♻️ Better bound implementation (#220)

Co-authored-by: t11s <[email protected]>

Author: ZeroEkkusu

.gas-snapshot

@@ -18,7 +18,7 @@ Bytes32AddressLibTest:testFromLast20Bytes() (gas: 191)
 CREATE3Test:testDeployERC20() (gas: 852410)
 CREATE3Test:testFailDoubleDeployDifferentBytecode() (gas: 9079256848778914164)
 CREATE3Test:testFailDoubleDeploySameBytecode() (gas: 9079256848778906218)
-DSTestPlusTest:testBound() (gas: 16777)
+DSTestPlusTest:testBound() (gas: 14208)
 DSTestPlusTest:testBrutalizeMemory() (gas: 446)
 DSTestPlusTest:testFailBoundMinBiggerThanMax() (gas: 309)
 DSTestPlusTest:testRelApproxEqBothZeroesPasses() (gas: 413)

.prettierignore

@@ -0,0 +1 @@
+lib

package.json

@@ -15,6 +15,6 @@
     "prettier-plugin-solidity": "^1.0.0-beta.13"
   },
   "scripts": {
-    "lint": "prettier --write src/**/*.sol"
+    "lint": "prettier --write **.sol"
   }
 }

src/test/DSTestPlus.t.sol

@@ -5,12 +5,12 @@ import {DSTestPlus} from "./utils/DSTestPlus.sol";
 
 contract DSTestPlusTest is DSTestPlus {
     function testBound() public {
-        assertEq(bound(5, 0, 4), 0);
         assertEq(bound(0, 69, 69), 69);
         assertEq(bound(0, 68, 69), 68);
-        assertEq(bound(10, 150, 190), 174);
-        assertEq(bound(300, 2800, 3200), 3107);
-        assertEq(bound(9999, 1337, 6666), 4669);
+        assertEq(bound(5, 0, 4), 0);
+        assertEq(bound(9999, 1337, 6666), 6006);
+        assertEq(bound(0, type(uint256).max - 6, type(uint256).max), type(uint256).max - 6);
+        assertEq(bound(6, type(uint256).max - 6, type(uint256).max), type(uint256).max);
     }
 
     function testFailBoundMinBiggerThanMax() public {

src/test/utils/DSTestPlus.sol

@@ -141,16 +141,13 @@ contract DSTestPlus is DSTest {
 
         uint256 size = max - min;
 
-        if (max != type(uint256).max) size++; // Make the max inclusive.
-        if (size == 0) return min; // Using max would be equivalent as well.
-        // Ensure max is inclusive in cases where x != 0 and max is at uint max.
-        if (max == type(uint256).max && x != 0) x--; // Accounted for later.
-
-        if (x < min) x += size * (((min - x) / size) + 1);
-        result = min + ((x - min) % size);
-
-        // Account for decrementing x to make max inclusive.
-        if (max == type(uint256).max && x != 0) result++;
+        if (size == 0) result = min;
+        else if (size == type(uint256).max) result = x;
+        else {
+            ++size; // Make max inclusive.
+            uint256 mod = x % size;
+            result = min + mod;
+        }
 
         emit log_named_uint("Bound Result", result);
     }