feat: Add trustline creation to the borrow flow.

currencies.ts

@@ -8,6 +8,7 @@ export type Currency = {
   ticker: SupportedCurrency;
   tokenContractAddress: string;
   loanPoolName: string;
+  issuer?: string;
 };
 
 // The addresses here are for testnet.
@@ -25,27 +26,31 @@ export const CURRENCY_WBTC: Currency = {
   ticker: 'wBTC',
   tokenContractAddress: 'CAP5AMC2OHNVREO66DFIN6DHJMPOBAJ2KCDDIMFBR7WWJH5RZBFM3UEI',
   loanPoolName: 'pool_wbtc',
+  issuer: 'GATALTGTWIOT6BUDBCZM3Q4OQ4BO2COLOAZ7IYSKPLC2PMSOPPGF5V56',
 } as const;
 
 export const CURRENCY_WETH: Currency = {
   name: 'Ethereum',
   ticker: 'wETH',
   tokenContractAddress: 'CAZAQB3D7KSLSNOSQKYD2V4JP5V2Y3B4RDJZRLBFCCIXDCTE3WHSY3UE',
   loanPoolName: 'pool_weth',
+  issuer: 'GATALTGTWIOT6BUDBCZM3Q4OQ4BO2COLOAZ7IYSKPLC2PMSOPPGF5V56',
 } as const;
 
 export const CURRENCY_USDC: Currency = {
   name: 'USD Coin',
   ticker: 'USDC',
   tokenContractAddress: 'CBIELTK6YBZJU5UP2WWQEUCYKLPU6AUNZ2BQ4WWFEIE3USCIHMXQDAMA',
   loanPoolName: 'pool_usdc',
+  issuer: 'GBBD47IF6LWK7P7MDEVSCWR7DPUWV3NY3DTQEVFL4NAT4AQH3ZLLFLA5',
 } as const;
 
 export const CURRENCY_EURC: Currency = {
   name: 'Euro Coin',
   ticker: 'EURC',
   tokenContractAddress: 'CCUUDM434BMZMYWYDITHFXHDMIVTGGD6T2I5UKNX5BSLXLW7HVR4MCGZ',
   loanPoolName: 'pool_eurc',
+  issuer: 'GB3Q6QDZYTHWT7E5PVS3W7FUT5GVAFC5KSZFFLPU25GO7VTC3NM2ZTVO',
 } as const;
 
 export const CURRENCIES: Currency[] = [

src/components/CryptoAmountSelector.tsx

@@ -78,7 +78,7 @@ export const CryptoAmountSelector = ({
 const TickerOption = ({ ticker }: { ticker: SupportedCurrency }) => {
   const { walletBalances } = useWallet();
   const balance = walletBalances?.[ticker];
-  const disabled = isNil(balance) || !balance.trustline || isBalanceZero(balance.balanceLine.balance);
+  const disabled = isNil(balance) || !balance.trustLine || isBalanceZero(balance.balanceLine.balance);
 
   return (
     <option disabled={disabled} value={ticker}>

src/lib/horizon.ts

@@ -0,0 +1,34 @@
+import { Asset, Horizon, Networks, Operation, type Transaction, TransactionBuilder } from '@stellar/stellar-sdk';
+import type { XDR_BASE64 } from '@stellar/stellar-sdk/contract';
+import type { Currency } from 'currencies';
+
+const HorizonServer = new Horizon.Server('https://horizon-testnet.stellar.org/');
+
+export const getBalances = async (account: string): Promise<Horizon.HorizonApi.BalanceLine[]> => {
+  const { balances } = await HorizonServer.loadAccount(account);
+  return balances;
+};
+
+export const createAddTrustlineTransaction = async (
+  account: string,
+  { ticker, issuer }: Currency,
+): Promise<Transaction> => {
+  const asset = new Asset(ticker, issuer);
+
+  const sourceAccount = await HorizonServer.loadAccount(account);
+
+  const transaction = new TransactionBuilder(sourceAccount, {
+    networkPassphrase: Networks.TESTNET,
+    fee: '100000',
+  })
+    .addOperation(Operation.changeTrust({ asset }))
+    .setTimeout(300) // 5 minutes timeout
+    .build();
+
+  return transaction;
+};
+
+export const sendTransaction = async (txXdr: XDR_BASE64): Promise<Horizon.HorizonApi.SubmitTransactionResponse> => {
+  const tx = TransactionBuilder.fromXDR(txXdr, Networks.TESTNET);
+  return HorizonServer.submitTransaction(tx);
+};

