Feat: [TP-1627] Add support for swapping ERC20s into native tokens (#…

…1078)

Co-authored-by: Pano Skylakis <[email protected]>

packages/internal/dex/sdk/src/exchange.getUnsignedSwapTxFromAmountOut.test.ts

@@ -35,6 +35,7 @@ import {
  WIMX_TEST_TOKEN,
  expectToBeString,
  refundETHFunctionSignature,
+ NATIVE_TEST_TOKEN,
 } from './test/utils';
 
 jest.mock('@ethersproject/providers');
@@ -366,6 +367,136 @@ describe('getUnsignedSwapTxFromAmountOut', () => {
  expect(decodedRefundEthTx.length).toEqual(0); // expect that the refundETH call has no parameters
  });
  });
+
+ describe('when the output token is native', () => {
+ it('should not include any amount as the value of the transaction', async () => {
+ mockRouterImplementation({
+ pools: [createPool(nativeTokenService.wrappedToken, FUN_TEST_TOKEN)],
+ });
+
+ const exchange = new Exchange(TEST_DEX_CONFIGURATION);
+
+ const { swap } = await exchange.getUnsignedSwapTxFromAmountOut(
+ TEST_FROM_ADDRESS,
+ FUN_TEST_TOKEN.address,
+ 'native',
+ newAmountFromString('100', NATIVE_TEST_TOKEN).value,
+ );
+
+ expectToBeDefined(swap.transaction.data);
+ expectToBeDefined(swap.transaction.value);
+ const data = swap.transaction.data.toString();
+
+ const { swapParams } = decodeMulticallExactOutputSingleWithoutFees(data);
+ expectInstanceOf(BigNumber, swapParams.amountOut);
+
+ expect(swapParams.tokenIn).toBe(FUN_TEST_TOKEN.address); // should be the token-in
+ expect(swapParams.tokenOut).toBe(WIMX_TEST_TOKEN.address); // should be the wrapped native token
+ expect(swap.transaction.value).toBe('0x00'); // should not have a value
+ });
+
+ it('should include a call to unwrapWETH9 as the final method call of the calldata', async () => {
+ mockRouterImplementation({
+ pools: [createPool(nativeTokenService.wrappedToken, FUN_TEST_TOKEN)],
+ });
+
+ const swapRouterInterface = SwapRouter.INTERFACE;
+ const paymentsInterface = PaymentsExtended.INTERFACE;
+ const exchange = new Exchange(TEST_DEX_CONFIGURATION);
+
+ // Buy 100 native tokens for X amount of FUN where the exchange rate is 1 token-in : 10 token-out
+ const { swap } = await exchange.getUnsignedSwapTxFromAmountOut(
+ TEST_FROM_ADDRESS,
+ FUN_TEST_TOKEN.address,
+ 'native',
+ newAmountFromString('100', NATIVE_TEST_TOKEN).value,
+ 3, // 3 % slippage
+ );
+
+ expectToBeDefined(swap.transaction.data);
+ expectToBeDefined(swap.transaction.value);
+ const calldata = swap.transaction.data.toString();
+
+ const topLevelParams = swapRouterInterface.decodeFunctionData('multicall(uint256,bytes[])', calldata);
+
+ expect(topLevelParams.data.length).toBe(2); // expect that there are two calls in the multicall
+ const swapFunctionCalldata = topLevelParams.data[0];
+ const unwrapWETHFunctionCalldata = topLevelParams.data[1];
+
+ expectToBeString(swapFunctionCalldata);
+ expectToBeString(unwrapWETHFunctionCalldata);
+
+ // Get the first 4 bytes of the swap and unwrap function calldata to get the function selector
+ const swapFunctionFragment = swapRouterInterface.getFunction(swapFunctionCalldata.slice(0, 10));
+ const unwrapFunctionFragment = paymentsInterface.getFunction(unwrapWETHFunctionCalldata.slice(0, 10));
+
+ expect(swapFunctionFragment.name).toEqual('exactOutputSingle');
+ expect(unwrapFunctionFragment.name).toEqual('unwrapWETH9');
+ });
+
+ it('should specify the Router contract as the recipient of the swap function call', async () => {
+ mockRouterImplementation({
+ pools: [createPool(nativeTokenService.wrappedToken, FUN_TEST_TOKEN)],
+ });
+
+ const exchange = new Exchange(TEST_DEX_CONFIGURATION);
+
+ // Buy 100 native tokens for X amount of FUN where the exchange rate is 1 token-in : 10 token-out
+ const { swap } = await exchange.getUnsignedSwapTxFromAmountOut(
+ TEST_FROM_ADDRESS,
+ FUN_TEST_TOKEN.address,
+ 'native',
+ newAmountFromString('100', NATIVE_TEST_TOKEN).value,
+ 3, // 3 % slippage
+ );
+
+ expectToBeDefined(swap.transaction.data);
+ expectToBeDefined(swap.transaction.value);
+
+ const { swapParams } = decodeMulticallExactOutputSingleWithoutFees(swap.transaction.data);
+
+ expect(swapParams.recipient).toEqual(TEST_ROUTER_ADDRESS);
+ });
+
+ it('should specify the quoted amount with slippage applied in the unwrapWETH9 function calldata', async () => {
+ mockRouterImplementation({
+ pools: [createPool(nativeTokenService.wrappedToken, FUN_TEST_TOKEN)],
+ });
+
+ const swapRouterInterface = SwapRouter.INTERFACE;
+ const paymentsInterface = PaymentsExtended.INTERFACE;
+ const exchange = new Exchange(TEST_DEX_CONFIGURATION);
+
+ // Buy 100 native tokens for X amount of FUN where the exchange rate is 1 token-in : 10 token-out
+ const { swap } = await exchange.getUnsignedSwapTxFromAmountOut(
+ TEST_FROM_ADDRESS,
+ FUN_TEST_TOKEN.address,
+ 'native',
+ newAmountFromString('100', NATIVE_TEST_TOKEN).value,
+ 10, // 10 % slippage for easier test math
+ );
+
+ expectToBeDefined(swap.transaction.data);
+ expectToBeDefined(swap.transaction.value);
+ const calldata = swap.transaction.data.toString();
+
+ const topLevelParams = swapRouterInterface.decodeFunctionData('multicall(uint256,bytes[])', calldata);
+
+ expect(topLevelParams.data.length).toBe(2); // expect that there are two calls in the multicall
+ const swapFunctionCalldata = topLevelParams.data[0];
+ const unwrapWETHFunctionCalldata = topLevelParams.data[1];
+
+ expectToBeString(swapFunctionCalldata);
+ expectToBeString(unwrapWETHFunctionCalldata);
+
+ const decodedUnwrapWETH9FunctionData = paymentsInterface.decodeFunctionData(
+ 'unwrapWETH9(uint256)',
+ unwrapWETHFunctionCalldata,
+ );
+
+ expect(formatEther(decodedUnwrapWETH9FunctionData.toString())).toEqual('100.0'); // expect the user-specified amount
+ });
+ });
  });
 
