tests: L2 bridge withdraw to calls and events :test_tube:

packages/contracts-bedrock/.gas-snapshot

@@ -171,10 +171,10 @@ L2StandardBridge_Test:test_finalizeBridgeETH_sendToSelf_reverts() (gas: 23893)
 L2StandardBridge_Test:test_finalizeDeposit_succeeds() (gas: 89473)
 L2StandardBridge_Test:test_initialize_succeeds() (gas: 24270)
 L2StandardBridge_Test:test_receive_succeeds() (gas: 166663)
-L2StandardBridge_Test:test_withdrawTo_succeeds() (gas: 352440)
+L2StandardBridge_Test:test_withdrawTo_succeeds() (gas: 384299)
 L2StandardBridge_Test:test_withdraw_insufficientValue_reverts() (gas: 19630)
 L2StandardBridge_Test:test_withdraw_notEOA_reverts() (gas: 251836)
-L2StandardBridge_Test:test_withdraw_succeeds() (gas: 382386)
+L2StandardBridge_Test:test_withdraw_succeeds() (gas: 382396)
 L2ToL1MessagePasserTest:test_burn_succeeds() (gas: 112572)
 L2ToL1MessagePasserTest:test_initiateWithdrawal_fromContract_succeeds() (gas: 70423)
 L2ToL1MessagePasserTest:test_initiateWithdrawal_fromEOA_succeeds() (gas: 75874)

packages/contracts-bedrock/contracts/test/L2StandardBridge.t.sol

@@ -213,14 +213,80 @@ contract L2StandardBridge_Test is Bridge_Initializer {
     // - calls Withdrawer.initiateWithdrawal
     function test_withdrawTo_succeeds() external {
         deal(address(L2Token), alice, 100, true);
+        assertEq(L2Token.balanceOf(alice), 100);
+        uint256 nonce = L2Messenger.messageNonce();
+        bytes memory message = abi.encodeWithSelector(
+            StandardBridge.finalizeBridgeERC20.selector,
+            address(L1Token),
+            address(L2Token),
+            alice,
+            bob,
+            100,
+            hex""
+        );
+        uint64 baseGas = L2Messenger.baseGas(message, 1000);
+        bytes memory withdrawalData = abi.encodeWithSelector(
+            CrossDomainMessenger.relayMessage.selector,
+            nonce,
+            address(L2Bridge),
+            address(L1Bridge),
+            0,
+            1000,
+            message
+        );
+        bytes32 withdrawalHash = Hashing.hashWithdrawal(
+            Types.WithdrawalTransaction({
+                nonce: nonce,
+                sender: address(L2Messenger),
+                target: address(L1Messenger),
+                value: 0,
+                gasLimit: baseGas,
+                data: withdrawalData
+            })
+        );
 
         vm.expectEmit(true, true, true, true);
         emit ERC20BridgeInitiated(address(L2Token), address(L1Token), alice, bob, 100, hex"");
 
+        vm.expectEmit(true, true, true, true);
+        emit MessagePassed(nonce, address(L2Messenger), address(L1Messenger), 0, baseGas, withdrawalData, withdrawalHash);
+
+        // SentMessage event emitted by the CrossDomainMessenger
+        vm.expectEmit(true, true, true, true);
+        emit SentMessage(address(L1Bridge), address(L2Bridge), message, nonce, 1000);
+
+        // SentMessageExtension1 event emitted by the CrossDomainMessenger
+        vm.expectEmit(true, true, true, true);
+        emit SentMessageExtension1(address(L2Bridge), 0);
+
         vm.expectEmit(true, true, true, true);
         emit WithdrawalInitiated(address(L1Token), address(L2Token), alice, bob, 100, hex"");
 
-        // TODO: calls
+        vm.expectCall(
+            address(L2Messenger),
+            abi.encodeWithSelector(
+                CrossDomainMessenger.sendMessage.selector,
+                address(L1Bridge),
+                message,
+                1000
+            )
+        );
+
+        vm.expectCall(
+            Predeploys.L2_TO_L1_MESSAGE_PASSER,
+            abi.encodeWithSelector(
+                L2ToL1MessagePasser.initiateWithdrawal.selector,
+                address(L1Messenger),
+                baseGas,
+                withdrawalData
+            )
+        );
+
+        // The L2Bridge should burn the tokens
+        vm.expectCall(
+            address(L2Token),
+            abi.encodeWithSelector(OptimismMintableERC20.burn.selector, alice, 100)
+        );
 
         vm.prank(alice, alice);
         L2Bridge.withdrawTo(address(L2Token), bob, 100, 1000, hex"");