[NOCHANGELOG] [Add Funds Widget] Create fetch Balances function (#2243)

packages/checkout/widgets-lib/src/widgets/add-funds/functions/fetchBalances.ts

@@ -0,0 +1,25 @@
+import { Web3Provider } from '@ethersproject/providers';
+import { Squid } from '@0xsquid/sdk';
+import { CosmosBalance, TokenBalance } from '@0xsquid/sdk/dist/types';
+import { Chain } from '../types';
+
+export const fetchBalances = async (squid: Squid, chains: Chain[], provider: Web3Provider)
+: Promise<TokenBalance[]> => {
+  const chainIds = chains.map((chain) => chain.id);
+  const address = await provider?.getSigner().getAddress();
+
+  const promises: Promise<{
+    cosmosBalances?: CosmosBalance[];
+    evmBalances?: TokenBalance[];
+  }>[] = [];
+
+  for (const chainId of chainIds) {
+    const balancePromise = squid.getAllBalances({ chainIds: [chainId], evmAddress: address });
+    promises.push(balancePromise);
+  }
+
+  const balances = await Promise.all(promises);
+  return balances
+    .flatMap((balance) => balance.evmBalances ?? [])
+    .filter((balance) => balance.balance !== '0');
+};