contracts-bedrock: Add tests for xdm pausability

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

+// SPDX-License-Identifier: MIT
+pragma solidity 0.8.15;
+
+import { CommonTest } from "test/setup/CommonTest.sol";
+import { SuperchainConfig } from "src/L1/SuperchainConfig.sol";
+
+contract ExtendedPause_Test is CommonTest {
+    /// @dev Tests that other contracts are paused when the superchain config is paused
+    ///      This test is somewhat redundant with tests in the SuperchainConfig and other pausable contracts, however
+    ///      it is worthwhile to pull them into one location to ensure that the behavior is consistent.
+    function test_pause_fullSystem_succeeds() external {
+        assertFalse(superchainConfig.paused());
+        assertEq(l1CrossDomainMessenger.paused(), superchainConfig.paused());
+
+        vm.prank(superchainConfig.guardian());
+        superchainConfig.pause("identifier");
+
+        assertTrue(superchainConfig.paused());
+        assertEq(l1CrossDomainMessenger.paused(), superchainConfig.paused());
+
+        // The following is hacky approach which ensures that this test will fail if the paused() function is
+        // added to the L1StandardBridge or the L1ERC721Bridge. At that point this test should be updated to include
+        // those methods.
+        try SuperchainConfig(address(l1StandardBridge)).paused() {
+            revert("The L1StandardBridge has a paused() function, but is not tested as part of the ExtendedPause");
+        } catch (bytes memory) {
+            assertTrue(true);
+        }
+        try SuperchainConfig(address(l1ERC721Bridge)).paused() {
+            revert("The L1ERC721Bridge has a paused() function, but is not tested as part of the ExtendedPause");
+        } catch (bytes memory) {
+            assertTrue(true);
+        }
+    }
+}

packages/contracts-bedrock/test/L1CrossDomainMessenger.t.sol

@@ -13,6 +13,7 @@ import { Encoding } from "src/libraries/Encoding.sol";
 
 // Target contract dependencies
 import { OptimismPortal } from "src/L1/OptimismPortal.sol";
+import { SuperchainConfig } from "src/L1/SuperchainConfig.sol";
 
 contract L1CrossDomainMessenger_Test is Bridge_Initializer {
     /// @dev The receiver address
@@ -558,4 +559,39 @@ contract L1CrossDomainMessenger_Test is Bridge_Initializer {
             hex"1111"
         );
     }
+
+    /// @dev Tests that the relayMessage function is able to relay a message
+    ///      successfully by calling the target contract.
+    function test_relayMessage_paused_reverts() external {
+        vm.prank(superchainConfig.guardian());
+        superchainConfig.pause("identifier");
+        vm.expectRevert("CrossDomainMessenger: paused");
+
+        l1CrossDomainMessenger.relayMessage(
+            Encoding.encodeVersionedNonce({ _nonce: 0, _version: 1 }), // nonce
+            address(0),
+            address(0),
+            0, // value
+            0,
+            hex"1111"
+        );
+    }
+
+    /// @dev Tests that the superchain config is called by the messengers paused function
+    function test_pause_callsSuperchainConfig_succeeds() external {
+        vm.expectCall(address(superchainConfig), abi.encodeWithSelector(SuperchainConfig.paused.selector));
+        l1CrossDomainMessenger.paused();
+    }
+
+    /// @dev Tests that changing the superchain config paused status changes the return value of the messenger
+    function test_pause_matchesSuperchainConfig_succeeds() external {
+        assertFalse(l1CrossDomainMessenger.paused());
+        assertEq(l1CrossDomainMessenger.paused(), superchainConfig.paused());
+
+        vm.prank(superchainConfig.guardian());
+        superchainConfig.pause("identifier");
+
+        assertTrue(l1CrossDomainMessenger.paused());
+        assertEq(l1CrossDomainMessenger.paused(), superchainConfig.paused());
+    }
 }