Make domainHash internal as _domainHash, publicly expose in TestMultisigValidatorManager

solidity/core/contracts/test/TestMultisigValidatorManager.sol

@@ -17,4 +17,13 @@ contract TestMultisigValidatorManager is MultisigValidatorManager {
     )
         MultisigValidatorManager(_outboxDomain, _validatorSet, _quorumThreshold)
     {}
+
+    /**
+     * @notice Hash of domain concatenated with "ABACUS".
+     * @dev This is a public getter of _domainHash to test with.
+     * @param _domain The domain to hash.
+     */
+    function domainHash(uint32 _domain) external pure returns (bytes32) {
+        return _domainHash(_domain);
+    }
 }

solidity/core/contracts/validator-manager/MultisigValidatorManager.sol

@@ -68,7 +68,7 @@ abstract contract MultisigValidatorManager is Ownable {
     ) Ownable() {
         // Set immutables.
         outboxDomain = _outboxDomain;
-        outboxDomainHash = domainHash(_outboxDomain);
+        outboxDomainHash = _domainHash(_outboxDomain);
 
         // Enroll validators. Reverts if there are any duplicates.
         uint256 _validatorSetLength = _validatorSet.length;
@@ -169,14 +169,6 @@ abstract contract MultisigValidatorManager is Ownable {
         return _validatorSignatureCount >= quorumThreshold;
     }
 
-    /**
-     * @notice Hash of domain concatenated with "ABACUS".
-     * @param _domain The domain to hash.
-     */
-    function domainHash(uint32 _domain) public pure returns (bytes32) {
-        return keccak256(abi.encodePacked(_domain, "ABACUS"));
-    }
-
     // ============ Internal Functions ============
 
     /**
@@ -236,4 +228,12 @@ abstract contract MultisigValidatorManager is Ownable {
         quorumThreshold = _quorumThreshold;
         emit SetQuorumThreshold(_quorumThreshold);
     }
+
+    /**
+     * @notice Hash of domain concatenated with "ABACUS".
+     * @param _domain The domain to hash.
+     */
+    function _domainHash(uint32 _domain) internal pure returns (bytes32) {
+        return keccak256(abi.encodePacked(_domain, "ABACUS"));
+    }
 }

solidity/core/test/validator-manager/multisigValidatorManager.test.ts

@@ -246,12 +246,14 @@ describe('MultisigValidatorManager', async () => {
     });
   });
 
-  describe('#domainHash', () => {
+  describe('#_domainHash', () => {
     it('matches Rust-produced domain hashes', async () => {
       // Compare Rust output in json file to solidity output (json file matches
       // hash for local domain of 1000)
       for (let testCase of domainHashTestCases) {
         const { expectedDomainHash } = testCase;
+        // This public function on TestMultisigValidatorManager exposes
+        // the internal _domainHash on MultisigValidatorManager.
         const domainHash = await validatorManager.domainHash(
           testCase.outboxDomain,
         );