src/pages/_borrow/BorrowModal.tsx

@@ -1,11 +1,11 @@
-import * as StellarSdk from '@stellar/stellar-sdk'
 import { Warning } from '@components/Alert';
 import { Button } from '@components/Button';
 import { CryptoAmountSelector } from '@components/CryptoAmountSelector';
 import { Loading } from '@components/Loading';
 import { contractClient as loanManagerClient } from '@contracts/loan_manager';
 import { getIntegerPart, to7decimals } from '@lib/converters';
 import { SCALAR_7, fromCents, toCents } from '@lib/formatting';
+import { createAddTrustlineTransaction, sendTransaction } from '@lib/horizon';
 import type { SupportedCurrency } from 'currencies';
 import { type ChangeEvent, useState } from 'react';
 import { CURRENCY_BINDINGS, CURRENCY_BINDINGS_ARR, type CurrencyBinding } from 'src/currency-bindings';
@@ -37,8 +37,8 @@ export const BorrowModal = ({ modalId, onClose, currency, totalSupplied }: Borro
     ({ ticker }) => ticker,
   );
 
-  // The modal is impossible to open before the balances load.
-  if (!walletBalances) return null;
+  // The modal is impossible to open without a wallet or before the balances load.
+  if (!wallet || !walletBalances) return null;
 
   const loanBalance = walletBalances[ticker];
   const collateralBalance = walletBalances[collateralTicker];
@@ -55,7 +55,7 @@ export const BorrowModal = ({ modalId, onClose, currency, totalSupplied }: Borro
     loanAmountCents && loanAmountCents > 0n ? Number(collateralAmountCents) / Number(loanAmountCents) : 0;
 
   // The modal is impossible to open without collateral balance.
-  if (!collateralBalance.trustline) return null;
+  if (!collateralBalance.trustLine) return null;
 
   const closeModal = () => {
     refetchBalances();
@@ -64,6 +64,12 @@ export const BorrowModal = ({ modalId, onClose, currency, totalSupplied }: Borro
     onClose();
   };
 
+  const handleAddTrustlineClick = async () => {
+    const tx = await createAddTrustlineTransaction(wallet.address, currency);
+    const signedTx = await signTransaction(tx.toXDR());
+    sendTransaction(signedTx);
+  };
+
   const handleBorrowClick = async () => {
     if (!wallet) {
       alert('Please connect your wallet first!');
@@ -81,8 +87,6 @@ export const BorrowModal = ({ modalId, onClose, currency, totalSupplied }: Borro
 
       const { contractId: collateralCurrencyId } = CURRENCY_BINDINGS[collateralTicker];
 
-
-
       const tx = await loanManagerClient.create_loan({
         user: wallet.address,
         borrowed: to7decimals(loanAmount),
@@ -126,7 +130,7 @@ export const BorrowModal = ({ modalId, onClose, currency, totalSupplied }: Borro
     setCollateralAmount('0');
   };
 
-  const isTrustline = loanBalance.trustline;
+  const isTrustline = loanBalance.trustLine;
 
   const isBorrowDisabled =
     !isTrustline || loanAmount === '0' || collateralAmount === '0' || healthFactor < HEALTH_FACTOR_MIN_THRESHOLD;
@@ -149,6 +153,7 @@ export const BorrowModal = ({ modalId, onClose, currency, totalSupplied }: Borro
         {!isTrustline ? (
           <Warning>
             <span>Create a trustline for {ticker} in your wallet first!</span>
+            <Button onClick={handleAddTrustlineClick}>Add trustline</Button>
           </Warning>
         ) : null}
         <p className="my-4">

src/pages/_borrow/BorrowableAsset.tsx

@@ -28,7 +28,7 @@ export const BorrowableAsset = ({ currency }: BorrowableAssetCardProps) => {
     ? false
     : Object.entries(walletBalances)
         .filter(([t, _b]) => t !== ticker)
-        .some(([_t, b]) => b.trustline && !isBalanceZero(b.balanceLine.balance));
+        .some(([_t, b]) => b.trustLine && !isBalanceZero(b.balanceLine.balance));
 
   const borrowDisabled = !wallet || !isCollateral || !totalSupplied;
 
