From aee8580c084084b612b3435c3d5a768bf5f4c865 Mon Sep 17 00:00:00 2001
From: Wojciech <cichockiwojciech97@gmail.com>
Date: Wed, 11 Oct 2023 14:45:37 +0200
Subject: [PATCH] Add checked_div implementation

---
 decimal_core/src/checked_ops.rs | 28 ++++++++++++++++++++++++++++
 src/traits.rs                   |  2 +-
 2 files changed, 29 insertions(+), 1 deletion(-)

diff --git a/decimal_core/src/checked_ops.rs b/decimal_core/src/checked_ops.rs
index 7af8f02..b884e33 100644
--- a/decimal_core/src/checked_ops.rs
+++ b/decimal_core/src/checked_ops.rs
@@ -24,6 +24,17 @@ pub fn generate_checked_ops(characteristics: DecimalCharacteristics) -> proc_mac
                     .ok_or_else(|| "checked_sub: (self - rhs) subtraction underflow")?
                 ))
             }
+
+            fn checked_div(self, rhs: Self) -> std::result::Result<Self, String> {
+                Ok(Self::new(
+                        self.get()
+                        .checked_mul(Self::one())
+                        .ok_or_else(|| "checked_div: (self * Self::one()) multiplication overflow")?
+                        .checked_div(rhs.get())
+                        .ok_or_else(|| "checked_div: ((self * Self::one()) / rhs) division by zero")?
+                    )
+                )
+            }
         }
 
         #[cfg(test)]
@@ -54,6 +65,23 @@ pub fn generate_checked_ops(characteristics: DecimalCharacteristics) -> proc_mac
                 assert_eq!(a.checked_sub(b), Ok(#struct_name::new(24)));
             }
 
+            #[test]
+            fn test_checked_div() {
+                let a = #struct_name::new(2);
+                let b = #struct_name::new(#struct_name::one());
+
+                assert_eq!(a.checked_div(b), Ok(#struct_name::new(2)));
+            }
+
+            #[test]
+            fn test_0_checked_div() {
+                let a = #struct_name::new(47);
+                let b = #struct_name::new(0);
+                let result = a.checked_div(b);
+
+                assert!(result.is_err());
+            }
+
             #[test]
             fn test_underflow_checked_sub() {
                 let min = #struct_name::new(0);
diff --git a/src/traits.rs b/src/traits.rs
index 9cc8389..9795748 100644
--- a/src/traits.rs
+++ b/src/traits.rs
@@ -39,7 +39,6 @@ pub trait Factories<T>: Sized {
     fn from_scale_up(integer: T, scale: u8) -> Self;
 }
 
-
 pub trait BetweenDecimals<T>: Sized {
     fn from_decimal(other: T) -> Self;
     fn checked_from_decimal(other: T) -> std::result::Result<Self, String>;
@@ -69,4 +68,5 @@ pub trait ByNumber<B>: Sized {
 pub trait CheckedOps: Sized {
     fn checked_add(self, rhs: Self) -> std::result::Result<Self, String>;
     fn checked_sub(self, rhs: Self) -> std::result::Result<Self, String>;
+    fn checked_div(self, rhs: Self) -> std::result::Result<Self, String>;
 }