into());
+		}
+	}
+
+	results.into_values().collect()
+}
+
+#[cfg(test)]
+mod tests {
+	use std::collections::HashMap;
+
+	use super::*;
+
+	fn key(char: char) -> Key {
+		Key { code: crossterm::event::KeyCode::Char(char), alt: false, ctrl: false, shift: false }
+	}
+
+	#[test]
+	fn test_candidates_removes_duplicates() {
+		// When there are duplicate mappings in the [manager] section's prepend_keymap
+		// and keymap definitions, only the mapping in the prepend_keymap section will
+		// match. We should only display that one as a suggestion to the user.
+		let first = Control {
+			on:   vec![key('g'), key('c')],
+			run:  vec![Cmd { name: "noop".to_string(), args: HashMap::new() }],
+			desc: Some("do nothing".to_string()),
+		};
+		let second = Control {
+			on:   vec![key('g'), key('c')],
+			run:  vec![Cmd { name: "noop".to_string(), args: HashMap::new() }],
+			desc: Some("do nothing 2".to_string()),
+		};
+
+		KEYMAP.init(yazi_config::keymap::Keymap {
+			tasks:      vec![],
+			select:     vec![],
+			input:      vec![],
+			help:       vec![],
+			completion: vec![],
+			manager:    vec![first, second],
+		});
+
+		let cands = keymap_candidates(Layer::Manager, &key('g'));
+
+		// duplicates have been removed
+		assert_eq!(cands.len(), 1);
+
+		// the first one is kept
+		assert_eq!(cands[0].desc_or_run(), "do nothing");
+	}
+}