@@ -66,7 +66,7 @@ export const BorrowableAsset = ({ currency }: BorrowableAssetCardProps) => {
       const { result } = await loanManagerClient.get_price({ token: currency.ticker });
       setTotalSuppliedPrice(result);
     } catch (error) {
-      console.error('Error fetchin price data:', error);
+      console.error('Error fetching price data:', error);
     }
   }, [currency.ticker]);
 

src/stellar-wallet.tsx

@@ -1,21 +1,20 @@
 import { FREIGHTER_ID, StellarWalletsKit, WalletNetwork, allowAllModules } from '@creit.tech/stellar-wallets-kit';
-import * as StellarSdk from '@stellar/stellar-sdk';
+import type * as StellarSdk from '@stellar/stellar-sdk';
 import { type PropsWithChildren, createContext, useContext, useEffect, useState } from 'react';
 
 import { contractClient as loanManagerClient } from '@contracts/loan_manager';
+import { getBalances } from '@lib/horizon';
 import { type SupportedCurrency, isSupportedCurrency } from 'currencies';
 import { CURRENCY_BINDINGS_ARR } from './currency-bindings';
 
-const HorizonServer = new StellarSdk.Horizon.Server('https://horizon-testnet.stellar.org/');
-
 export type Wallet = {
   address: string;
   displayName: string;
 };
 
 export type Balance =
-  | { trustline: false }
-  | { trustline: true; balanceLine: StellarSdk.Horizon.HorizonApi.BalanceLine };
+  | { trustLine: false }
+  | { trustLine: true; balanceLine: StellarSdk.Horizon.HorizonApi.BalanceLine };
 
 export type BalanceRecord = {
   [K in SupportedCurrency]: Balance;
@@ -61,8 +60,8 @@ const Context = createContext<WalletContext>({
   walletBalances: null,
   positions: {},
   prices: null,
-  createConnectWalletButton: () => { },
-  refetchBalances: () => { },
+  createConnectWalletButton: () => {},
+  refetchBalances: () => {},
   signTransaction: () => Promise.reject(),
 });
 
@@ -91,18 +90,18 @@ const createBalanceRecord = (balances: StellarSdk.Horizon.HorizonApi.BalanceLine
   balances.reduce(
     (acc, balanceLine) => {
       if (balanceLine.asset_type === 'native') {
-        acc.XLM = { trustline: true, balanceLine };
+        acc.XLM = { trustLine: true, balanceLine };
       } else if (balanceLine.asset_type === 'credit_alphanum4' && isSupportedCurrency(balanceLine.asset_code)) {
-        acc[balanceLine.asset_code] = { trustline: true, balanceLine };
+        acc[balanceLine.asset_code] = { trustLine: true, balanceLine };
       }
       return acc;
     },
     {
-      XLM: { trustline: false },
-      wBTC: { trustline: false },
-      wETH: { trustline: false },
-      USDC: { trustline: false },
-      EURC: { trustline: false },
+      XLM: { trustLine: false },
+      wBTC: { trustLine: false },
+      wETH: { trustLine: false },
+      USDC: { trustLine: false },
+      EURC: { trustLine: false },
     } as BalanceRecord,
   );
 
@@ -122,7 +121,7 @@ const fetchPriceData = async (token: string): Promise<bigint> => {
     const { result } = await loanManagerClient.get_price({ token });
     return result;
   } catch (error) {
-    console.error('Error fetching price data:', error);
+    console.error(`Error fetching price data: for ${token}`, error);
     return 0n;
   }
 };
@@ -135,7 +134,7 @@ export const WalletProvider = ({ children }: PropsWithChildren) => {
 
   const setWallet = async (address: string) => {
     setAddress(address);
-    const { balances } = await HorizonServer.loadAccount(address);
+    const balances = await getBalances(address);
     setWalletBalances(createBalanceRecord(balances));
     setPositions(await fetchAllPositions(address));
   };
@@ -172,7 +171,7 @@ export const WalletProvider = ({ children }: PropsWithChildren) => {
     if (!address) return;
 
     try {
-      const { balances } = await HorizonServer.loadAccount(address);
+      const balances = await getBalances(address);
       setWalletBalances(createBalanceRecord(balances));
       const positions = await fetchAllPositions(address);
       setPositions(positions);