fix bug in function preciseDivCeil (#191)

Fix bug in function preciseDivCeil. Fix bug in function preciseDivCeilInt in file utils/common/mathUtils.ts

Co-authored-by: Dan Liu <[email protected]>

Author: gzliudan

contracts/lib/PreciseUnitMath.sol

@@ -147,9 +147,11 @@ library PreciseUnitMath {
 
         a = a.mul(PRECISE_UNIT_INT);
         int256 c = a.div(b);
-        if (c * b != a) {
-            c = c > 0 ? c + 1 : c - 1;
+
+        if (a % b != 0) {
+            (a ^ b > 0) ? ++c : --c;
         }
+
         return c;
     }
 

utils/common/mathUtils.ts

@@ -39,14 +39,15 @@ export const preciseDivCeil = (a: BigNumber, b: BigNumber): BigNumber => {
 };
 
 export const preciseDivCeilInt = (a: BigNumber, b: BigNumber): BigNumber => {
-  if (a.eq(0) || b.eq(0)) {
-    return ZERO;
+  const result = a.mul(PRECISE_UNIT).div(b);
+  if (result.mul(b).eq(a.mul(PRECISE_UNIT))) {
+    return result;
   }
 
-  if (a.gt(0) && b.gt(0) || a.lt(0) && b.lt(0)) {
-    return a.mul(PRECISE_UNIT).sub(1).div(b).add(1);
+  if ((a.gt(0) && b.gt(0)) || (a.lt(0) && b.lt(0))) {
+    return result.add(1);
   } else {
-    return a.mul(PRECISE_UNIT).add(1).div(b).sub(1);
+    return result.sub(1);
   }
 };