fix(router-sdk): Address wrapped/native currency conditions in mixed …

…routes with v4 (#81)

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

@@ -72,7 +72,7 @@ describe('MixedRoute', () => {
       expect(route.chainId).toEqual(1)
     })
 
-    it('wraps mixed route object with v4 route successfully constructs a pth from the tokens', () => {
+    it('wraps mixed route object with v4 route successfully constructs a path from the tokens', () => {
       const route = new MixedRouteSDK([pool_v3_0_1, pool_v4_0_weth], token1, weth)
       expect(route.pools).toEqual([pool_v3_0_1, pool_v4_0_weth])
       expect(route.path).toEqual([token1, token0, weth])
@@ -81,6 +81,32 @@ describe('MixedRoute', () => {
       expect(route.chainId).toEqual(1)
     })
 
+    it('wraps mixed route object with mixed v4 route that converts WETH -> ETH ', () => {
+      const route = new MixedRouteSDK([pool_v3_0_weth, pool_v4_1_eth], token0, token1)
+      expect(route.pools).toEqual([pool_v3_0_weth, pool_v4_1_eth])
+      expect(route.path).toEqual([token0, weth, token1])
+      expect(route.input).toEqual(token0)
+      expect(route.output).toEqual(token1)
+      expect(route.chainId).toEqual(1)
+    })
+
+    it('wraps mixed route object with mixed v4 route that converts ETH -> WETH ', () => {
+      const route = new MixedRouteSDK([pool_v4_1_eth, pool_v3_0_weth], token1, token0)
+      expect(route.pools).toEqual([pool_v4_1_eth, pool_v3_0_weth])
+      expect(route.path).toEqual([token1, ETHER, token0])
+      expect(route.input).toEqual(token1)
+      expect(route.output).toEqual(token0)
+      expect(route.chainId).toEqual(1)
+    })
+
+    it('cannot wrap mixed route object with pure v4 route that converts ETH -> WETH ', () => {
+      expect(() => new MixedRouteSDK([pool_v4_1_eth, pool_v4_0_weth], token1, token0)).toThrow('PATH')
+    })
+
+    it('cannot wrap mixed route object with pure v4 route that converts WETH -> ETH ', () => {
+      expect(() => new MixedRouteSDK([pool_v4_0_weth, pool_v4_1_eth], token0, token1)).toThrow('PATH')
+    })
+
     it('wraps complex mixed route object and successfully constructs a path from the tokens', () => {
       const route = new MixedRouteSDK([pool_v3_0_1, pair_1_weth, pair_weth_2], token0, token2)
       expect(route.pools).toEqual([pool_v3_0_1, pair_1_weth, pair_weth_2])

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

@@ -4,6 +4,7 @@ import { Currency, Price, 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 { isValidTokenPath } from '../../utils/isValidTokenPath'
 
 type TPool = Pair | V3Pool | V4Pool
 
@@ -52,11 +53,16 @@ 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]
-    for (const [i, pool] of pools.entries()) {
-      const currentInputToken = tokenPath[i]
-      invariant(currentInputToken.equals(pool.token0) || currentInputToken.equals(pool.token1), 'PATH')
-      const nextToken = currentInputToken.equals(pool.token0) ? pool.token1 : pool.token0
-      tokenPath.push(nextToken)
+    pools[0].token0.equals(this.adjustedInput) ? tokenPath.push(pools[0].token1) : tokenPath.push(pools[0].token0)
+
+    for (let i = 1; i < pools.length; i++) {
+      const prevPool = pools[i - 1]
+      const pool = pools[i]
+      const inputToken = tokenPath[i]
+      const outputToken = pool.token0.wrapped.equals(inputToken.wrapped) ? pool.token1 : pool.token0
+
+      invariant(isValidTokenPath(prevPool, pool, inputToken), 'PATH')
+      tokenPath.push(outputToken)
     }
 
     this.pools = pools

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

@@ -57,6 +57,11 @@ describe('MixedRouteTrade', () => {
     CurrencyAmount.fromRawAmount(WETH9[1], 130000),
     true
   )
+  const pool_v4_0_eth = v2StylePool(
+    CurrencyAmount.fromRawAmount(token0, 120000),
+    CurrencyAmount.fromRawAmount(ETHER, 130000),
+    true
+  )
 
   const pool_v3_0_1 = v2StylePool(
     CurrencyAmount.fromRawAmount(token0, 100000),
@@ -1381,7 +1386,7 @@ describe('MixedRouteTrade', () => {
   })
 
