Fix formatting in CHANGELOG; add more cases to saturating_ tests to increase coverage

Author: ueco-jb

CHANGELOG.md

@@ -16,7 +16,8 @@ and this project adheres to
 - cosmwasm-std: Implement `checked_add`/`_sub`/`_div`/`_rem` for
   `Decimal`/`Decimal256`.
 - cosmwasm-std: Implement `pow`/`saturating_pow` for `Decimal`/`Decimal256`.
-- cosmwasm-std: Implement `saturating_add`/`sub`/`mul` for `Decimal`/`Decimal256`.
+- cosmwasm-std: Implement `saturating_add`/`sub`/`mul` for
+  `Decimal`/`Decimal256`.
 
 [#1334]: https://github.com/CosmWasm/cosmwasm/pull/1334
 

packages/std/src/math/decimal.rs

@@ -1886,18 +1886,34 @@ mod tests {
 
     #[test]
     fn decimal_saturating_works() {
+        assert_eq!(
+            Decimal::percent(200).saturating_add(Decimal::percent(200)),
+            Decimal::percent(400)
+        );
         assert_eq!(
             Decimal::MAX.saturating_add(Decimal::percent(200)),
             Decimal::MAX
         );
+        assert_eq!(
+            Decimal::percent(200).saturating_sub(Decimal::percent(100)),
+            Decimal::percent(100)
+        );
         assert_eq!(
             Decimal::zero().saturating_sub(Decimal::percent(200)),
             Decimal::zero()
         );
+        assert_eq!(
+            Decimal::percent(200).saturating_mul(Decimal::percent(50)),
+            Decimal::percent(100)
+        );
         assert_eq!(
             Decimal::MAX.saturating_mul(Decimal::percent(200)),
             Decimal::MAX
         );
+        assert_eq!(
+            Decimal::percent(400).saturating_pow(2u32),
+            Decimal::percent(1600)
+        );
         assert_eq!(Decimal::MAX.saturating_pow(2u32), Decimal::MAX);
     }
 }

packages/std/src/math/decimal256.rs

@@ -2036,18 +2036,34 @@ mod tests {
 
     #[test]
     fn decimal256_saturating_works() {
+        assert_eq!(
+            Decimal256::percent(200).saturating_add(Decimal256::percent(200)),
+            Decimal256::percent(400)
+        );
         assert_eq!(
             Decimal256::MAX.saturating_add(Decimal256::percent(200)),
             Decimal256::MAX
         );
+        assert_eq!(
+            Decimal256::percent(200).saturating_sub(Decimal256::percent(100)),
+            Decimal256::percent(100)
+        );
         assert_eq!(
             Decimal256::zero().saturating_sub(Decimal256::percent(200)),
             Decimal256::zero()
         );
+        assert_eq!(
+            Decimal256::percent(200).saturating_mul(Decimal256::percent(50)),
+            Decimal256::percent(100)
+        );
         assert_eq!(
             Decimal256::MAX.saturating_mul(Decimal256::percent(200)),
             Decimal256::MAX
         );
+        assert_eq!(
+            Decimal256::percent(400).saturating_pow(2u32),
+            Decimal256::percent(1600)
+        );
         assert_eq!(Decimal256::MAX.saturating_pow(2u32), Decimal256::MAX);
     }
 }