fix(swap): handle minimum egress amount (#767)

CHANGELOG.md

@@ -22,6 +22,9 @@ which it is deprecated.
 - `SwapSDK.prototype.executeSwap` allows to not wait for transaction inclusion
   by passing `{ wait: 0 }` as `txOpts` param now. The method will return the
   transaction hash of the submitted transaction.
+- Liquidity fees have been moved from the `includedFees` property on the
+  `getQuote` response, into a new `poolInfo` property, which is an array of the
+  pools the swap passes through, along with the estimated fee and fee asset.
 
 ### Fixed
 
@@ -42,6 +45,40 @@ which it is deprecated.
 - `SwapSDK.prototype.requestDepositAddress` supports an optional `brokerCommissionBps`
   and `affiliateBrokers` option. The new options are only available when initializing
   the SDK with a brokerUrl and will be applied only to the requested deposit channel.
+- Support for Arbitrum tokens have been added.
+- Arbitrum ETH and USDC have been added to the `ChainAssetMap` type:
+
+```diff
+type ChainAssetMap<T> = {
+  Bitcoin: {
+    BTC: T;
+  };
+  Ethereum: {
+    ETH: T;
+    USDC: T;
+    FLIP: T;
+    USDT: T;
+  };
+  Polkadot: {
+    DOT: T;
+  };
++ Arbitrum: {
++   ETH: T;
++   USDC: T
++ };
+}
+```
+
+- Arbitrum has also been added to our `ChainMap` type:
+
+```diff
+type ChainMap<T> = {
+  Bitcoin: T;
+  Ethereum: T;
+  Polkadot: T;
++ Arbitrum: T;
+}
+```
 
 ## 1.3.0
 
@@ -64,18 +101,18 @@ which it is deprecated.
 
 ```diff
 type ChainAssetMap<T> = {
-    Bitcoin: {
-        BTC: T;
-    };
-    Ethereum: {
-        ETH: T;
-        USDC: T;
-        FLIP: T;
-+       USDT: T;
-    };
-    Polkadot: {
-        DOT: T;
-    };
+  Bitcoin: {
+    BTC: T;
+  };
+  Ethereum: {
+    ETH: T;
+    USDC: T;
+    FLIP: T;
++   USDT: T;
+  };
+  Polkadot: {
+    DOT: T;
+  };
 }
 ```
 

packages/swap/src/routes/__tests__/quote.test.ts

@@ -263,7 +263,7 @@ describe('server', () => {
         network_fee: buildFee('Usdc', 2000000).bigint,
         ingress_fee: buildFee('Usdc', 2000000).bigint,
         intermediary: null,
-        output: BigInt(0),
+        output: 0n,
       } as CfSwapRateV2);
 
       const params = new URLSearchParams({
@@ -278,7 +278,33 @@ describe('server', () => {
 
       expect(status).toBe(400);
       expect(body).toMatchObject({
-        message: 'egress amount (0) is lower than minimum egress amount (1)',
+        message: 'swap output amount is lower than the egress fee (50000)',
+      });
+      expect(sendSpy).toHaveBeenCalledTimes(1);
+    });
+
+    it('rejects when the egress amount is smaller than the minimum egress amount', async () => {
+      const sendSpy = jest.spyOn(WsClient.prototype, 'sendRequest').mockResolvedValueOnce({
+        egress_fee: buildFee('Eth', 25000).bigint,
+        network_fee: buildFee('Usdc', 2000000).bigint,
+        ingress_fee: buildFee('Usdc', 2000000).bigint,
+        intermediary: null,
+        output: 599n,
+      } as CfSwapRateV2);
+
+      const params = new URLSearchParams({
+        srcChain: 'Ethereum',
+        srcAsset: 'ETH',
+        destChain: 'Bitcoin',
+        destAsset: 'BTC',
+        amount: (100e6).toString(),
+      });
+
+      const { body, status } = await request(server).get(`/quote?${params.toString()}`);
+
+      expect(status).toBe(400);
+      expect(body).toMatchObject({
+        message: 'egress amount (599) is lower than minimum egress amount (600)',
       });
       expect(sendSpy).toHaveBeenCalledTimes(1);
     });

packages/swap/src/utils/getPoolQuote.ts

@@ -3,7 +3,7 @@ import { getPipAmountFromAmount } from '@/shared/functions';
 import { QuoteQueryResponse } from '@/shared/schemas';
 import { estimateSwapDuration } from '@/swap/utils/swap';
 import { buildFee, getPoolFees } from './fees';
-import { getMinimumEgressAmount } from './rpc';
+import { getEgressFee, getMinimumEgressAmount } from './rpc';
 import ServiceError from './ServiceError';
 import { LimitOrders, getSwapRateV2 } from './statechain';
 import { InternalAsset, Pool } from '../client';
@@ -60,6 +60,13 @@ export default async function getPoolQuote({
       throw ServiceError.badRequest('swap amount is lower than ingress fee');
     }
 
+    const rpcEgressFee = await getEgressFee(destAsset);
+    throw ServiceError.badRequest(
+      `swap output amount is lower than the egress fee (${rpcEgressFee})`,
+    );
+  }
+
+  if (quote.outputAmount < minimumEgressAmount) {
     throw ServiceError.badRequest(
       `egress amount (${quote.outputAmount}) is lower than minimum egress amount (${minimumEgressAmount})`,
     );