Added CREATE fix

packages/contracts/contracts/optimistic-ethereum/OVM/execution/OVM_ExecutionManager.sol

@@ -34,7 +34,6 @@ contract OVM_ExecutionManager is iOVM_ExecutionManager {
     GlobalContext internal globalContext;
     TransactionContext internal transactionContext;
     MessageContext internal messageContext;
-
     TransactionRecord internal transactionRecord;
     MessageRecord internal messageRecord;
 
@@ -117,6 +116,7 @@ contract OVM_ExecutionManager is iOVM_ExecutionManager {
     function ovmCALLER()
         override
         public
+        view
         returns (
             address _CALLER
         )
@@ -131,6 +131,7 @@ contract OVM_ExecutionManager is iOVM_ExecutionManager {
     function ovmADDRESS()
         override
         public
+        view
         returns (
             address _ADDRESS
         )
@@ -145,6 +146,7 @@ contract OVM_ExecutionManager is iOVM_ExecutionManager {
     function ovmORIGIN()
         override
         public
+        view
         returns (
             address _ORIGIN
         )
@@ -159,6 +161,7 @@ contract OVM_ExecutionManager is iOVM_ExecutionManager {
     function ovmTIMESTAMP()
         override
         public
+        view
         returns (
             uint256 _TIMESTAMP
         )
@@ -173,6 +176,7 @@ contract OVM_ExecutionManager is iOVM_ExecutionManager {
     function ovmGASLIMIT()
         override
         public
+        view
         returns (
             uint256 _GASLIMIT
         )
@@ -187,6 +191,7 @@ contract OVM_ExecutionManager is iOVM_ExecutionManager {
     function ovmCHAINID()
         override
         public
+        view
         returns (
             uint256 _CHAINID
         )
@@ -359,7 +364,7 @@ contract OVM_ExecutionManager is iOVM_ExecutionManager {
         }
 
         // If the user already has an EOA account, then there's no need to perform this operation.
-        if (_hasAccount(eoa) == true) {
+        if (_hasEmptyAccount(eoa) == false) {
             return;
         }
 
@@ -570,7 +575,7 @@ contract OVM_ExecutionManager is iOVM_ExecutionManager {
         return Lib_EthUtils.getCode(
             _getAccountEthAddress(_contract),
             _offset,
-            _length
+            length
         );
     }
 
@@ -643,6 +648,14 @@ contract OVM_ExecutionManager is iOVM_ExecutionManager {
             return;
         }
 
+        // We need to be sure that the user isn't trying to use a contract creation to overwrite
+        // some existing contract. On L1, users will prove that no contract exists at the address
+        // and the OVM_FraudVerifier will populate the code hash of this address with a special
+        // value that represents "known to be an empty account."
+        if (_hasEmptyAccount(_address) == false) {
+            _revertWithFlag(RevertFlag.CREATE_COLLISION);
+        }
+
         // Check the creation bytecode against the OVM_SafetyChecker.
         if (ovmSafetyChecker.isBytecodeSafe(_bytecode) == false) {
             _revertWithFlag(RevertFlag.UNSAFE_BYTECODE);
@@ -863,6 +876,23 @@ contract OVM_ExecutionManager is iOVM_ExecutionManager {
         return ovmStateManager.hasAccount(_address);
     }
 
+    /**
+     * Checks whether a known empty account exists within the OVM_StateManager.
+     * @param _address Address of the account to check.
+     * @return _exists Whether or not the account empty exists.
+     */
+    function _hasEmptyAccount(
+        address _address
+    )
+        internal
+        returns (
+            bool _exists
+        )
+    {
+        _checkAccountLoad(_address);
+        return ovmStateManager.hasEmptyAccount(_address);
+    }
+
     /**
      * Sets the nonce of an account.
      * @param _address Address of the account to modify.
@@ -921,7 +951,10 @@ contract OVM_ExecutionManager is iOVM_ExecutionManager {
     )
         internal
     {
-        _checkAccountChange(_address);
+        // Although it seems like `_checkAccountChange` would be more appropriate here, we don't
+        // actually consider an account "changed" until it's inserted into the state (in this case
+        // by `_commitPendingAccount`).
+        _checkAccountLoad(_address);
         ovmStateManager.initPendingAccount(_address);
     }
 
@@ -1034,6 +1067,7 @@ contract OVM_ExecutionManager is iOVM_ExecutionManager {
         // If we hadn't already changed the account, then we'll need to charge "nuisance gas" based
         // on the size of the contract code.
         if (_wasAccountAlreadyChanged == false) {
+            ovmStateManager.incrementTotalUncommittedAccounts();
             _useNuisanceGas(
                 Lib_EthUtils.getCodeSize(_getAccountEthAddress(_address)) * NUISANCE_GAS_PER_CONTRACT_BYTE
             );
@@ -1092,6 +1126,7 @@ contract OVM_ExecutionManager is iOVM_ExecutionManager {
         // If we hadn't already changed the account, then we'll need to charge some fixed amount of
         // "nuisance gas".
         if (_wasContractStorageAlreadyChanged == false) {
+            ovmStateManager.incrementTotalUncommittedContractStorage();
             _useNuisanceGas(NUISANCE_GAS_SSTORE);
         }
     }

packages/contracts/contracts/optimistic-ethereum/OVM/execution/OVM_StateManager.sol

