fix(router-sdk): Prepare router-sdk to fully support mixed routes (#135)

sdks/router-sdk/src/entities/mixedRoute/route.test.ts

@@ -78,6 +78,8 @@ describe('MixedRoute', () => {
       expect(route.path).toEqual([token1, token0, weth])
       expect(route.input).toEqual(token1)
       expect(route.output).toEqual(weth)
+      expect(route.pathInput).toEqual(token1)
+      expect(route.pathOutput).toEqual(weth)
       expect(route.chainId).toEqual(1)
     })
 
@@ -87,6 +89,8 @@ describe('MixedRoute', () => {
       expect(route.path).toEqual([token0, weth, token1])
       expect(route.input).toEqual(token0)
       expect(route.output).toEqual(token1)
+      expect(route.pathInput).toEqual(token0)
+      expect(route.pathOutput).toEqual(token1)
       expect(route.chainId).toEqual(1)
     })
 
@@ -125,6 +129,17 @@ describe('MixedRoute', () => {
       expect(route.chainId).toEqual(1)
     })
 
+    it('wraps complex mixed route object that unwraps WETH to ETH at the end', () => {
+      const route = new MixedRouteSDK([pool_v3_0_1, pool_v3_1_weth], token0, ETHER)
+      expect(route.pools).toEqual([pool_v3_0_1, pool_v3_1_weth])
+      expect(route.path).toEqual([token0, token1, weth])
+      expect(route.input).toEqual(token0)
+      expect(route.output).toEqual(ETHER)
+      expect(route.pathInput).toEqual(token0)
+      expect(route.pathOutput).toEqual(weth)
+      expect(route.chainId).toEqual(1)
+    })
+
     it('wraps complex mixed route object with multihop V2 in the beginning and constructs a path', () => {
       const route = new MixedRouteSDK([pair_0_1, pair_1_weth, pool_v3_2_weth], token0, token2)
       expect(route.pools).toEqual([pair_0_1, pair_1_weth, pool_v3_2_weth])
@@ -463,6 +478,7 @@ describe('MixedRoute', () => {
       const route = new MixedRouteSDK([pool_v3_0_1], token0, token1)
       expect(partitionMixedRouteByProtocol(route)).toStrictEqual([[pool_v3_0_1]])
     })
+
     it('returns correct for single pool', () => {
       const route = new MixedRouteSDK([pair_0_1], token0, token1)
       expect(partitionMixedRouteByProtocol(route)).toStrictEqual([[pair_0_1]])
@@ -492,6 +508,7 @@ describe('MixedRoute', () => {
       })
       expect(result[2][0]).toStrictEqual(pool_v3_2_3)
     })
+
     it('consecutive pair at the end', () => {
       const route: MixedRouteSDK<Currency, Currency> = new MixedRouteSDK(
         [pool_v3_0_1, pair_1_weth, pair_weth_2, pair_2_3],
@@ -506,6 +523,7 @@ describe('MixedRoute', () => {
         expect(pair).toStrictEqual(referenceSecondPart[i])
       })
     })
+
     it('consecutive pair at the beginning', () => {
       const route: MixedRouteSDK<Currency, Currency> = new MixedRouteSDK(
         [pair_0_1, pair_1_weth, pair_weth_2, pool_v3_2_3],
@@ -520,5 +538,23 @@ describe('MixedRoute', () => {
       })
       expect(result[1][0]).toStrictEqual(pool_v3_2_3)
     })
+
+    it('returns correct for route with V4Pool', () => {
+      const route: MixedRouteSDK<Currency, Currency> = new MixedRouteSDK(
+        [pool_v4_0_1, pool_v4_1_eth, pair_weth_2, pool_v3_2_3],
+        token0,
+        token3
+      )
+
+      const result = partitionMixedRouteByProtocol(route)
+      expect(result.length).toEqual(3)
+      expect(result[0].length).toEqual(2)
+      expect(result[1].length).toEqual(1)
+      expect(result[2].length).toEqual(1)
+      expect(result[0][0]).toStrictEqual(pool_v4_0_1)
+      expect(result[0][1]).toStrictEqual(pool_v4_1_eth)
+      expect(result[1][0]).toStrictEqual(pair_weth_2)
+      expect(result[2][0]).toStrictEqual(pool_v3_2_3)
+    })
   })
 })

sdks/router-sdk/src/entities/mixedRoute/route.ts

@@ -2,6 +2,7 @@ import invariant from 'tiny-invariant'
 import { Currency, Price, Token } from '@uniswap/sdk-core'
 import { Pool as V4Pool } from '@uniswap/v4-sdk'
 import { isValidTokenPath } from '../../utils/isValidTokenPath'
+import { getPathCurrency } from '../../utils/pathCurrency'
 import { TPool } from '../../utils/TPool'
 
