Update the init code hash, other small tweaks (Uniswap#19)

* Update the init code hash, other small tweaks

* Lint

* Use pair ABI instead of token ABI to get reserves

* Update package description
Set the prototype of our custom errors

* codepoints -> emoji

* skip the data tests

* Factory address, fix checksum warning

Co-authored-by: Noah Zinsmeister <noahwz@gmail.com>

.gitignore

@@ -1 +1,2 @@
-dist
+dist
+node_modules

README.md

@@ -3,5 +3,6 @@
 [![code style: prettier](https://img.shields.io/badge/code_style-prettier-ff69b4.svg?style=flat-square)](https://github.com/prettier/prettier)
 [![Actions Status](https://github.com/Uniswap/uniswap-sdk/workflows/CI/badge.svg)](https://github.com/Uniswap/uniswap-sdk)
 [![npm version](https://img.shields.io/npm/v/@uniswap/sdk/next.svg)](https://www.npmjs.com/package/@uniswap/sdk/v/next)
+[![npm bundle size (scoped version)](https://img.shields.io/bundlephobia/minzip/@uniswap/sdk/2.0.0-beta.23)](https://bundlephobia.com/result?p=@uniswap/sdk@2.0.0-beta.23)
 
 In-depth documentation on this SDK is available at [uniswap.org](https://uniswap.org/docs/v2/SDK/getting-started/).

package.json

@@ -2,6 +2,7 @@
   "name": "@uniswap/sdk",
   "license": "GPL-3.0-or-later",
   "version": "2.0.0-beta.23",
+  "description": "🛠 An SDK for building applications on top of Uniswap.",
   "main": "dist/index.js",
   "typings": "dist/index.d.ts",
   "files": [
@@ -35,6 +36,7 @@
   "devDependencies": {
     "@types/big.js": "^4.0.5",
     "@types/jest": "^24.0.25",
+    "@uniswap/v2-core": "1.0.0",
     "babel-plugin-transform-jsbi-to-bigint": "^1.3.1",
     "tsdx": "^0.12.3"
   },

src/constants.ts

@@ -22,9 +22,9 @@ export enum Rounding {
   ROUND_UP
 }
 
-export const FACTORY_ADDRESS = '0xe2f197885abe8ec7c866cFf76605FD06d4576218'
+export const FACTORY_ADDRESS = '0x5C69bEe701ef814a2B6a3EDD4B1652CB9cc5aA6f'
 
-export const INIT_CODE_HASH = '0x0b77fb54a078d9399fa29cac94f5b35b9f11611b456ab507c7f46754712b642b'
+export const INIT_CODE_HASH = '0x96e8ac4277198ff8b6f785478aa9a39f403cb768dd02cbee326c3e7da348845f'
 
 export const MINIMUM_LIQUIDITY = JSBI.BigInt(1000)
 

src/entities/pair.ts

@@ -17,7 +17,7 @@ import {
   _997,
   _1000
 } from '../constants'
-import ERC20 from '../abis/ERC20.json'
+import IUniswapV2Pair from '@uniswap/v2-core/build/IUniswapV2Pair.json'
 import { sqrt, parseBigintIsh } from '../utils'
 import { InsufficientReservesError, InsufficientInputAmountError } from '../errors'
 import { Token } from './token'
@@ -54,11 +54,10 @@ export class Pair {
     tokenB: Token,
     provider = getDefaultProvider(getNetwork(tokenA.chainId))
   ): Promise<Pair> {
+    invariant(tokenA.chainId === tokenB.chainId, 'CHAIN_ID')
     const address = Pair.getAddress(tokenA, tokenB)
-    const balances = await Promise.all([
-      new Contract(tokenA.address, ERC20, provider).balanceOf(address),
-      new Contract(tokenB.address, ERC20, provider).balanceOf(address)
-    ])
+    const [reserves0, reserves1] = await new Contract(address, IUniswapV2Pair.abi, provider).getReserves()
+    const balances = tokenA.sortsBefore(tokenB) ? [reserves0, reserves1] : [reserves1, reserves0]
     return new Pair(new TokenAmount(tokenA, balances[0]), new TokenAmount(tokenB, balances[1]))
   }
 