@@ -13,6 +13,13 @@ import { iOVM_StateManager } from "../../iOVM/execution/iOVM_StateManager.sol";
  */
 contract OVM_StateManager is iOVM_StateManager {
 
+    /**********************
+     * Contract Constants *
+     **********************/
+    
+    bytes32 constant internal EMPTY_ACCOUNT_CODE_HASH = 0x6969696969696969696969696969696969696969696969696969696969696969;
+
+
     /*******************************************
      * Contract Variables: Contract References *
      *******************************************/
@@ -111,7 +118,7 @@ contract OVM_StateManager is iOVM_StateManager {
     function getAccount(address _address)
         override
         public
-        authenticated
+        view
         returns (
             Lib_OVMCodec.Account memory _account
         )
@@ -129,7 +136,7 @@ contract OVM_StateManager is iOVM_StateManager {
     )
         override
         public
-        authenticated
+        view
         returns (
             bool _exists
         )
@@ -137,6 +144,24 @@ contract OVM_StateManager is iOVM_StateManager {
         return accounts[_address].codeHash != bytes32(0);
     }
 
+    /**
+     * Checks whether the state has a given known empty account.
+     * @param _address Address of the account to check.
+     * @return _exists Whether or not the state has the empty account.
+     */
+    function hasEmptyAccount(
+        address _address
+    )
+        override
+        public
+        view
+        returns (
+            bool _exists
+        )
+    {
+        return accounts[_address].codeHash == EMPTY_ACCOUNT_CODE_HASH;
+    }
+
     /**
      * Sets the nonce of an account.
      * @param _address Address of the account to modify.
@@ -163,7 +188,7 @@ contract OVM_StateManager is iOVM_StateManager {
     )
         override
         public
-        authenticated
+        view
         returns (
             uint256 _nonce
         )
@@ -181,7 +206,7 @@ contract OVM_StateManager is iOVM_StateManager {
     )
         override
         public
-        authenticated
+        view
         returns (
             address _ethAddress
         )
@@ -261,16 +286,10 @@ contract OVM_StateManager is iOVM_StateManager {
             bool _wasAccountAlreadyChanged
         )
     {
-        bool wasAccountAlreadyChanged = _testAndSetItemState(
+        return _testAndSetItemState(
             keccak256(abi.encodePacked(_address)),
             ItemState.ITEM_CHANGED
         );
-
-        if (!wasAccountAlreadyChanged) {
-            totalUncommittedAccounts += 1;
-        }
-
-        return wasAccountAlreadyChanged;
     }
 
     /**
@@ -299,6 +318,17 @@ contract OVM_StateManager is iOVM_StateManager {
         return true;
     }
 
+    /**
+     * Increments the total number of uncommitted accounts.
+     */
+    function incrementTotalUncommittedAccounts()
+        override
+        public
+        authenticated
+    {
+        totalUncommittedAccounts += 1;
+    }
+
     /**
      * Gets the total number of uncommitted accounts.
      * @return _total Total uncommitted accounts.
@@ -306,7 +336,7 @@ contract OVM_StateManager is iOVM_StateManager {
     function getTotalUncommittedAccounts()
         override
         public
-        authenticated
+        view
         returns (
             uint256 _total
         )
@@ -350,7 +380,7 @@ contract OVM_StateManager is iOVM_StateManager {
     )
         override
         public
-        authenticated
+        view
         returns (
             bytes32 _value
         )
@@ -370,7 +400,7 @@ contract OVM_StateManager is iOVM_StateManager {
     )
         override
         public
-        authenticated
+        view
         returns (
             bool _exists
         )
@@ -418,16 +448,10 @@ contract OVM_StateManager is iOVM_StateManager {
             bool _wasContractStorageAlreadyChanged
         )
     {
-        bool wasContractStorageAlreadyChanged = _testAndSetItemState(
+        return _testAndSetItemState(
             keccak256(abi.encodePacked(_contract, _key)),
             ItemState.ITEM_CHANGED
         );
-
-        if (!wasContractStorageAlreadyChanged) {
-            totalUncommittedContractStorage += 1;
-        }
-
-        return wasContractStorageAlreadyChanged;
     }
 
     /**
@@ -458,6 +482,17 @@ contract OVM_StateManager is iOVM_StateManager {
         return true;
     }
 
+    /**
+     * Increments the total number of uncommitted storage slots.
+     */
+    function incrementTotalUncommittedContractStorage()
+        override
+        public
+        authenticated
+    {
+        totalUncommittedContractStorage += 1;
+    }
+
     /**
      * Gets the total number of uncommitted storage slots.
      * @return _total Total uncommitted storage slots.
@@ -465,7 +500,7 @@ contract OVM_StateManager is iOVM_StateManager {
     function getTotalUncommittedContractStorage()
         override
         public
-        authenticated
+        view
         returns (
             uint256 _total
         )

packages/contracts/contracts/optimistic-ethereum/iOVM/execution/iOVM_ExecutionManager.sol

@@ -16,7 +16,8 @@ interface iOVM_ExecutionManager {
         INTENTIONAL_REVERT,
         EXCEEDS_NUISANCE_GAS,
         INVALID_STATE_ACCESS,
-        UNSAFE_BYTECODE
+        UNSAFE_BYTECODE,
+        CREATE_COLLISION
     }
 
     struct GlobalContext {
@@ -61,12 +62,12 @@ interface iOVM_ExecutionManager {
      * Context Opcodes *
      *******************/
 