 /**
@@ -14,7 +15,8 @@ export class MixedRouteSDK<TInput extends Currency, TOutput extends Currency> {
   public readonly path: Currency[]
   public readonly input: TInput
   public readonly output: TOutput
-  public readonly adjustedInput: Currency // routes with v2/v3 initial pool must wrap native input currency before trading
+  public readonly pathInput: Currency // routes may need to wrap/unwrap a currency to begin trading path
+  public readonly pathOutput: Currency // routes may need to wrap/unwrap a currency at the end of trading path
 
   private _midPrice: Price<TInput, TOutput> | null = null
 
@@ -31,13 +33,10 @@ export class MixedRouteSDK<TInput extends Currency, TOutput extends Currency> {
     const allOnSameChain = pools.every((pool) => pool.chainId === chainId)
     invariant(allOnSameChain, 'CHAIN_IDS')
 
-    if (pools[0] instanceof V4Pool) {
-      this.adjustedInput = pools[0].involvesToken(input) ? input : input.wrapped
-    } else {
-      this.adjustedInput = input.wrapped // no native currencies in v2/v3
-    }
+    this.pathInput = getPathCurrency(input, pools[0])
+    this.pathOutput = getPathCurrency(output, pools[pools.length - 1])
 
-    invariant(pools[0].involvesToken(this.adjustedInput as Token), 'INPUT')
+    invariant(pools[0].involvesToken(this.pathInput as Token), 'INPUT')
     const lastPool = pools[pools.length - 1]
     if (lastPool instanceof V4Pool) {
       invariant(lastPool.involvesToken(output) || lastPool.involvesToken(output.wrapped), 'OUTPUT')
@@ -48,8 +47,8 @@ export class MixedRouteSDK<TInput extends Currency, TOutput extends Currency> {
     /**
      * Normalizes token0-token1 order and selects the next token/fee step to add to the path
      * */
-    const tokenPath: Currency[] = [this.adjustedInput]
-    pools[0].token0.equals(this.adjustedInput) ? tokenPath.push(pools[0].token1) : tokenPath.push(pools[0].token0)
+    const tokenPath: Currency[] = [this.pathInput]
+    pools[0].token0.equals(this.pathInput) ? tokenPath.push(pools[0].token1) : tokenPath.push(pools[0].token0)
 
     for (let i = 1; i < pools.length; i++) {
       const prevPool = pools[i - 1]
@@ -90,7 +89,7 @@ export class MixedRouteSDK<TInput extends Currency, TOutput extends Currency> {
             }
       },
 
-      this.pools[0].token0.equals(this.adjustedInput)
+      this.pools[0].token0.equals(this.pathInput)
         ? {
             nextInput: this.pools[0].token1,
             price: this.pools[0].token0Price.asFraction,

sdks/router-sdk/src/entities/mixedRoute/trade.ts

@@ -1,11 +1,11 @@
-import { Currency, Fraction, Percent, Price, sortedInsert, CurrencyAmount, TradeType } from '@uniswap/sdk-core'
+import { Currency, Fraction, Percent, Price, sortedInsert, CurrencyAmount, TradeType, Token } from '@uniswap/sdk-core'
 import { Pair } from '@uniswap/v2-sdk'
 import { BestTradeOptions, Pool as V3Pool } from '@uniswap/v3-sdk'
 import { Pool as V4Pool } from '@uniswap/v4-sdk'
 import invariant from 'tiny-invariant'
 import { ONE, ZERO } from '../../constants'
 import { MixedRouteSDK } from './route'
-import { getOutputAmount } from '../../utils/getOutputAmount'
+import { amountWithPathCurrency } from '../../utils/pathCurrency'
 import { TPool } from '../../utils/TPool'
 
 /**
@@ -203,10 +203,12 @@ export class MixedRouteTrade<TInput extends Currency, TOutput extends Currency,
     invariant(tradeType === TradeType.EXACT_INPUT, 'TRADE_TYPE')
     invariant(amount.currency.equals(route.input), 'INPUT')
 
-    amounts[0] = route.pools[0] instanceof V4Pool ? amount : amount.wrapped
+    amounts[0] = amountWithPathCurrency(amount, route.pools[0])
     for (let i = 0; i < route.path.length - 1; i++) {
       const pool = route.pools[i]
-      const [outputAmount] = await getOutputAmount(pool, amounts[i])
+      const [outputAmount] = await pool.getOutputAmount(
+        amountWithPathCurrency(amounts[i], pool) as CurrencyAmount<Token>
+      )
       amounts[i + 1] = outputAmount
     }
 
