Fix amount parsing for negative amounts <1

src/transaction.rs

@@ -6,18 +6,22 @@ pub struct Transaction {
     pub amount: i64,
 }
 
-fn parse_amount_str(amount: &str) -> Result<i64, Error> {
-    if amount.is_empty() {
+fn parse_amount_str(amount_str: &str) -> Result<i64, Error> {
+    if amount_str.is_empty() {
         return Err(Error::AmountEmpty);
     }
-    let (whole, frac) = amount.split_once('.').unwrap_or((amount, "00"));
+    let negative = amount_str.starts_with("-");
+    let amount_str = amount_str.trim_start_matches('-');
+
+    let (whole, frac) = amount_str.split_once('.').unwrap_or((amount_str, "00"));
     let whole = whole.parse::<i64>()?;
+    let frac = format!("{:0<2}", frac);
     let frac = frac.parse::<i64>()?;
 
     let mut amount: i64 = 0;
     amount += whole * 100 * 10;
-    amount += if whole < 0 { -frac } else { frac } * 10;
-    Ok(amount)
+    amount += frac * 10;
+    Ok(if negative { -amount } else { amount })
 }
 
 impl Transaction {