-    function ovmCALLER() external returns (address _caller);
-    function ovmADDRESS() external returns (address _address);
-    function ovmORIGIN() external returns (address _origin);
-    function ovmTIMESTAMP() external returns (uint256 _timestamp);
-    function ovmGASLIMIT() external returns (uint256 _gasLimit);
-    function ovmCHAINID() external returns (uint256 _chainId);
+    function ovmCALLER() external view returns (address _caller);
+    function ovmADDRESS() external view returns (address _address);
+    function ovmORIGIN() external view returns (address _origin);
+    function ovmTIMESTAMP() external view returns (uint256 _timestamp);
+    function ovmGASLIMIT() external view returns (uint256 _gasLimit);
+    function ovmCHAINID() external view returns (uint256 _chainId);
 
 
     /*******************

packages/contracts/contracts/optimistic-ethereum/iOVM/execution/iOVM_StateManager.sol

@@ -34,17 +34,19 @@ interface iOVM_StateManager {
      ************************************/
 
     function putAccount(address _address, Lib_OVMCodec.Account memory _account) external;
-    function getAccount(address _address) external returns (Lib_OVMCodec.Account memory _account);
-    function hasAccount(address _address) external returns (bool _exists);
+    function getAccount(address _address) external view returns (Lib_OVMCodec.Account memory _account);
+    function hasAccount(address _address) external view returns (bool _exists);
+    function hasEmptyAccount(address _address) external view returns (bool _exists);
     function setAccountNonce(address _address, uint256 _nonce) external;
-    function getAccountNonce(address _address) external returns (uint256 _nonce);
-    function getAccountEthAddress(address _address) external returns (address _ethAddress);
+    function getAccountNonce(address _address) external view returns (uint256 _nonce);
+    function getAccountEthAddress(address _address) external view returns (address _ethAddress);
     function initPendingAccount(address _address) external;
     function commitPendingAccount(address _address, address _ethAddress, bytes32 _codeHash) external;
     function testAndSetAccountLoaded(address _address) external returns (bool _wasAccountAlreadyLoaded);
     function testAndSetAccountChanged(address _address) external returns (bool _wasAccountAlreadyChanged);
     function commitAccount(address _address) external returns (bool _wasAccountCommitted);
-    function getTotalUncommittedAccounts() external returns (uint256 _total);
+    function incrementTotalUncommittedAccounts() external;
+    function getTotalUncommittedAccounts() external view returns (uint256 _total);
 
     
     /************************************
@@ -52,10 +54,11 @@ interface iOVM_StateManager {
      ************************************/
 
     function putContractStorage(address _contract, bytes32 _key, bytes32 _value) external;
-    function getContractStorage(address _contract, bytes32 _key) external returns (bytes32 _value);
+    function getContractStorage(address _contract, bytes32 _key) external view returns (bytes32 _value);
     function hasContractStorage(address _contract, bytes32 _key) external returns (bool _exists);
     function testAndSetContractStorageLoaded(address _contract, bytes32 _key) external returns (bool _wasContractStorageAlreadyLoaded);
     function testAndSetContractStorageChanged(address _contract, bytes32 _key) external returns (bool _wasContractStorageAlreadyChanged);
     function commitContractStorage(address _contract, bytes32 _key) external returns (bool _wasContractStorageCommitted);
-    function getTotalUncommittedContractStorage() external returns (uint256 _total);
+    function incrementTotalUncommittedContractStorage() external;
+    function getTotalUncommittedContractStorage() external view returns (uint256 _total);
 }

packages/contracts/contracts/optimistic-ethereum/libraries/codec/Lib_OVMCodec.sol

@@ -106,6 +106,11 @@ library Lib_OVMCodec {
         });
     }
 
+    /**
+     * Encodes a standard OVM transaction.
+     * @param _transaction OVM transaction to encode.
+     * @return _encoded Encoded transaction bytes.
+     */
     function encodeTransaction(
         Transaction memory _transaction
     )
@@ -126,6 +131,11 @@ library Lib_OVMCodec {
         );
     }
 
+    /**
+     * Hashes a standard OVM transaction.
+     * @param _transaction OVM transaction to encode.
+     * @return _hash Hashed transaction
+     */
     function hashTransaction(
         Transaction memory _transaction
     )

packages/contracts/contracts/optimistic-ethereum/libraries/trie/Lib_MerkleTrie.sol

@@ -81,7 +81,7 @@ library Lib_MerkleTrie {
             bool
         )
     {
-        return verifyProof(_key, _value, _proof, _root, true);
+        return _verifyProof(_key, _value, _proof, _root, true);
     }
 
     /**
@@ -108,7 +108,7 @@ library Lib_MerkleTrie {
             bool
         )
     {
-        return verifyProof(_key, _value, _proof, _root, false);
+        return _verifyProof(_key, _value, _proof, _root, false);
     }
 
     /**
@@ -134,12 +134,12 @@ library Lib_MerkleTrie {
             bytes32
         )
     {
-        TrieNode[] memory proof = parseProof(_proof);
-        (uint256 pathLength, bytes memory keyRemainder, ) = walkNodePath(proof, _key, _root);
+        TrieNode[] memory proof = _parseProof(_proof);
+        (uint256 pathLength, bytes memory keyRemainder, ) = _walkNodePath(proof, _key, _root);
 