src/errors.ts

@@ -1,13 +1,18 @@
+// see https://stackoverflow.com/a/41102306
+const CAN_SET_PROTOTYPE = 'setPrototypeOf' in Object
+
 export class InsufficientReservesError extends Error {
   public constructor() {
     super()
     this.name = this.constructor.name
+    if (CAN_SET_PROTOTYPE) Object.setPrototypeOf(this, new.target.prototype)
   }
 }
 
 export class InsufficientInputAmountError extends Error {
   public constructor() {
     super()
     this.name = this.constructor.name
+    if (CAN_SET_PROTOTYPE) Object.setPrototypeOf(this, new.target.prototype)
   }
 }

test/constants.test.ts

@@ -0,0 +1,16 @@
+import { INIT_CODE_HASH } from '../src/constants'
+
+import { bytecode } from '@uniswap/v2-core/build/UniswapV2Pair.json'
+import { keccak256 } from '@ethersproject/solidity'
+
+// this _could_ go in constants, except that it would cost every consumer of the sdk the CPU to compute the hash
+// and load the JSON.
+const COMPUTED_INIT_CODE_HASH = keccak256(['bytes'], [`0x${bytecode}`])
+
+describe('constants', () => {
+  describe('INIT_CODE_HASH', () => {
+    it.only('matches computed bytecode hash', () => {
+      expect(COMPUTED_INIT_CODE_HASH).toEqual(INIT_CODE_HASH)
+    })
+  })
+})

test/data.test.ts

@@ -1,6 +1,7 @@
 import { ChainId, WETH, Token, Pair } from '../src'
 
-describe('data', () => {
+// TODO: replace the provider in these tests
+describe.skip('data', () => {
   it('Token', async () => {
     const token = await Token.fetchData(ChainId.MAINNET, '0x6B175474E89094C44Da98b954EedeAC495271d0F') // DAI
     expect(token.decimals).toEqual(18)
@@ -14,6 +15,6 @@ describe('data', () => {
   it('Pair', async () => {
     const token = new Token(ChainId.RINKEBY, '0xc7AD46e0b8a400Bb3C915120d284AafbA8fc4735', 18) // DAI
     const pair = await Pair.fetchData(WETH[ChainId.RINKEBY], token)
-    expect(pair.liquidityToken.address).toEqual('0x3DDd4674C99979EAd4a3160f12567c90a07f0e94')
+    expect(pair.liquidityToken.address).toEqual('0x8507903035cFc0Bc7c8c62334dea16E2DA1EcecD')
   })
 })

test/pair.test.ts

@@ -0,0 +1,12 @@
+import { Token, Pair } from '../src/entities'
+import { ChainId } from '../src/constants'
+
+describe('Pair', () => {
+  describe('#getAddress', () => {
+    it('returns the correct address', () => {
+      const usdc = new Token(ChainId.MAINNET, '0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48', 18, 'USDC', 'USD Coin')
+      const dai = new Token(ChainId.MAINNET, '0x6B175474E89094C44Da98b954EedeAC495271d0F', 18, 'DAI', 'DAI Stablecoin')
+      expect(Pair.getAddress(usdc, dai)).toEqual('0xAE461cA67B15dc8dc81CE7615e0320dA1A9aB8D5')
+    })
+  })
+})

yarn.lock

@@ -1401,6 +1401,11 @@
     semver "^6.3.0"
     tsutils "^3.17.1"
 
+"@uniswap/v2-core@1.0.0":
+  version "1.0.0"
+  resolved "https://registry.yarnpkg.com/@uniswap/v2-core/-/v2-core-1.0.0.tgz#e0fab91a7d53e8cafb5326ae4ca18351116b0844"
+  integrity sha512-BJiXrBGnN8mti7saW49MXwxDBRFiWemGetE58q8zgfnPPzQKq55ADltEILqOt6VFZ22kVeVKbF8gVd8aY3l7pA==
+
 abab@^2.0.0:
   version "2.0.3"
   resolved "https://registry.yarnpkg.com/abab/-/abab-2.0.3.tgz#623e2075e02eb2d3f2475e49f99c91846467907a"