use sqrt from sdk-core

package.json

@@ -24,7 +24,7 @@
   "dependencies": {
     "@ethersproject/address": "^5.0.0",
     "@ethersproject/solidity": "^5.0.0",
-    "@uniswap/sdk-core": "^1.0.8",
+    "@uniswap/sdk-core": "^1.0.9",
     "tiny-invariant": "^1.1.0",
     "tiny-warning": "^1.0.3"
   },

src/entities/pair.ts

-import { BigintIsh, ChainId, Price, Token, TokenAmount } from '@uniswap/sdk-core'
+import { BigintIsh, ChainId, Price, sqrt, Token, TokenAmount } from '@uniswap/sdk-core'
 import invariant from 'tiny-invariant'
 import JSBI from 'jsbi'
 import { pack, keccak256 } from '@ethersproject/solidity'
 import { getCreate2Address } from '@ethersproject/address'
-import babylonianSqrt from '../utils/babylonianSqrt'
 
 import { FACTORY_ADDRESS, INIT_CODE_HASH, MINIMUM_LIQUIDITY, FIVE, _997, _1000, ONE, ZERO } from '../constants'
 import { InsufficientReservesError, InsufficientInputAmountError } from '../errors'
@@ -159,10 +158,7 @@ export class Pair {
 
     let liquidity: JSBI
     if (JSBI.equal(totalSupply.raw, ZERO)) {
-      liquidity = JSBI.subtract(
-        babylonianSqrt(JSBI.multiply(tokenAmounts[0].raw, tokenAmounts[1].raw)),
-        MINIMUM_LIQUIDITY
-      )
+      liquidity = JSBI.subtract(sqrt(JSBI.multiply(tokenAmounts[0].raw, tokenAmounts[1].raw)), MINIMUM_LIQUIDITY)
     } else {
       const amount0 = JSBI.divide(JSBI.multiply(tokenAmounts[0].raw, totalSupply.raw), this.reserve0.raw)
       const amount1 = JSBI.divide(JSBI.multiply(tokenAmounts[1].raw, totalSupply.raw), this.reserve1.raw)
@@ -193,8 +189,8 @@ export class Pair {
       invariant(!!kLast, 'K_LAST')
       const kLastParsed = JSBI.BigInt(kLast)
       if (!JSBI.equal(kLastParsed, ZERO)) {
-        const rootK = babylonianSqrt(JSBI.multiply(this.reserve0.raw, this.reserve1.raw))
-        const rootKLast = babylonianSqrt(kLastParsed)
+        const rootK = sqrt(JSBI.multiply(this.reserve0.raw, this.reserve1.raw))
+        const rootKLast = sqrt(kLastParsed)
         if (JSBI.greaterThan(rootK, rootKLast)) {
           const numerator = JSBI.multiply(totalSupply.raw, JSBI.subtract(rootK, rootKLast))
           const denominator = JSBI.add(JSBI.multiply(rootK, FIVE), rootKLast)

src/utils/babylonianSqrt.test.ts

-import JSBI from 'jsbi'
-import babylonianSqrt from './babylonianSqrt'
-
-describe('#babylonianSqrt', () => {
-  it('correct for 0-1000', () => {
-    for (let i = 0; i < 1000; i++) {
-      expect(babylonianSqrt(JSBI.BigInt(i))).toEqual(JSBI.BigInt(Math.floor(Math.sqrt(i))))
-    }
-  })
-})

src/utils/babylonianSqrt.ts

-import JSBI from 'jsbi'
-
-const ZERO = JSBI.BigInt(0)
-const ONE = JSBI.BigInt(1)
-const TWO = JSBI.BigInt(2)
-const THREE = JSBI.BigInt(3)
-
-// computes floor(babylonianSqrt(y)) using the babylonian method (not the fastest way)
-export default function babylonianSqrt(y: JSBI): JSBI {
-  let z: JSBI = ZERO
-  let x: JSBI
-  if (JSBI.greaterThan(y, THREE)) {
-    z = y
-    x = JSBI.add(JSBI.divide(y, TWO), ONE)
-    while (JSBI.lessThan(x, z)) {
-      z = x
-      x = JSBI.divide(JSBI.add(JSBI.divide(y, x), x), TWO)
-    }
-  } else if (JSBI.notEqual(y, ZERO)) {
-    z = ONE
-  }
-  return z
-}

yarn.lock

@@ -1706,10 +1706,10 @@
     semver "^7.3.2"
     tsutils "^3.17.1"
 
-"@uniswap/sdk-core@^1.0.8":
-  version "1.0.8"
-  resolved "https://registry.yarnpkg.com/@uniswap/sdk-core/-/sdk-core-1.0.8.tgz#ef71021bd7f2791bdb146b740f876a4f2d89c05b"
-  integrity sha512-ted1NTEj023A501rVLdYHqvJt+abAJZPyYZKMLgQ0OGsT/rO8NCYR4kZgvwumv+c7ZlUM8jdmnkiPVH+lFc/kw==
+"@uniswap/sdk-core@^1.0.9":
+  version "1.0.9"
+  resolved "https://registry.yarnpkg.com/@uniswap/sdk-core/-/sdk-core-1.0.9.tgz#67e8d506e2c563f5183245ae9c32c54ac083479b"
+  integrity sha512-CWvDhN7mU+v786HEqAcyDhRMlLt9r6/Etgcduc36PlmmWk1Bb2XyK/UGMu/MD8cB9NlJ0h17WLx/X+CFg93ivg==
   dependencies:
     "@ethersproject/address" "^5.0.2"
     big.js "^5.2.2"