fix: Add safety check in createTokenBridge

src/createTokenBridge.integration.test.ts

@@ -436,4 +436,50 @@ describe('createTokenBridge', () => {
     checkTokenBridgeContracts(tokenBridgeContracts);
     checkWethGateways(tokenBridgeContracts, { customFeeToken: true });
   });
+
+  it('should throw when createTokenBridge is called multiple times', async () => {
+    const testnodeInformation = getInformationFromTestnode();
+
+    const tokenBridgeCreator = await deployTokenBridgeCreator({
+      publicClient: nitroTestnodeL1Client,
+    });
+
+    const cfg = {
+      rollupOwner: l2RollupOwner.address,
+      rollupAddress: testnodeInformation.rollup,
+      account: l2RollupOwner,
+      parentChainPublicClient: nitroTestnodeL1Client,
+      orbitChainPublicClient: nitroTestnodeL2Client,
+      tokenBridgeCreatorAddressOverride: tokenBridgeCreator,
+      gasOverrides: {
+        gasLimit: {
+          base: 6_000_000n,
+        },
+      },
+      retryableGasOverrides: {
+        maxGasForFactory: {
+          base: 20_000_000n,
+        },
+        maxGasForContracts: {
+          base: 20_000_000n,
+        },
+        maxSubmissionCostForFactory: {
+          base: 4_000_000_000_000n,
+        },
+        maxSubmissionCostForContracts: {
+          base: 4_000_000_000_000n,
+        },
+      },
+      setWethGatewayGasOverrides: {
+        gasLimit: {
+          base: 100_000n,
+        },
+      },
+    };
+    const { tokenBridgeContracts } = await createTokenBridge(cfg);
+    await expect(createTokenBridge(cfg)).rejects.toThrow();
+
+    checkTokenBridgeContracts(tokenBridgeContracts);
+    checkWethGateways(tokenBridgeContracts, { customFeeToken: false });
+  });
 });

src/createTokenBridge.ts

@@ -34,6 +34,56 @@ import { isCustomFeeTokenAddress } from './utils/isCustomFeeTokenAddress';
 import { WithTokenBridgeCreatorAddressOverride } from './types/createTokenBridgeTypes';
 import { TransactionRequestGasOverrides } from './utils/gasOverrides';
 import { getBlockExplorerUrl } from './utils/getBlockExplorerUrl';
+import { tokenBridgeCreatorABI } from './contracts/TokenBridgeCreator';
+import { getTokenBridgeCreatorAddress } from './utils';
+import { rollupABI } from './contracts/Rollup';
+
+/**
+ * If token bridge was already deployed, `createTokenBridge` will fail when waiting for retryables.
+ * This function allows us to assert that token bridge wasn't deployed.
+ *
+ * @param {String} assertTokenBridgeDoesntExistParams.parentChainPublicClient - The parent chain Viem Public Client
+ * @param {String} assertTokenBridgeDoesntExistParams.orbitChainPublicClient - The orbit chain Viem Public Client
+ * @param {String=} assertTokenBridgeDoesntExistParams.tokenBridgeCreatorAddress - The TokenBridgeCreator address.
+ * Default to getTokenBridgeCreatorAddress(parentChainPublicClient) if not provided
+ * @param {String} assertTokenBridgeDoesntExistParams.rollupAddress - The address of the rollup on the parent chain
+ *
+ * @throws if token bridge was already deployed, it throws an error
+ */
+export async function assertTokenBridgeDoesntExist<
+  TParentChain extends Chain | undefined,
+  TOrbitChain extends Chain | undefined,
+>({
+  parentChainPublicClient,
+  orbitChainPublicClient,
+  tokenBridgeCreatorAddress,
+  rollupAddress,
+}: {
+  parentChainPublicClient: PublicClient<Transport, TParentChain>;
+  orbitChainPublicClient: PublicClient<Transport, TOrbitChain>;
+  tokenBridgeCreatorAddress?: Address;
+  rollupAddress: Address;
+}) {
+  const inbox = await parentChainPublicClient.readContract({
+    address: rollupAddress,
+    abi: rollupABI,
+    functionName: 'inbox',
+  });
+
+  const [router] = await parentChainPublicClient.readContract({
+    address: tokenBridgeCreatorAddress ?? getTokenBridgeCreatorAddress(parentChainPublicClient),
+    abi: tokenBridgeCreatorABI,
+    functionName: 'inboxToL2Deployment',
+    args: [inbox],
+  });
+
+  if (router) {
+    const code = await orbitChainPublicClient.getBytecode({ address: router });
+    if (code) {
+      throw new Error('Token bridge was already deployed');
+    }
+  }
+}
 
 export type CreateTokenBridgeParams<
   TParentChain extends Chain | undefined,
@@ -171,6 +221,13 @@ export async function createTokenBridge<
 }: CreateTokenBridgeParams<TParentChain, TOrbitChain>): Promise<
   CreateTokenBridgeResults<TParentChain, TOrbitChain>
 > {
+  await assertTokenBridgeDoesntExist({
+    parentChainPublicClient,
+    orbitChainPublicClient,
+    tokenBridgeCreatorAddress: tokenBridgeCreatorAddressOverride,
+    rollupAddress,
+  });
+
   const isCustomFeeTokenBridge = isCustomFeeTokenAddress(nativeTokenAddress);
   if (isCustomFeeTokenBridge) {
     // set the custom fee token

src/index.ts

@@ -80,6 +80,7 @@ import {
   CreateTokenBridgeParams,
   CreateTokenBridgeResults,
   createTokenBridge,
+  assertTokenBridgeDoesntExist,
 } from './createTokenBridge';
 import {
   createTokenBridgeEnoughCustomFeeTokenAllowance,
@@ -210,6 +211,7 @@ export {
   prepareKeyset,
   utils,
   //
+  assertTokenBridgeDoesntExist,
   CreateTokenBridgeParams,
   CreateTokenBridgeResults,
   createTokenBridge,