-        TrieNode[] memory newPath = getNewPath(proof, pathLength, keyRemainder, _value);
+        TrieNode[] memory newPath = _getNewPath(proof, pathLength, keyRemainder, _value);
 
-        return getUpdatedTrieRoot(newPath, _key);
+        return _getUpdatedTrieRoot(newPath, _key);
     }
 
     /**
@@ -161,11 +161,11 @@ library Lib_MerkleTrie {
             bytes memory
         )
     {
-        TrieNode[] memory proof = parseProof(_proof);
-        (uint256 pathLength, bytes memory keyRemainder, ) = walkNodePath(proof, _key, _root);
+        TrieNode[] memory proof = _parseProof(_proof);
+        (uint256 pathLength, bytes memory keyRemainder, ) = _walkNodePath(proof, _key, _root);
 
         bool exists = keyRemainder.length == 0;
-        bytes memory value = exists ? getNodeValue(proof[pathLength - 1]) : bytes('');
+        bytes memory value = exists ? _getNodeValue(proof[pathLength - 1]) : bytes('');
 
         return (
             exists,
@@ -189,7 +189,7 @@ library Lib_MerkleTrie {
             bytes32
         )
     {
-        return keccak256(makeLeafNode(
+        return keccak256(_makeLeafNode(
             _key,
             _value
         ).encoded);
@@ -214,7 +214,7 @@ library Lib_MerkleTrie {
      * @param _inclusion Whether to check for inclusion or exclusion.
      * @return `true` if the k/v pair is (in/not in) the trie, `false` otherwise.
      */
-    function verifyProof(
+    function _verifyProof(
         bytes memory _key,
         bytes memory _value,
         bytes memory _proof,
@@ -227,20 +227,20 @@ library Lib_MerkleTrie {
             bool
         )
     {
-        TrieNode[] memory proof = parseProof(_proof);
-        (uint256 pathLength, bytes memory keyRemainder, bool isFinalNode) = walkNodePath(proof, _key, _root);
+        TrieNode[] memory proof = _parseProof(_proof);
+        (uint256 pathLength, bytes memory keyRemainder, bool isFinalNode) = _walkNodePath(proof, _key, _root);
 
         if (_inclusion) {
             // Included leaf nodes should have no key remainder, values should match.
             return (
                 keyRemainder.length == 0 &&
-                Lib_ByteUtils.equal(getNodeValue(proof[pathLength - 1]), _value)
+                Lib_ByteUtils.equal(_getNodeValue(proof[pathLength - 1]), _value)
             );
         } else {
             // If there's no key remainder then a leaf with the given key exists and the value should differ.
             // Otherwise, we need to make sure that we've hit a dead end.
             return (
-                (keyRemainder.length == 0 && !Lib_ByteUtils.equal(getNodeValue(proof[pathLength - 1]), _value)) ||
+                (keyRemainder.length == 0 && !Lib_ByteUtils.equal(_getNodeValue(proof[pathLength - 1]), _value)) ||
                 (keyRemainder.length != 0 && isFinalNode)
             );
         }
@@ -257,7 +257,7 @@ library Lib_MerkleTrie {
      *     Whether or not we've hit a dead end;
      * )
      */
-    function walkNodePath(
+    function _walkNodePath(
         TrieNode[] memory _proof,
         bytes memory _key,
         bytes32 _root
@@ -316,17 +316,17 @@ library Lib_MerkleTrie {
                     // Figure out what the next node ID should be and continue.
                     uint8 branchKey = uint8(key[currentKeyIndex]);
                     Lib_RLPReader.RLPItem memory nextNode = currentNode.decoded[branchKey];
-                    currentNodeID = getNodeID(nextNode);
+                    currentNodeID = _getNodeID(nextNode);
                     currentKeyIncrement = 1;
                     continue;
                 }
             } else if (currentNode.decoded.length == LEAF_OR_EXTENSION_NODE_LENGTH) {
-                bytes memory path = getNodePath(currentNode);
+                bytes memory path = _getNodePath(currentNode);
                 uint8 prefix = uint8(path[0]);
                 uint8 offset = 2 - prefix % 2;
                 bytes memory pathRemainder = Lib_ByteUtils.slice(path, offset);
                 bytes memory keyRemainder = Lib_ByteUtils.slice(key, currentKeyIndex);
-                uint256 sharedNibbleLength = getSharedNibbleLength(pathRemainder, keyRemainder);
+                uint256 sharedNibbleLength = _getSharedNibbleLength(pathRemainder, keyRemainder);
 
                 if (prefix == PREFIX_LEAF_EVEN || prefix == PREFIX_LEAF_ODD) {
                     if (
@@ -350,7 +350,7 @@ library Lib_MerkleTrie {
                     } else {
                         // Our extension shares some nibbles.
                         // Carry on to the next node.
-                        currentNodeID = getNodeID(currentNode.decoded[1]);
+                        currentNodeID = _getNodeID(currentNode.decoded[1]);
                         currentKeyIncrement = sharedNibbleLength;
                         continue;
                     }
@@ -375,7 +375,7 @@ library Lib_MerkleTrie {
      * @param _value Value to insert at the given key.
      * @return A new path with the inserted k/v pair and extra supporting nodes.
      */
-    function getNewPath(
+    function _getNewPath(
         TrieNode[] memory _path,
         uint256 _pathLength,
         bytes memory _keyRemainder,
@@ -391,7 +391,7 @@ library Lib_MerkleTrie {
 
