try a fp fuzz test (Uniswap#17)

* try a fp fuzz test * fix compiler error * tiny gas savings * remove fp test * remove fixedpoint test
rkirmann · Oct 22, 2020 · 43287bd · 43287bd
1 parent f0bd425
commit 43287bd
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Showing 4 changed files with 13 additions and 13 deletions.
diff --git a/.github/workflows/fuzz-testing.yml b/.github/workflows/fuzz-testing.yml
@@ -45,4 +45,4 @@ jobs:
 
       - name: Run echidna
         run: |
-          echidna-test . --contract EchidnaBabylonianTest
+          echidna-test . --contract BabylonianEchidnaTest
diff --git a/contracts/libraries/FixedPoint.sol b/contracts/libraries/FixedPoint.sol
@@ -19,8 +19,8 @@ library FixedPoint {
     }
 
     uint8 private constant RESOLUTION = 112;
-    uint256 private constant Q112 = uint256(1) << RESOLUTION;
-    uint256 private constant Q224 = Q112 << RESOLUTION;
+    uint256 private constant Q112 = 0x10000000000000000000000000000;
+    uint256 private constant Q224 = 0x100000000000000000000000000000000000000000000000000000000;
     uint256 private constant LOWER_MASK = 0xffffffffffffffffffffffffffff; // decimal of UQ*x112 (lower 112 bits)
 
     // encode a uint112 as a UQ112x112
@@ -55,7 +55,7 @@ library FixedPoint {
     // reverts on overflow
     function muli(uq112x112 memory self, int256 y) internal pure returns (int256) {
         uint256 z = FullMath.mulDiv(self._x, uint256(y < 0 ? -y : y), Q112);
-        require(z < 2**255, "FixedPoint: MULI_OVERFLOW");
+        require(z < 2**255, 'FixedPoint: MULI_OVERFLOW');
         return y < 0 ? -int256(z) : int256(z);
     }
 

diff --git a/contracts/test/EchidnaBabylonian.sol → contracts/test/BabylonianEchidnaTest.sol b/contracts/test/EchidnaBabylonian.sol → contracts/test/BabylonianEchidnaTest.sol
@@ -4,26 +4,26 @@ pragma solidity >=0.4.0;
 
 import '../libraries/Babylonian.sol';
 
-contract EchidnaBabylonianTest {
-    uint256 num;
+contract BabylonianEchidnaTest {
+    uint256 input;
     uint256 sqrt;
 
-    function storeSqrt(uint256 num_) external {
-        num = num_;
-        sqrt = Babylonian.sqrt(num_);
+    function storeSqrt(uint256 input_) external {
+        input = input_;
+        sqrt = Babylonian.sqrt(input_);
     }
 
     function echidna_sqrtAlwaysLessThanMaxUint128() external view returns (bool) {
         return sqrt < 2**128; // because (2**128)^2 > uint256(-1)
     }
 
     function echidna_sqrtSquaredAlwaysLteInput() external view returns (bool) {
-        return sqrt * sqrt <= num;
+        return sqrt * sqrt <= input;
     }
 
     function echidna_sqrtPlusOneSquaredAlwaysGtInput() external view returns (bool) {
         uint256 next = sqrt + 1;
         uint256 nextSquared = next * next;
-        return (nextSquared > num); /*|| ((nextSquared) / next != next)*/
+        return (nextSquared > input); /*|| ((nextSquared) / next != next)*/
     }
 }
diff --git a/test/FixedPoint.spec.ts b/test/FixedPoint.spec.ts
@@ -291,7 +291,7 @@ describe('FixedPoint', () => {
       // long division but makes fewer iterations
       expect(
         await fixedPoint.getGasCostOfDivuq([BigNumber.from(10).pow(10).mul(Q112)], [BigNumber.from(25).mul(Q112)])
-      ).to.eq(1443)
+      ).to.eq(1440)
     })
 
     it('gas cost of long division with all iterations', async () => {
@@ -301,7 +301,7 @@ describe('FixedPoint', () => {
           [BigNumber.from(10).pow(10).mul(Q112)],
           [BigNumber.from(3).mul(BigNumber.from(10).pow(10)).mul(Q112)]
         )
-      ).to.eq(1443)
+      ).to.eq(1440)
     })
   })