From ca0122cfd13fc3556794d6b4b5abadb6893ac412 Mon Sep 17 00:00:00 2001
From: Diana Kocsis <diana.kocsis@uniswap.org>
Date: Wed, 24 Apr 2024 14:40:39 -0400
Subject: [PATCH 1/4] add UnsafeMath test file

---
 test/libraries/UnsafeMath.t.sol | 4 ++++
 1 file changed, 4 insertions(+)
 create mode 100644 test/libraries/UnsafeMath.t.sol

diff --git a/test/libraries/UnsafeMath.t.sol b/test/libraries/UnsafeMath.t.sol
new file mode 100644
index 000000000..5f3904561
--- /dev/null
+++ b/test/libraries/UnsafeMath.t.sol
@@ -0,0 +1,4 @@
+// SPDX-License-Identifier: UNLICENSED
+pragma solidity ^0.8.20;
+
+import {Test} from "forge-std/Test.sol";

From c24575be9fbefb9f37d28b12ba5159aa3e92d75d Mon Sep 17 00:00:00 2001
From: Diana Kocsis <diana.kocsis@uniswap.org>
Date: Wed, 24 Apr 2024 17:26:52 -0400
Subject: [PATCH 2/4] unsafe math test

---
 test/libraries/UnsafeMath.t.sol | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/test/libraries/UnsafeMath.t.sol b/test/libraries/UnsafeMath.t.sol
index 5f3904561..ced2d4333 100644
--- a/test/libraries/UnsafeMath.t.sol
+++ b/test/libraries/UnsafeMath.t.sol
@@ -2,3 +2,35 @@
 pragma solidity ^0.8.20;
 
 import {Test} from "forge-std/Test.sol";
+import {UnsafeMath} from "../../src/libraries/UnsafeMath.sol";
+
+contract UnsafeMathTest is Test {
+    using UnsafeMath for uint256;
+
+    uint256 constant Q128 = 2 ** 128;
+    uint256 constant MAX_UINT256 = type(uint256).max;
+
+    function test_divRoundingUp_zeroDoesNotRevert(uint256 x) public {
+        x.divRoundingUp(0);
+    }
+
+    function test_divRoundingUp_maxInput() public {
+        assertEq(MAX_UINT256.divRoundingUp(MAX_UINT256), 1);
+    }
+
+    function test_divRoundingUp_RoundsUp() public {
+        uint256 result = Q128 / 3 + 1;
+        assertEq(Q128.divRoundingUp(3), result);
+    }
+
+    function test_fuzz_divRoundingUp(uint256 x, uint256 y) public {
+        vm.assume(y != 0);
+        uint256 z = x.divRoundingUp(y);
+        uint256 diff = z - (x / y);
+        if (x % y == 0) {
+            assertEq(diff, 0);
+        } else {
+            assertEq(diff, 1);
+        }
+    }
+}
\ No newline at end of file

From 4c7dafc7ad1f63d4b9463e3a581f2130b2e4634e Mon Sep 17 00:00:00 2001
From: Diana Kocsis <diana.kocsis@uniswap.org>
Date: Wed, 24 Apr 2024 17:31:21 -0400
Subject: [PATCH 3/4] fix format, remove echidna test

---
 src/test/UnsafeMathEchidnaTest.sol | 17 -----------------
 test/libraries/UnsafeMath.t.sol    |  4 ++--
 2 files changed, 2 insertions(+), 19 deletions(-)
 delete mode 100644 src/test/UnsafeMathEchidnaTest.sol

diff --git a/src/test/UnsafeMathEchidnaTest.sol b/src/test/UnsafeMathEchidnaTest.sol
deleted file mode 100644
index 7d65ed0d9..000000000
--- a/src/test/UnsafeMathEchidnaTest.sol
+++ /dev/null
@@ -1,17 +0,0 @@
-// SPDX-License-Identifier: UNLICENSED
-pragma solidity ^0.8.20;
-
-import {UnsafeMath} from "../libraries/UnsafeMath.sol";
-
-contract UnsafeMathEchidnaTest {
-    function checkDivRoundingUp(uint256 x, uint256 d) external pure {
-        require(d > 0);
-        uint256 z = UnsafeMath.divRoundingUp(x, d);
-        uint256 diff = z - (x / d);
-        if (x % d == 0) {
-            assert(diff == 0);
-        } else {
-            assert(diff == 1);
-        }
-    }
-}
diff --git a/test/libraries/UnsafeMath.t.sol b/test/libraries/UnsafeMath.t.sol
index ced2d4333..963216615 100644
--- a/test/libraries/UnsafeMath.t.sol
+++ b/test/libraries/UnsafeMath.t.sol
@@ -10,7 +10,7 @@ contract UnsafeMathTest is Test {
     uint256 constant Q128 = 2 ** 128;
     uint256 constant MAX_UINT256 = type(uint256).max;
 
-    function test_divRoundingUp_zeroDoesNotRevert(uint256 x) public {
+    function test_divRoundingUp_zeroDoesNotRevert(uint256 x) public pure {
         x.divRoundingUp(0);
     }
 
@@ -33,4 +33,4 @@ contract UnsafeMathTest is Test {
             assertEq(diff, 1);
         }
     }
-}
\ No newline at end of file
+}

From bc5f8c0a95d512198091c83cff66b550d6e88cdf Mon Sep 17 00:00:00 2001
From: Diana Kocsis <diana.kocsis@uniswap.org>
Date: Thu, 25 Apr 2024 10:36:22 -0400
Subject: [PATCH 4/4] add invariant test

---
 test/libraries/UnsafeMath.t.sol | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/test/libraries/UnsafeMath.t.sol b/test/libraries/UnsafeMath.t.sol
index 963216615..501d0bbf1 100644
--- a/test/libraries/UnsafeMath.t.sol
+++ b/test/libraries/UnsafeMath.t.sol
@@ -24,6 +24,12 @@ contract UnsafeMathTest is Test {
     }
 
     function test_fuzz_divRoundingUp(uint256 x, uint256 y) public {
+        vm.assume(y != 0);
+        uint256 result = x.divRoundingUp(y);
+        assertTrue(result == x / y || result == x / y + 1);
+    }
+
+    function test_invariant_divRoundingUp(uint256 x, uint256 y) public {
         vm.assume(y != 0);
         uint256 z = x.divRoundingUp(y);
         uint256 diff = z - (x / y);