   describe('multihop v2 + v3 + v4', () => {
-    it('can be constructed with an eth output from a v4 pool', async () => {
+    it('can be constructed with a weth output from a v4 pool', async () => {
       const trade = await MixedRouteTrade.fromRoute(
         new MixedRouteSDK([pool_v3_0_1, pool_v4_0_weth], token1, WETH9[1]),
         CurrencyAmount.fromRawAmount(token1, JSBI.BigInt(100)),
@@ -1390,5 +1395,55 @@ describe('MixedRouteTrade', () => {
       expect(trade.inputAmount.currency).toEqual(token1)
       expect(trade.outputAmount.currency).toEqual(WETH9[1])
     })
+
+    it('can be constructed with an eth output from a v4 pool', async () => {
+      const trade = await MixedRouteTrade.fromRoute(
+        new MixedRouteSDK([pool_v3_0_1, pool_v4_0_eth], token1, ETHER),
+        CurrencyAmount.fromRawAmount(token1, JSBI.BigInt(100)),
+        TradeType.EXACT_INPUT
+      )
+      expect(trade.inputAmount.currency).toEqual(token1)
+      expect(trade.outputAmount.currency).toEqual(ETHER)
+    })
+
+    it('can be constructed with an eth output from a v4 weth pool', async () => {
+      const trade = await MixedRouteTrade.fromRoute(
+        new MixedRouteSDK([pool_v3_0_1, pool_v4_0_weth], token1, ETHER),
+        CurrencyAmount.fromRawAmount(token1, JSBI.BigInt(100)),
+        TradeType.EXACT_INPUT
+      )
+      expect(trade.inputAmount.currency).toEqual(token1)
+      expect(trade.outputAmount.currency).toEqual(ETHER)
+    })
+
+    it('can be constructed with an intermediate conversion WETH->ETH when trading to v4 pool', async () => {
+      const trade = await MixedRouteTrade.fromRoute(
+        new MixedRouteSDK([pool_v3_weth_0, pool_v4_0_eth], token0, ETHER),
+        CurrencyAmount.fromRawAmount(token0, JSBI.BigInt(100)),
+        TradeType.EXACT_INPUT
+      )
+      expect(trade.inputAmount.currency).toEqual(token0)
+      expect(trade.outputAmount.currency).toEqual(ETHER)
+    })
+
+    it('can be constructed with an intermediate conversion ETH->WETH when trading from a v4 pool', async () => {
+      const trade = await MixedRouteTrade.fromRoute(
+        new MixedRouteSDK([pool_v4_0_eth, pool_v3_weth_0], token0, WETH9[1]),
+        CurrencyAmount.fromRawAmount(token0, JSBI.BigInt(100)),
+        TradeType.EXACT_INPUT
+      )
+      expect(trade.inputAmount.currency).toEqual(token0)
+      expect(trade.outputAmount.currency).toEqual(WETH9[1])
+    })
+
+    it('can be constructed with an intermediate conversion ETH->WETH when trading from a v4 pool with ETH output', async () => {
+      const trade = await MixedRouteTrade.fromRoute(
+        new MixedRouteSDK([pool_v4_0_eth, pool_v3_weth_0], token0, ETHER),
+        CurrencyAmount.fromRawAmount(token0, JSBI.BigInt(100)),
+        TradeType.EXACT_INPUT
+      )
+      expect(trade.inputAmount.currency).toEqual(token0)
+      expect(trade.outputAmount.currency).toEqual(ETHER)
+    })
   })
 })

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

@@ -12,9 +12,14 @@ export async function getOutputAmount(
   if (pool instanceof V4Pool) {
     if (pool.involvesCurrency(amountIn.currency)) {
       return await pool.getOutputAmount(amountIn)
-    } else if (pool.involvesCurrency(amountIn.currency.wrapped)) {
-      return await pool.getOutputAmount(amountIn.wrapped)
+    }
+    if (pool.token0.wrapped.equals(amountIn.currency)) {
+      return await pool.getOutputAmount(CurrencyAmount.fromRawAmount(pool.token0, amountIn.quotient))
+    }
+    if (pool.token1.wrapped.equals(amountIn.currency)) {
+      return await pool.getOutputAmount(CurrencyAmount.fromRawAmount(pool.token1, amountIn.quotient))
     }
   }
+
   return await pool.getOutputAmount(amountIn.wrapped)
 }

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

@@ -0,0 +1,25 @@
+import { Currency, Token } from '@uniswap/sdk-core'
+import { Pool as V4Pool } from '@uniswap/v4-sdk'
+import { Pair } from '@uniswap/v2-sdk'
+import { Pool as V3Pool } from '@uniswap/v3-sdk'
+
+type TPool = Pair | V3Pool | V4Pool
+
+export function isValidTokenPath(prevPool: TPool, currentPool: TPool, inputToken: Currency): boolean {
+  if (currentPool.involvesToken(inputToken as Token)) return true
+
+  // throw if both v4 pools, native/wrapped tokens not interchangeable in v4
+  if (prevPool instanceof V4Pool && currentPool instanceof V4Pool) return false
+
+  // v2/v3 --> v4 valid if v2/v3 output is the wrapped version of the v4 pool native currency
+  if (currentPool instanceof V4Pool) {
+    if (currentPool.token0.wrapped.equals(inputToken) || currentPool.token1.wrapped.equals(inputToken)) return true
+  }
+
+  // v4 --> v2/v3 valid if v4 output is the native version of the v2/v3 wrapped token
+  if (prevPool instanceof V4Pool) {
+    if (currentPool.involvesToken(inputToken.wrapped)) return true
+  }
+
+  return false
+}