  describe('Swap with multiple pools and secondary fees', () => {

packages/internal/dex/sdk/src/exchange.ts

@@ -169,6 +169,7 @@ export class Exchange {
 
  const swap = getSwap(
  tokenIn,
+ tokenOut,
  adjustedQuote,
  fromAddress,
  slippagePercent,

packages/internal/dex/sdk/src/lib/transactionUtils/swap.test.ts

@@ -72,6 +72,7 @@ describe('getSwap', () => {
 
  const swap = getSwap(
  quote.amountIn.token,
+ quote.amountOut.token,
  quote,
  makeAddr('fromAddress'),
  slippagePercentage,
@@ -95,6 +96,7 @@ describe('getSwap', () => {
 
  const swap = getSwap(
  quote.amountIn.token,
+ quote.amountOut.token,
  quote,
  makeAddr('fromAddress'),
  slippagePercentage,
@@ -120,6 +122,7 @@ describe('getSwap', () => {
 
  const swap = getSwap(
  quote.amountIn.token,
+ quote.amountOut.token,
  quote,
  makeAddr('fromAddress'),
  slippagePercentage,
@@ -143,6 +146,7 @@ describe('getSwap', () => {
 
  const swap = getSwap(
  quote.amountIn.token,
+ quote.amountOut.token,
  quote,
  makeAddr('fromAddress'),
  slippagePercentage,
@@ -164,11 +168,13 @@ describe('getSwap', () => {
  describe('with EXACT_INPUT + native amount in', () => {
  it('uses the amountSpecified as the transaction value', () => {
  const originalTokenIn = nativeTokenService.nativeToken;
+ const originalTokenOut = FUN_TEST_TOKEN;
  const quote = buildExactInputQuote(nativeTokenService.wrappedToken, FUN_TEST_TOKEN);
  quote.amountIn.value = utils.parseEther('99');
 
  const swap = getSwap(
  originalTokenIn,
+ originalTokenOut,
  quote,
  makeAddr('fromAddress'),
  slippagePercentage,
@@ -186,10 +192,12 @@ describe('getSwap', () => {
  describe('with EXACT_INPUT + native amount out', () => {
  it('sets a transaction value of zero', () => {
  const originalTokenIn = FUN_TEST_TOKEN;
+ const originalTokenOut = NATIVE_TEST_TOKEN;
  const quote = buildExactInputQuote(FUN_TEST_TOKEN, nativeTokenService.wrappedToken);
 
  const swap = getSwap(
  originalTokenIn,
+ originalTokenOut,
  quote,
  makeAddr('fromAddress'),
  slippagePercentage,
@@ -207,11 +215,13 @@ describe('getSwap', () => {
  describe('with EXACT_OUTPUT + native amount in', () => {
  it('sets the transaction value to the max amount in including slippage', () => {
  const originalTokenIn = nativeTokenService.nativeToken;
+ const originalTokenOut = FUN_TEST_TOKEN;
  const quote = buildExactOutputQuote(nativeTokenService.wrappedToken, FUN_TEST_TOKEN);
  quote.amountIn.value = utils.parseEther('100');
 
  const swap = getSwap(
  originalTokenIn,
+ originalTokenOut,
  quote,
  makeAddr('fromAddress'),
  slippagePercentage,
@@ -229,10 +239,12 @@ describe('getSwap', () => {
  describe('with EXACT_OUTPUT + native amount out', () => {
  it('sets a transaction value of zero', () => {
  const originalTokenIn = FUN_TEST_TOKEN;
+ const originalTokenOut = NATIVE_TEST_TOKEN;
  const quote = buildExactOutputQuote(FUN_TEST_TOKEN, nativeTokenService.wrappedToken);
 
  const swap = getSwap(
  originalTokenIn,
+ originalTokenOut,
  quote,
  makeAddr('fromAddress'),
  slippagePercentage,