From a4091ade5cde7602acef0601cb7f69984fcad009 Mon Sep 17 00:00:00 2001
From: mo8it <mo8it@proton.me>
Date: Mon, 8 Jul 2024 14:40:35 +0200
Subject: [PATCH] iterators3: Add `IntegerOverflow` error variant

---
 exercises/18_iterators/iterators3.rs | 11 ++++++++++-
 solutions/18_iterators/iterators3.rs | 13 +++++++++++++
 2 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/exercises/18_iterators/iterators3.rs b/exercises/18_iterators/iterators3.rs
index 65a05734..6b1eca17 100644
--- a/exercises/18_iterators/iterators3.rs
+++ b/exercises/18_iterators/iterators3.rs
@@ -1,12 +1,16 @@
 #[derive(Debug, PartialEq, Eq)]
 enum DivisionError {
+    // Example: 42 / 0
     DivideByZero,
+    // Only case for `i64`: `i64::MIN / -1` because the result is `i64::MAX + 1`
+    IntegerOverflow,
+    // Example: 5 / 2 = 2.5
     NotDivisible,
 }
 
 // TODO: Calculate `a` divided by `b` if `a` is evenly divisible by `b`.
 // Otherwise, return a suitable error.
-fn divide(a: i32, b: i32) -> Result<i32, DivisionError> {
+fn divide(a: i64, b: i64) -> Result<i64, DivisionError> {
     todo!();
 }
 
@@ -42,6 +46,11 @@ mod tests {
         assert_eq!(divide(81, 0), Err(DivisionError::DivideByZero));
     }
 
+    #[test]
+    fn test_integer_overflow() {
+        assert_eq!(divide(i64::MIN, -1), Err(DivisionError::IntegerOverflow));
+    }
+
     #[test]
     fn test_not_divisible() {
         assert_eq!(divide(81, 6), Err(DivisionError::NotDivisible));
diff --git a/solutions/18_iterators/iterators3.rs b/solutions/18_iterators/iterators3.rs
index d66d1ef3..11aa1ec8 100644
--- a/solutions/18_iterators/iterators3.rs
+++ b/solutions/18_iterators/iterators3.rs
@@ -1,6 +1,10 @@
 #[derive(Debug, PartialEq, Eq)]
 enum DivisionError {
+    // Example: 42 / 0
     DivideByZero,
+    // Only case for `i64`: `i64::MIN / -1` because the result is `i64::MAX + 1`
+    IntegerOverflow,
+    // Example: 5 / 2 = 2.5
     NotDivisible,
 }
 
@@ -9,6 +13,10 @@ fn divide(a: i64, b: i64) -> Result<i64, DivisionError> {
         return Err(DivisionError::DivideByZero);
     }
 
+    if a == i64::MIN && b == -1 {
+        return Err(DivisionError::IntegerOverflow);
+    }
+
     if a % b != 0 {
         return Err(DivisionError::NotDivisible);
     }
@@ -51,6 +59,11 @@ mod tests {
         assert_eq!(divide(81, 0), Err(DivisionError::DivideByZero));
     }
 
+    #[test]
+    fn test_integer_overflow() {
+        assert_eq!(divide(i64::MIN, -1), Err(DivisionError::IntegerOverflow));
+    }
+
     #[test]
     fn test_not_divisible() {
         assert_eq!(divide(81, 6), Err(DivisionError::NotDivisible));