@@ -255,11 +257,13 @@ export class MixedRouteTrade<TInput extends Currency, TOutput extends Currency,
 
       invariant(amount.currency.equals(route.input), 'INPUT')
       inputAmount = CurrencyAmount.fromFractionalAmount(route.input, amount.numerator, amount.denominator)
-      amounts[0] = CurrencyAmount.fromFractionalAmount(route.adjustedInput, amount.numerator, amount.denominator)
+      amounts[0] = CurrencyAmount.fromFractionalAmount(route.pathInput, amount.numerator, amount.denominator)
 
       for (let i = 0; i < route.path.length - 1; i++) {
         const pool = route.pools[i]
-        const [outputAmount] = await getOutputAmount(pool, amounts[i])
+        const [outputAmount] = await pool.getOutputAmount(
+          amountWithPathCurrency(amounts[i], pool) as CurrencyAmount<Token>
+        )
         amounts[i + 1] = outputAmount
       }
 

sdks/router-sdk/src/utils/encodeMixedRouteToPath.ts

@@ -26,9 +26,9 @@ export function encodeMixedRouteToPath(route: MixedRouteSDK<Currency, Currency>)
   let types: string[]
 
   if (containsV4Pool) {
-    path = [route.adjustedInput.isNative ? ADDRESS_ZERO : route.adjustedInput.address]
+    path = [route.pathInput.isNative ? ADDRESS_ZERO : route.pathInput.address]
     types = ['address']
-    let currencyIn = route.adjustedInput
+    let currencyIn = route.pathInput
 
     for (const pool of route.pools) {
       const currencyOut = currencyIn.equals(pool.token0) ? pool.token1 : pool.token0

sdks/router-sdk/src/utils/index.ts

@@ -1,6 +1,7 @@
 import { Currency, Token } from '@uniswap/sdk-core'
 import { Pair } from '@uniswap/v2-sdk'
 import { Pool as V3Pool } from '@uniswap/v3-sdk'
+import { Pool as V4Pool } from '@uniswap/v4-sdk'
 import { MixedRouteSDK } from '../entities/mixedRoute/route'
 import { TPool } from './TPool'
 
@@ -16,8 +17,9 @@ export const partitionMixedRouteByProtocol = (route: MixedRouteSDK<Currency, Cur
   let right = 0
   while (right < route.pools.length) {
     if (
-      (route.pools[left] instanceof V3Pool && route.pools[right] instanceof Pair) ||
-      (route.pools[left] instanceof Pair && route.pools[right] instanceof V3Pool)
+      (route.pools[left] instanceof V4Pool && !(route.pools[right] instanceof V4Pool)) ||
+      (route.pools[left] instanceof V3Pool && !(route.pools[right] instanceof V3Pool)) ||
+      (route.pools[left] instanceof Pair && !(route.pools[right] instanceof Pair))
     ) {
       acc.push(route.pools.slice(left, right))
       left = right

sdks/router-sdk/src/utils/pathCurrency.ts

@@ -0,0 +1,36 @@
+import { Currency, CurrencyAmount, Token } from '@uniswap/sdk-core'
+import { Pool as V4Pool } from '@uniswap/v4-sdk'
+import { TPool } from './TPool'
+
+export function amountWithPathCurrency(amount: CurrencyAmount<Currency>, pool: TPool): CurrencyAmount<Currency> {
+  return CurrencyAmount.fromFractionalAmount(
+    getPathCurrency(amount.currency, pool),
+    amount.numerator,
+    amount.denominator
+  )
+}
+
+export function getPathCurrency(currency: Currency, pool: TPool): Currency {
+  // return currency if the currency matches a currency of the pool
+  if (pool.involvesToken(currency as Token)) {
+    return currency
+
+    // return if currency.wrapped if pool involves wrapped currency
+  } else if (pool.involvesToken(currency.wrapped as Token)) {
+    return currency.wrapped
+
+    // return native currency if pool involves native version of wrapped currency (only applies to V4)
+  } else if (pool instanceof V4Pool) {
+    if (pool.currency0.wrapped.equals(currency)) {
+      return pool.token0
+    } else if (pool.token1.wrapped.equals(currency)) {
+      return pool.token1
+    }
+
+    // otherwise the token is invalid
+  } else {
+    throw new Error(`Expected currency ${currency.symbol} to be either ${pool.token0.symbol} or ${pool.token1.symbol}`)
+  }
+
+  return currency // this line needed for typescript to compile
+}