         // Most of our logic depends on the status of the last node in the path.
         TrieNode memory lastNode = _path[_pathLength - 1];
-        NodeType lastNodeType = getNodeType(lastNode);
+        NodeType lastNodeType = _getNodeType(lastNode);
 
         // Create an array for newly created nodes.
         // We need up to three new nodes, depending on the contents of the last node.
@@ -403,13 +403,13 @@ library Lib_MerkleTrie {
         if (keyRemainder.length == 0 && lastNodeType == NodeType.LeafNode) {
             // We've found a leaf node with the given key.
             // Simply need to update the value of the node to match.
-            newNodes[totalNewNodes] = makeLeafNode(getNodeKey(lastNode), _value);
+            newNodes[totalNewNodes] = _makeLeafNode(_getNodeKey(lastNode), _value);
             totalNewNodes += 1;
         } else if (lastNodeType == NodeType.BranchNode) {
             if (keyRemainder.length == 0) {
                 // We've found a branch node with the given key.
                 // Simply need to update the value of the node to match.
-                newNodes[totalNewNodes] = editBranchValue(lastNode, _value);
+                newNodes[totalNewNodes] = _editBranchValue(lastNode, _value);
                 totalNewNodes += 1;
             } else {
                 // We've found a branch node, but it doesn't contain our key.
@@ -418,19 +418,19 @@ library Lib_MerkleTrie {
                 totalNewNodes += 1;
                 // Create a new leaf node, slicing our remainder since the first byte points
                 // to our branch node.
-                newNodes[totalNewNodes] = makeLeafNode(Lib_ByteUtils.slice(keyRemainder, 1), _value);
+                newNodes[totalNewNodes] = _makeLeafNode(Lib_ByteUtils.slice(keyRemainder, 1), _value);
                 totalNewNodes += 1;
             }
         } else {
             // Our last node is either an extension node or a leaf node with a different key.
-            bytes memory lastNodeKey = getNodeKey(lastNode);
-            uint256 sharedNibbleLength = getSharedNibbleLength(lastNodeKey, keyRemainder);
+            bytes memory lastNodeKey = _getNodeKey(lastNode);
+            uint256 sharedNibbleLength = _getSharedNibbleLength(lastNodeKey, keyRemainder);
 
             if (sharedNibbleLength != 0) {
                 // We've got some shared nibbles between the last node and our key remainder.
                 // We'll need to insert an extension node that covers these shared nibbles.
                 bytes memory nextNodeKey = Lib_ByteUtils.slice(lastNodeKey, 0, sharedNibbleLength);
-                newNodes[totalNewNodes] = makeExtensionNode(nextNodeKey, getNodeHash(_value));
+                newNodes[totalNewNodes] = _makeExtensionNode(nextNodeKey, _getNodeHash(_value));
                 totalNewNodes += 1;
 
                 // Cut down the keys since we've just covered these shared nibbles.
@@ -439,13 +439,13 @@ library Lib_MerkleTrie {
             }
 
             // Create an empty branch to fill in.
-            TrieNode memory newBranch = makeEmptyBranchNode();
+            TrieNode memory newBranch = _makeEmptyBranchNode();
 
             if (lastNodeKey.length == 0) {
                 // Key remainder was larger than the key for our last node.
                 // The value within our last node is therefore going to be shifted into
                 // a branch value slot.
-                newBranch = editBranchValue(newBranch, getNodeValue(lastNode));
+                newBranch = _editBranchValue(newBranch, _getNodeValue(lastNode));
             } else {
                 // Last node key was larger than the key remainder.
                 // We're going to modify some index of our branch.
@@ -456,25 +456,25 @@ library Lib_MerkleTrie {
                 if (lastNodeType == NodeType.LeafNode) {
                     // We're dealing with a leaf node.
                     // We'll modify the key and insert the old leaf node into the branch index.
-                    TrieNode memory modifiedLastNode = makeLeafNode(lastNodeKey, getNodeValue(lastNode));
-                    newBranch = editBranchIndex(newBranch, branchKey, getNodeHash(modifiedLastNode.encoded));
+                    TrieNode memory modifiedLastNode = _makeLeafNode(lastNodeKey, _getNodeValue(lastNode));
+                    newBranch = _editBranchIndex(newBranch, branchKey, _getNodeHash(modifiedLastNode.encoded));
                 } else if (lastNodeKey.length != 0) {
                     // We're dealing with a shrinking extension node.
                     // We need to modify the node to decrease the size of the key.
-                    TrieNode memory modifiedLastNode = makeExtensionNode(lastNodeKey, getNodeValue(lastNode));
-                    newBranch = editBranchIndex(newBranch, branchKey, getNodeHash(modifiedLastNode.encoded));
+                    TrieNode memory modifiedLastNode = _makeExtensionNode(lastNodeKey, _getNodeValue(lastNode));
+                    newBranch = _editBranchIndex(newBranch, branchKey, _getNodeHash(modifiedLastNode.encoded));
                 } else {
                     // We're dealing with an unnecessary extension node.
                     // We're going to delete the node entirely.
                     // Simply insert its current value into the branch index.
-                    newBranch = editBranchIndex(newBranch, branchKey, getNodeValue(lastNode));
+                    newBranch = _editBranchIndex(newBranch, branchKey, _getNodeValue(lastNode));
                 }
             }
 
             if (keyRemainder.length == 0) {
                 // We've got nothing left in the key remainder.
                 // Simply insert the value into the branch value slot.
-                newBranch = editBranchValue(newBranch, _value);
+                newBranch = _editBranchValue(newBranch, _value);
                 // Push the branch into the list of new nodes.
                 newNodes[totalNewNodes] = newBranch;
                 totalNewNodes += 1;
@@ -487,14 +487,14 @@ library Lib_MerkleTrie {
                 newNodes[totalNewNodes] = newBranch;
                 totalNewNodes += 1;
                 // Push a new leaf node for our k/v pair.
-                newNodes[totalNewNodes] = makeLeafNode(keyRemainder, _value);
+                newNodes[totalNewNodes] = _makeLeafNode(keyRemainder, _value);
                 totalNewNodes += 1;
             }
         }
 
         // Finally, join the old path with our newly created nodes.
         // Since we're overwriting the last node in the path, we use `_pathLength - 1`.
-        return joinNodeArrays(_path, _pathLength - 1, newNodes, totalNewNodes);
+        return _joinNodeArrays(_path, _pathLength - 1, newNodes, totalNewNodes);
     }
 
     /**
@@ -503,7 +503,7 @@ library Lib_MerkleTrie {
      * @param _key Key for the k/v pair.
      * @return Root hash for the updated trie.
      */
-    function getUpdatedTrieRoot(
+    function _getUpdatedTrieRoot(
         TrieNode[] memory _nodes,
         bytes memory _key
     )
@@ -524,23 +524,23 @@ library Lib_MerkleTrie {
         for (uint256 i = _nodes.length; i > 0; i--) {
             // Pick out the current node.
             currentNode = _nodes[i - 1];
-            currentNodeType = getNodeType(currentNode);
+            currentNodeType = _getNodeType(currentNode);
 
             if (currentNodeType == NodeType.LeafNode) {
                 // Leaf nodes are already correctly encoded.
                 // Shift the key over to account for the nodes key.
-                bytes memory nodeKey = getNodeKey(currentNode);
+                bytes memory nodeKey = _getNodeKey(currentNode);
                 key = Lib_ByteUtils.slice(key, 0, key.length - nodeKey.length);
             } else if (currentNodeType == NodeType.ExtensionNode) {
                 // Shift the key over to account for the nodes key.
-                bytes memory nodeKey = getNodeKey(currentNode);
+                bytes memory nodeKey = _getNodeKey(currentNode);
                 key = Lib_ByteUtils.slice(key, 0, key.length - nodeKey.length);
 
                 // If this node is the last element in the path, it'll be correctly encoded
                 // and we can skip this part.
                 if (previousNodeHash.length > 0) {
                     // Re-encode the node based on the previous node.
-                    currentNode = makeExtensionNode(nodeKey, previousNodeHash);
+                    currentNode = _makeExtensionNode(nodeKey, previousNodeHash);
                 }
             } else if (currentNodeType == NodeType.BranchNode) {
                 // If this node is the last element in the path, it'll be correctly encoded
@@ -549,12 +549,12 @@ library Lib_MerkleTrie {
                     // Re-encode the node based on the previous node.
                     uint8 branchKey = uint8(key[key.length - 1]);
                     key = Lib_ByteUtils.slice(key, 0, key.length - 1);
-                    currentNode = editBranchIndex(currentNode, branchKey, previousNodeHash);
+                    currentNode = _editBranchIndex(currentNode, branchKey, previousNodeHash);
                 }
             }
 
             // Compute the node hash for the next iteration.
-            previousNodeHash = getNodeHash(currentNode.encoded);
+            previousNodeHash = _getNodeHash(currentNode.encoded);
         }
 
         // Current node should be the root at this point.
@@ -567,7 +567,7 @@ library Lib_MerkleTrie {
      * @param _proof RLP-encoded proof to parse.
      * @return Proof parsed into easily accessible structs.
      */
-    function parseProof(
+    function _parseProof(
         bytes memory _proof
     )
         private
@@ -597,7 +597,7 @@ library Lib_MerkleTrie {
      * @param _node Node to pull an ID for.
      * @return ID for the node, depending on the size of its contents.
      */
-    function getNodeID(
+    function _getNodeID(
         Lib_RLPReader.RLPItem memory _node
     )
         private
@@ -624,7 +624,7 @@ library Lib_MerkleTrie {
      * @param _node Node to get a path for.
      * @return Node path, converted to an array of nibbles.
      */
-    function getNodePath(
+    function _getNodePath(
         TrieNode memory _node
     )
         private
@@ -642,7 +642,7 @@ library Lib_MerkleTrie {
      * @param _node Node to get a key for.
      * @return Node key, converted to an array of nibbles.
      */
-    function getNodeKey(
+    function _getNodeKey(
         TrieNode memory _node
     )
         private
@@ -651,7 +651,7 @@ library Lib_MerkleTrie {
             bytes memory
         )
     {
-        return removeHexPrefix(getNodePath(_node));
+        return _removeHexPrefix(_getNodePath(_node));
     }
 
     /**
@@ -659,7 +659,7 @@ library Lib_MerkleTrie {
      * @param _node Node to get a value for.
      * @return Node value, as hex bytes.
      */
-    function getNodeValue(
+    function _getNodeValue(
         TrieNode memory _node
     )
         private
@@ -677,11 +677,11 @@ library Lib_MerkleTrie {
      * @param _encoded Encoded node to hash.
      * @return Hash of the encoded node. Simply the input if < 32 bytes.
      */
-    function getNodeHash(
+    function _getNodeHash(
         bytes memory _encoded
     )
         private
-        view
+        pure
         returns (
             bytes memory
         )
@@ -698,7 +698,7 @@ library Lib_MerkleTrie {
      * @param _node Node to determine a type for.
      * @return Type of the node; BranchNode/ExtensionNode/LeafNode.
      */
-    function getNodeType(
+    function _getNodeType(
         TrieNode memory _node
     )
         private
@@ -710,7 +710,7 @@ library Lib_MerkleTrie {
         if (_node.decoded.length == BRANCH_NODE_LENGTH) {
             return NodeType.BranchNode;
         } else if (_node.decoded.length == LEAF_OR_EXTENSION_NODE_LENGTH) {
-            bytes memory path = getNodePath(_node);
+            bytes memory path = _getNodePath(_node);
             uint8 prefix = uint8(path[0]);
 
             if (prefix == PREFIX_LEAF_EVEN || prefix == PREFIX_LEAF_ODD) {
@@ -730,7 +730,7 @@ library Lib_MerkleTrie {
      * @param _b Second nibble array.
      * @return Number of shared nibbles.
      */
-    function getSharedNibbleLength(
+    function _getSharedNibbleLength(
         bytes memory _a,
         bytes memory _b
     )
@@ -752,7 +752,7 @@ library Lib_MerkleTrie {
      * @param _raw RLP-encoded node to convert.
      * @return Node as a TrieNode struct.
      */
-    function makeNode(
+    function _makeNode(
         bytes[] memory _raw
     )
         private
@@ -774,7 +774,7 @@ library Lib_MerkleTrie {
      * @param _items RLP-decoded node to convert.
      * @return Node as a TrieNode struct.
      */
-    function makeNode(
+    function _makeNode(
         Lib_RLPReader.RLPItem[] memory _items
     )
         private
@@ -787,7 +787,7 @@ library Lib_MerkleTrie {
         for (uint256 i = 0; i < _items.length; i++) {
             raw[i] = Lib_RLPReader.toRlpBytes(_items[i]);
         }
-        return makeNode(raw);
+        return _makeNode(raw);
     }
 
     /**
@@ -796,7 +796,7 @@ library Lib_MerkleTrie {
      * @param _value Value for the extension node.
      * @return New extension node with the given k/v pair.
      */
-    function makeExtensionNode(
+    function _makeExtensionNode(
         bytes memory _key,
         bytes memory _value
     )
@@ -807,22 +807,22 @@ library Lib_MerkleTrie {
         )
     {
         bytes[] memory raw = new bytes[](2);
-        bytes memory key = addHexPrefix(_key, false);
+        bytes memory key = _addHexPrefix(_key, false);
         raw[0] = Lib_RLPWriter.encodeBytes(Lib_ByteUtils.fromNibbles(key));
         raw[1] = Lib_RLPWriter.encodeBytes(_value);
-        return makeNode(raw);
+        return _makeNode(raw);
     }
 
     /**
      * @notice Creates a new leaf node.
-     * @dev This function is essentially identical to `makeExtensionNode`.
+     * @dev This function is essentially identical to `_makeExtensionNode`.
      * Although we could route both to a single method with a flag, it's
      * more gas efficient to keep them separate and duplicate the logic.
      * @param _key Key for the leaf node, unprefixed.
      * @param _value Value for the leaf node.
      * @return New leaf node with the given k/v pair.
      */
-    function makeLeafNode(
+    function _makeLeafNode(
         bytes memory _key,
         bytes memory _value
     )
@@ -833,17 +833,17 @@ library Lib_MerkleTrie {
         )
     {
         bytes[] memory raw = new bytes[](2);
-        bytes memory key = addHexPrefix(_key, true);
+        bytes memory key = _addHexPrefix(_key, true);
         raw[0] = Lib_RLPWriter.encodeBytes(Lib_ByteUtils.fromNibbles(key));
         raw[1] = Lib_RLPWriter.encodeBytes(_value);
-        return makeNode(raw);
+        return _makeNode(raw);
     }
 
     /**
      * @notice Creates an empty branch node.
      * @return Empty branch node as a TrieNode stuct.
      */
-    function makeEmptyBranchNode()
+    function _makeEmptyBranchNode()
         private
         view
         returns (
@@ -854,7 +854,7 @@ library Lib_MerkleTrie {
         for (uint256 i = 0; i < raw.length; i++) {
             raw[i] = RLP_NULL_BYTES;
         }
-        return makeNode(raw);
+        return _makeNode(raw);
     }
 
     /**
@@ -863,7 +863,7 @@ library Lib_MerkleTrie {
      * @param _value Value to insert into the branch.
      * @return Modified branch node.
      */
-    function editBranchValue(
+    function _editBranchValue(
         TrieNode memory _branch,
         bytes memory _value
     )
@@ -875,7 +875,7 @@ library Lib_MerkleTrie {
     {
         bytes memory encoded = Lib_RLPWriter.encodeBytes(_value);
         _branch.decoded[_branch.decoded.length - 1] = Lib_RLPReader.toRlpItem(encoded);
-        return makeNode(_branch.decoded);
+        return _makeNode(_branch.decoded);
     }
 
     /**
@@ -885,7 +885,7 @@ library Lib_MerkleTrie {
      * @param _value Value to insert into the slot.
      * @return Modified branch node.
      */
-    function editBranchIndex(
+    function _editBranchIndex(
         TrieNode memory _branch,
         uint8 _index,
         bytes memory _value
@@ -898,7 +898,7 @@ library Lib_MerkleTrie {
     {
         bytes memory encoded = _value.length < 32 ? _value : Lib_RLPWriter.encodeBytes(_value);
         _branch.decoded[_index] = Lib_RLPReader.toRlpItem(encoded);
-        return makeNode(_branch.decoded);
+        return _makeNode(_branch.decoded);
     }
 
     /**
@@ -907,7 +907,7 @@ library Lib_MerkleTrie {
      * @param _isLeaf Whether or not the key belongs to a leaf.
      * @return Prefixed key.
      */
-    function addHexPrefix(
+    function _addHexPrefix(
         bytes memory _key,
         bool _isLeaf
     )
@@ -929,7 +929,7 @@ library Lib_MerkleTrie {
      * @param _path Path to remove the prefix from.
      * @return Unprefixed key.
      */
-    function removeHexPrefix(
+    function _removeHexPrefix(
         bytes memory _path
     )
         private
@@ -955,14 +955,14 @@ library Lib_MerkleTrie {
      * @param _bLength Length of the second array.
      * @return Combined node array.
      */
-    function joinNodeArrays(
+    function _joinNodeArrays(
         TrieNode[] memory _a,
         uint256 _aLength,
         TrieNode[] memory _b,
         uint256 _bLength
     )
         private
-        view
+        pure
         returns (
             TrieNode[] memory
         )
@@ -981,4 +981,4 @@ library Lib_MerkleTrie {
 
         return ret;
     }
-}
+}
\ No newline at end of file

packages/contracts/test/contracts/OVM/accounts/OVM_ECDSAContractAccount.spec.ts

+import { expect } from '../../../setup'
+
+describe('OVM_ECDSAContractAccount', () => {
+  describe('execute', () => {
+    describe('when provided an invalid signature', () => {
+      it('should revert', async () => {
+
+      })
+    })
+
+    describe('when provided a valid signature', () => {
+      describe('when provided an invalid nonce', () => {
+        it('should revert', async () => {
+
+        })
+      })
+
+      describe('when provided a valid nonce', () => {
+        describe('when executing ovmCREATE', () => {
+          it('should return the address of the created contract', async () => {
+
+          })
+        })
+
+        describe('when executing ovmCALL', () => {
+          it('should return the result of the call', async () => {
+
+          })
+        })
+      })
+    })
+  })
+})

packages/contracts/test/contracts/OVM/verification/OVM_StateTransitioner.spec.ts

+import { expect } from '../../../setup'
+
+describe('OVM_StateTransitioner', () => {
+  describe('proveContractState', () => {
+    describe('when provided an invalid code hash', () => {
+      it('should revert', async () => {
+          
+      })
+    })
+
+    describe('when provided a valid code hash', () => {
+      describe('when provided an invalid account inclusion proof', () => {
+        it('should revert', async () => {
+          
+        })
+      })
+
+      describe('when provided a valid account inclusion proof', () => {
+
+      })
+    })
+  })
+
+  describe('proveStorageSlot', () => {
+    describe('when the corresponding account is not proven', () => {
+      it('should revert', async () => {
+
+      })
+    })
+
+    describe('when the corresponding account is proven', () => {
+      describe('when provided an invalid slot inclusion proof', () => {
+        it('should revert', async () => {
+          
+        })
+      })
+
+      describe('when provided a valid slot inclusion proof', () => {
+
+      })
+    })
+  })
+
+  describe('applyTransaction', () => {
+    // TODO
+  })
+
+  describe('commitContractState', () => {
+    describe('when the account was not changed', () => {
+      it('should revert', async () => {
+
+      })
+    })
+
+    describe('when the account was changed', () => {
+      describe('when the account has not been committed', () => {
+        it('should commit the account and update the state', async () => {
+
+        })
+      })
+
+      describe('when the account was already committed', () => {
+        it('should revert', () => {
+
+        })
+      })
+    })
+  })
+
+  describe('commitStorageSlot', () => {
+    describe('when the slot was not changed', () => {
+      it('should revert', async () => {
+        
+      })
+    })
+
+    describe('when the slot was changed', () => {
+      describe('when the slot has not been committed', () => {
+        it('should commit the slot and update the state', async () => {
+
+        })
+      })
+
+      describe('when the slot was already committed', () => {
+        it('should revert', () => {
+
+        })
+      })
+    })
+  })
+
+  describe('completeTransition', () => {
+    describe('when there are uncommitted accounts', () => {
+      it('should revert', async () => {
+
+      })
+    })
+
+    describe('when there are uncommitted storage slots', () => {
+      it('should revert', async () => {
+
+      })
+    })
+
+    describe('when all state changes are committed', () => {
+
+    })
+  })
+})