feat: Add wadraymath.ts to support wad and ray math on ethers bignu…

…mber

test-suites/helpers/utils/wadraymath.ts

@@ -0,0 +1,73 @@
+import { BigNumber } from '@ethersproject/bignumber';
+
+import {
+  RAY,
+  WAD,
+  HALF_RAY,
+  HALF_WAD,
+  WAD_RAY_RATIO,
+  HALF_PERCENTAGE,
+  PERCENTAGE_FACTOR,
+} from '../../../helpers/constants';
+
+declare module '@ethersproject/bignumber' {
+  interface BigNumber {
+    ray: () => BigNumber;
+    wad: () => BigNumber;
+    halfRay: () => BigNumber;
+    halfWad: () => BigNumber;
+    halfPercentage: () => BigNumber;
+    percentageFactor: () => BigNumber;
+    wadMul: (a: BigNumber) => BigNumber;
+    wadDiv: (a: BigNumber) => BigNumber;
+    rayMul: (a: BigNumber) => BigNumber;
+    rayDiv: (a: BigNumber) => BigNumber;
+    percentMul: (a: BigNumber) => BigNumber;
+    percentDiv: (a: BigNumber) => BigNumber;
+    rayToWad: () => BigNumber;
+    wadToRay: () => BigNumber;
+  }
+}
+
+BigNumber.prototype.ray = (): BigNumber => BigNumber.from(RAY);
+BigNumber.prototype.wad = (): BigNumber => BigNumber.from(WAD);
+BigNumber.prototype.halfRay = (): BigNumber => BigNumber.from(HALF_RAY);
+BigNumber.prototype.halfWad = (): BigNumber => BigNumber.from(HALF_WAD);
+BigNumber.prototype.halfPercentage = (): BigNumber => BigNumber.from(HALF_PERCENTAGE);
+BigNumber.prototype.percentageFactor = (): BigNumber => BigNumber.from(PERCENTAGE_FACTOR);
+
+BigNumber.prototype.wadMul = function (b: BigNumber): BigNumber {
+  return this.halfWad().add(this.mul(b)).div(this.wad());
+};
+
+BigNumber.prototype.wadDiv = function (a: BigNumber): BigNumber {
+  const halfA = a.div(2);
+  return halfA.add(this.mul(this.wad())).div(a);
+};
+
+BigNumber.prototype.rayMul = function (a: BigNumber): BigNumber {
+  return this.halfRay().add(this.mul(a)).div(this.ray());
+};
+
+BigNumber.prototype.rayDiv = function (a: BigNumber): BigNumber {
+  const halfA = a.div(2);
+  return halfA.add(this.mul(this.ray())).div(a);
+};
+
+BigNumber.prototype.percentMul = function (b: BigNumber): BigNumber {
+  return this.halfPercentage().add(this.mul(b)).div(this.percentageFactor());
+};
+
+BigNumber.prototype.percentDiv = function (a: BigNumber): BigNumber {
+  const halfA = a.div(2);
+  return halfA.add(this.mul(this.percentageFactor())).div(a);
+};
+
+BigNumber.prototype.rayToWad = function (): BigNumber {
+  const halfRatio = BigNumber.from(WAD_RAY_RATIO).div(2);
+  return halfRatio.add(this).div(WAD_RAY_RATIO);
+};
+
+BigNumber.prototype.wadToRay = function (): BigNumber {
+  return this.mul(WAD_RAY_RATIO);
+};