Apply clippy suggestions

- Use `BTreeMap::entry` API in `update_item`
- Replace `or_insert_with(Vec::new)` with `or_default`
- Iterate over map values instead of key-value pairs
- Use `std::io::Error::other` for custom errors
- Simplify filter logic with direct predicate
- Replace manual `Into` implementation with `From`
- Remove unnecessary explicit returns

5 files changed, 19 insertions, 35 deletions

diff --git a/src/bill.rs b/src/bill.rs
index 291b759..62a1d3b 100644
--- a/src/bill.rs
+++ b/src/bill.rs
@@ -62,8 +62,10 @@ impl Bills {
 
     /// Update the bill item with the specified ID
     pub fn update_item(&mut self, id: &Uuid, item: BillItem) -> bool {
-        if self.items.contains_key(&id.to_string()) {
-            self.items.insert(id.to_string(), item);
+        if let std::collections::btree_map::Entry::Occupied(mut e) =
+            self.items.entry(id.to_string())
+        {
+            e.insert(item);
             true
         } else {
             false
@@ -100,10 +102,7 @@ impl SplitResult {
             reason,
         };
 
-        self.items
-            .entry(payer)
-            .or_insert_with(Vec::new)
-            .push(result_item);
+        self.items.entry(payer).or_default().push(result_item);
     }
 
     /// Get all bill items for a specified payer (immutable reference)
diff --git a/src/calc.rs b/src/calc.rs
index fcd0f5b..d1209c3 100644
--- a/src/calc.rs
+++ b/src/calc.rs
@@ -27,7 +27,7 @@ pub fn calculate_from(item: Bills) -> Result<SplitResult, BillSplitError> {
 }
 
 fn precheck(item: &Bills) -> Result<(), BillSplitError> {
-    for (_, bill_item) in &item.items {
+    for bill_item in item.items.values() {
         // Check if the paid amount is negative
         if bill_item.paid < 0.0 {
             return Err(BillSplitError::NegativePaidAmount);
@@ -44,16 +44,14 @@ fn precheck(item: &Bills) -> Result<(), BillSplitError> {
     Ok(())
 }
 
-fn calculate_balances_and_transactions(
-    item: &Bills,
-) -> (
-    BTreeMap<(Who, Who), f64>,
-    BTreeMap<Who, Vec<SplitResultItem>>,
-) {
+type DirectTransactions = BTreeMap<(Who, Who), f64>;
+type ItemsByWho = BTreeMap<Who, Vec<SplitResultItem>>;
+
+fn calculate_balances_and_transactions(item: &Bills) -> (DirectTransactions, ItemsByWho) {
     let mut direct_transactions: BTreeMap<(Who, Who), f64> = BTreeMap::new();
     let mut items: BTreeMap<Who, Vec<SplitResultItem>> = BTreeMap::new();
 
-    for (_, bill_item) in &item.items {
+    for bill_item in item.items.values() {
         let who_paid = &bill_item.who_paid;
         let paid = bill_item.paid;
         let split_count = bill_item.split.len() as f64;
@@ -82,7 +80,7 @@ fn calculate_balances_and_transactions(
 
                 items
                     .entry(person.clone())
-                    .or_insert_with(Vec::new)
+                    .or_default()
                     .push(bill_result_item);
             }
         }
diff --git a/src/cli.rs b/src/cli.rs
index 44c1f8f..9c17ebb 100644
--- a/src/cli.rs
+++ b/src/cli.rs
@@ -122,7 +122,7 @@ fn name_suggest(typed: Vec<String>) -> Suggest {
             suggest.insert(SuggestItem::Simple(member));
         }
     }
-    return suggest;
+    suggest
 }
 
 #[completion(ListAllBillEntry)]
@@ -353,10 +353,7 @@ fn read_bills() -> Bills {
     let state_file = state_file_path();
     if state_file.exists() {
         match std::fs::read_to_string(&state_file) {
-            Ok(contents) => match serde_yaml::from_str(&contents) {
-                Ok(bills) => bills,
-                Err(_) => Bills::default(),
-            },
+            Ok(contents) => serde_yaml::from_str(&contents).unwrap_or_default(),
             Err(_) => Bills::default(),
         }
     } else {
diff --git a/src/edit.rs b/src/edit.rs
index f9c751c..d505fc8 100644
--- a/src/edit.rs
+++ b/src/edit.rs
@@ -17,10 +17,7 @@ pub fn input_with_editor_cutsom(
     let status = Command::new(editor).arg(cache_path).status()?;
 
     if !status.success() {
-        return Err(std::io::Error::new(
-            std::io::ErrorKind::Other,
-            "Editor exited with non-zero status",
-        ));
+        return Err(std::io::Error::other("Editor exited with non-zero status"));
     }
 
     // Read the modified content
@@ -29,14 +26,7 @@ pub fn input_with_editor_cutsom(
     // Remove comment lines and trim
     let processed_content: String = content
         .lines()
-        .filter_map(|line| {
-            let trimmed = line.trim();
-            if trimmed.starts_with(comment_prefix) {
-                None
-            } else {
-                Some(line)
-            }
-        })
+        .filter(|line| !line.trim().starts_with(comment_prefix))
         .collect::<Vec<&str>>()
         .join("\n");
 
diff --git a/src/who.rs b/src/who.rs
index 32f536b..8e16765 100644
--- a/src/who.rs
+++ b/src/who.rs
@@ -33,9 +33,9 @@ impl From<&str> for Who {
     }
 }
 
-impl Into<String> for Who {
-    fn into(self) -> String {
-        self.name
+impl From<Who> for String {
+    fn from(val: Who) -> Self {
+        val.name
     }
 }