encode swap+add with mint/increaseliquidity (Uniswap#18)

+ includes outputTokenPermit

Author: ewilz

package.json

@@ -28,7 +28,7 @@
   "dependencies": {
     "@ethersproject/abi": "^5.5.0",
     "@uniswap/sdk-core": "^3.0.1",
-    "@uniswap/swap-router-contracts": "1.0.0",
+    "@uniswap/swap-router-contracts": "1.1.0",
     "@uniswap/v2-sdk": "^3.0.1",
     "@uniswap/v3-sdk": "^3.7.1"
   },

src/approveAndCall.ts

@@ -1,8 +1,17 @@
 import { Interface } from '@ethersproject/abi'
 import invariant from 'tiny-invariant'
 import { abi } from '@uniswap/swap-router-contracts/artifacts/contracts/interfaces/IApproveAndCall.sol/IApproveAndCall.json'
-import { Currency, Token } from '@uniswap/sdk-core'
-import { NonfungiblePositionManager } from '@uniswap/v3-sdk'
+import { Currency, Percent, Token } from '@uniswap/sdk-core'
+import {
+  MintSpecificOptions,
+  IncreaseSpecificOptions,
+  NonfungiblePositionManager,
+  Position,
+  toHex,
+} from '@uniswap/v3-sdk'
+
+// condensed version of v3-sdk AddLiquidityOptions containing only necessary swap + add attributes
+export type CondensedAddLiquidityOptions = Omit<MintSpecificOptions, 'createPool'> | IncreaseSpecificOptions
 
 export enum ApprovalTypes {
   NOT_REQUIRED = 0,
@@ -12,6 +21,11 @@ export enum ApprovalTypes {
   ZERO_THEN_MAX_MINUS_ONE = 4,
 }
 
+// type guard
+export function isMint(options: CondensedAddLiquidityOptions): options is Omit<MintSpecificOptions, 'createPool'> {
+  return Object.keys(options).some((k) => k === 'recipient')
+}
+
 export abstract class ApproveAndCall {
   public static INTERFACE: Interface = new Interface(abi)
 
@@ -47,6 +61,39 @@ export abstract class ApproveAndCall {
     }
   }
 
+  public static encodeAddLiquidity(
+    position: Position,
+    addLiquidityOptions: CondensedAddLiquidityOptions,
+    slippageTolerance: Percent
+  ): string {
+    const { amount0: amount0Min, amount1: amount1Min } = position.mintAmountsWithSlippage(slippageTolerance)
+
+    if (isMint(addLiquidityOptions)) {
+      return ApproveAndCall.INTERFACE.encodeFunctionData('mint', [
+        {
+          token0: position.pool.token0.address,
+          token1: position.pool.token1.address,
+          fee: position.pool.fee,
+          tickLower: position.tickLower,
+          tickUpper: position.tickUpper,
+          amount0Min: toHex(amount0Min),
+          amount1Min: toHex(amount1Min),
+          recipient: addLiquidityOptions.recipient,
+        },
+      ])
+    } else {
+      return ApproveAndCall.INTERFACE.encodeFunctionData('increaseLiquidity', [
+        {
+          token0: position.pool.token0.address,
+          token1: position.pool.token1.address,
+          amount0Min: toHex(amount0Min),
+          amount1Min: toHex(amount1Min),
+          tokenId: toHex(addLiquidityOptions.tokenId),
+        },
+      ])
+    }
+  }
+
   public static encodeApprove(token: Currency, approvalType: ApprovalTypes): string {
     switch (approvalType) {
       case ApprovalTypes.MAX: