Initialize persisted state root on startup (#249)

fixes #600

lib/blockchain_double.js

@@ -132,6 +132,7 @@ BlockchainDouble.prototype.initialize = function(accounts, callback) {
       // If we already have a block, then that means there's an existing chain.
       // Don't create a genesis block.
       if (block) {
+        self._latestStateRoot = block.header.stateRoot;
         self.emit("block", block);
         return callback();
       }
@@ -243,26 +244,14 @@ BlockchainDouble.prototype.putBlock = function(block, logs, receipts, callback)
     var requests = [
       self.database.blocks.push.bind(self.database.blocks, block),
       self.database.blockLogs.push.bind(self.database.blockLogs, logs),
-      self.database.blockHashes.set.bind(
-        self.database.blockHashes,
-        to.hex(block.hash()),
-        length
-      )
+      self.database.blockHashes.set.bind(self.database.blockHashes, to.hex(block.hash()), length)
     ];
 
     block.transactions.forEach(function(tx, index) {
       var txHash = to.txHash(tx);
       requests.push(
-        self.database.transactions.set.bind(
-          self.database.transactions,
-          txHash,
-          tx
-        ),
-        self.database.transactionReceipts.set.bind(
-          self.database.transactionReceipts,
-          txHash,
-          receipts[index]
-        )
+        self.database.transactions.set.bind(self.database.transactions, txHash, tx),
+        self.database.transactionReceipts.set.bind(self.database.transactionReceipts, txHash, receipts[index])
       );
     });
 
@@ -305,28 +294,15 @@ BlockchainDouble.prototype.popBlock = function(callback) {
         var txHash = to.txHash(tx);
 
         requests.push(
-          self.database.transactions.del.bind(
-            self.database.transactions,
-            txHash
-          ),
-          self.database.transactionReceipts.del.bind(
-            self.database.transactionReceipts,
-            txHash
-          )
+          self.database.transactions.del.bind(self.database.transactions, txHash),
+          self.database.transactionReceipts.del.bind(self.database.transactionReceipts, txHash)
         );
       });
 
       requests.push(
-        self.database.blockLogs.pop.bind(
-          self.database.blockLogs
-        ),
-        self.database.blockHashes.del.bind(
-          self.database.blockHashes,
-          blockHash
-        ),
-        self.database.blocks.pop.bind(
-          self.database.blocks
-        ) // Do this one last in case anything relies on it.
+        self.database.blockLogs.pop.bind(self.database.blockLogs),
+        self.database.blockHashes.del.bind(self.database.blockHashes, blockHash),
+        self.database.blocks.pop.bind(self.database.blocks) // Do this one last in case anything relies on it.
       );
 
       async.series(requests, function(err) {

test/simpleAccountPersistence.js

@@ -0,0 +1,127 @@
+const Web3 = require("web3");
+const Ganache = require("../index.js");
+const assert = require("assert");
+const pify = require("pify");
+const BN = require("bn.js");
+const temp = require("temp").track();
+
+describe("Persistence ", function() {
+  describe("simple value transfer transactions", function() {
+    const dbPath = temp.mkdirSync("ganache-core-tests-");
+    const mnemonic = "candy maple cake sugar pudding cream honey rich smooth crumble sweet treat";
+
+    // use these to validate state
+    let newProvider = null;
+    let web3 = null;
+
+    // initial state;
+    let expectedLatestBlock = null;
+    let expectedAccounts = null;
+    let expectedNonces = null;
+    let expectedBalances = null;
+
+    before("Set up initial persisted blockchain", async function() {
+      const initialProvider = Ganache.provider({
+        db_path: dbPath,
+        mnemonic
+      });
+
+      const initialWeb3 = new Web3(initialProvider);
+
+      expectedAccounts = await initialWeb3.eth.getAccounts();
+
+      // we send 1 ether to get some state on the chain
+      const receipt = await initialWeb3.eth.sendTransaction({
+        from: expectedAccounts[0],
+        to: expectedAccounts[1],
+        value: initialWeb3.utils.toWei("1", "ether")
+      });
+
+      assert.strictEqual(receipt.status, true);
+
+      expectedLatestBlock = await initialWeb3.eth.getBlock("latest", true);
+
+      expectedNonces = expectedAccounts.map(async(account) => initialWeb3.eth.getTransactionCount(account));
+
+      expectedBalances = expectedAccounts.map(async(account) => initialWeb3.eth.getBalance(account));
+
+      // clean up after ourselves to make sure we don't have any lingering background tasks
+      initialWeb3.setProvider(null);
+      await pify(initialProvider.close)();
+    });
+
+    before("Open new provider using state persisted by last chain", async function() {
+      newProvider = Ganache.provider({
+        db_path: dbPath,
+        mnemonic
+      });
+
+      web3 = new Web3(newProvider);
+    });
+
+    it("should have the same latestBlock", async function() {
+      const latestBlock = await web3.eth.getBlock("latest", true);
+      assert.deepStrictEqual(latestBlock, expectedLatestBlock);
+    });
+
+    it("should have the same accounts", async function() {
+      const accounts = await web3.eth.getAccounts();
+      assert.deepStrictEqual(accounts, expectedAccounts);
+    });
+
+    it("should have the same nonces for known accounts", async function() {
+      const nonces = expectedAccounts.map(async(account) => web3.eth.getTransactionCount(account));
+      assert.deepStrictEqual(nonces, expectedNonces);
+    });
+
+    it("should have the same balances for known accounts", async function() {
+      const balances = expectedAccounts.map(async(account) => web3.eth.getBalance(account));
+      assert.deepStrictEqual(balances, expectedBalances);
+    });
+
+    it("should have a lower balance for account 0 as compared to account 1", async function() {
+      const acct0Balance = await web3.eth.getBalance(expectedAccounts[0]);
+      const acct1Balance = await web3.eth.getBalance(expectedAccounts[1]);
+
+      assert(new BN(acct0Balance).lt(new BN(acct1Balance)));
+    });
+
+    it("should allow further simple value transactions with the same accounts", async function() {
+      const account0InitialBalance = new BN(await web3.eth.getBalance(expectedAccounts[0]));
+      const account1InitialBalance = new BN(await web3.eth.getBalance(expectedAccounts[1]));
+
+      // returns BN because we pass a BN
+      const value = web3.utils.toWei(new BN(1), "ether");
+
+      // first, send the transaction
+      const receipt = await web3.eth.sendTransaction({
+        from: expectedAccounts[0],
+        to: expectedAccounts[1],
+        value: web3.utils.toWei("1", "ether")
+      });
+
+      assert.strictEqual(receipt.status, true);
+
+      const txData = await web3.eth.getTransaction(receipt.transactionHash);
+      const gasPrice = new BN(txData.gasPrice);
+      const gasUsed = new BN(receipt.gasUsed);
+
+      const gasCost = gasUsed.mul(gasPrice);
+
+      const expectedAccount0FinalBalance = account0InitialBalance.sub(value).sub(gasCost);
+      const expectedAccount1FinalBalance = account1InitialBalance.add(value);
+
+      const account0FinalBalance = new BN(await web3.eth.getBalance(expectedAccounts[0]));
+      const account1FinalBalance = new BN(await web3.eth.getBalance(expectedAccounts[1]));
+
+      assert(
+        account0FinalBalance.eq(expectedAccount0FinalBalance),
+        "Account 0 final balance doesn't match expected final balance"
+      );
+      assert(
+        account1FinalBalance.eq(expectedAccount1FinalBalance),
+        "Account 1 final balance doesn't match expected final balance"
+      );
+    });
+  });
+});