fix: improve transaction cost estimation for pay modal

.changeset/ten-rockets-stare.md

@@ -0,0 +1,5 @@
+---
+"thirdweb": patch
+---
+
+Fix tx cost estimation for pay transaction modal

packages/thirdweb/src/react/core/hooks/transaction/useSendTransaction.ts

@@ -1,14 +1,13 @@
 import { type UseMutationResult, useMutation } from "@tanstack/react-query";
 import type { Chain } from "../../../../chains/types.js";
-import { getGasPrice } from "../../../../gas/get-gas-price.js";
 import type { BuyWithCryptoStatus } from "../../../../pay/buyWithCrypto/getStatus.js";
 import type { BuyWithFiatStatus } from "../../../../pay/buyWithFiat/getStatus.js";
 import type { FiatProvider } from "../../../../pay/utils/commonTypes.js";
-import { estimateGasCost } from "../../../../transaction/actions/estimate-gas-cost.js";
 import type { GaslessOptions } from "../../../../transaction/actions/gasless/types.js";
 import { sendTransaction } from "../../../../transaction/actions/send-transaction.js";
 import type { WaitForReceiptOptions } from "../../../../transaction/actions/wait-for-tx-receipt.js";
 import type { PreparedTransaction } from "../../../../transaction/prepare-transaction.js";
+import { getTransactionGasCost } from "../../../../transaction/utils.js";
 import { resolvePromisedValue } from "../../../../utils/promise/resolve-promised-value.js";
 import type { Wallet } from "../../../../wallets/interfaces/wallet.js";
 import { getTokenBalance } from "../../../../wallets/utils/getTokenBalance.js";
@@ -215,7 +214,7 @@
                     tokenAddress: _erc20Value.tokenAddress,
                   })
                 : undefined,
-              getTotalTxCostForBuy(tx, account.address),
+              getTransactionGasCost(tx, account.address),
             ]);
 
             const gasSponsored = hasSponsoredTransactionsEnabled(wallet);
@@ -248,39 +247,3 @@
     },
   });
 }
-
-async function getTotalTxCostForBuy(tx: PreparedTransaction, from?: string) {
-  try {
-    const gasCost = await estimateGasCost({
-      transaction: tx,
-      from,
-    });
-
-    const bufferCost = gasCost.wei / 10n;
-
-    // Note: get tx.value AFTER estimateGasCost
-    const txValue = await resolvePromisedValue(tx.value);
-
-    // add 10% extra gas cost to the estimate to ensure user buys enough to cover the tx cost
-    return gasCost.wei + bufferCost + (txValue || 0n);
-  } catch {
-    if (from) {
-      // try again without passing from
-      return await getTotalTxCostForBuy(tx);
-    }
-    // fallback if both fail, use the tx value + 2M * gas price
-    const value = await resolvePromisedValue(tx.value);
-
-    const gasPrice = await getGasPrice({
-      client: tx.client,
-      chain: tx.chain,
-    });
-
-    const buffer = 2_000_000n * gasPrice;
-
-    if (!value) {
-      return 0n + buffer;
-    }
-    return value + buffer;
-  }
-}

packages/thirdweb/src/react/web/ui/ConnectWallet/screens/Buy/main/useBuyTxStates.ts

@@ -4,10 +4,9 @@ import { getChainMetadata } from "../../../../../../../chains/utils.js";
 import { NATIVE_TOKEN_ADDRESS } from "../../../../../../../constants/addresses.js";
 import { getContract } from "../../../../../../../contract/contract.js";
 import { getCurrencyMetadata } from "../../../../../../../extensions/erc20/read/getCurrencyMetadata.js";
-import { getGasPrice } from "../../../../../../../gas/get-gas-price.js";
 import { encode } from "../../../../../../../transaction/actions/encode.js";
-import { estimateGasCost } from "../../../../../../../transaction/actions/estimate-gas-cost.js";
 import type { PreparedTransaction } from "../../../../../../../transaction/prepare-transaction.js";
+import { getTransactionGasCost } from "../../../../../../../transaction/utils.js";
 import type { Hex } from "../../../../../../../utils/encoding/hex.js";
 import { resolvePromisedValue } from "../../../../../../../utils/promise/resolve-promised-value.js";
 import type { Account } from "../../../../../../../wallets/interfaces/wallet.js";
@@ -138,30 +137,3 @@ export function useTransactionCostAndData(args: {
     },
   });
 }
-
-async function getTransactionGasCost(tx: PreparedTransaction, from?: string) {
-  try {
-    const gasCost = await estimateGasCost({
-      transaction: tx,
-      from,
-    });
-
-    const bufferCost = gasCost.wei / 10n;
-
-    // Note: get tx.value AFTER estimateGasCost
-    // add 10% extra gas cost to the estimate to ensure user buys enough to cover the tx cost
-    return gasCost.wei + bufferCost;
-  } catch {
-    if (from) {
-      // try again without passing from
-      return await getTransactionGasCost(tx);
-    }
-    // fallback if both fail, use the tx value + 2M * gas price
-    const gasPrice = await getGasPrice({
-      client: tx.client,
-      chain: tx.chain,
-    });
-
-    return 2_000_000n * gasPrice;
-  }
-}

packages/thirdweb/src/transaction/utils.ts

@@ -1,4 +1,7 @@
 import type { AbiFunction } from "abitype";
+import { getGasPrice } from "../gas/get-gas-price.js";
+import { estimateGasCost } from "./actions/estimate-gas-cost.js";
+import type { PreparedTransaction } from "./prepare-transaction.js";
 
 /**
  * @internal
@@ -11,3 +14,33 @@
     item.type === "function"
   );
 }
+
+export async function getTransactionGasCost(
+  tx: PreparedTransaction,
+  from?: string,
+) {
+  try {
+    const gasCost = await estimateGasCost({
+      transaction: tx,
+      from,
+    });
+
+    const bufferCost = gasCost.wei / 10n;
+
+    // Note: get tx.value AFTER estimateGasCost
+    // add 10% extra gas cost to the estimate to ensure user buys enough to cover the tx cost
+    return gasCost.wei + bufferCost;
+  } catch {
+    if (from) {
+      // try again without passing from
+      return await getTransactionGasCost(tx);
+    }
+    // fallback if both fail, use the tx value + 1M * gas price
+    const gasPrice = await getGasPrice({
+      client: tx.client,
+      chain: tx.chain,
+    });
+
+    return 1_000_000n * gasPrice;
+  }
+}