Small comments improvements.

README.md

@@ -207,7 +207,7 @@ A transaction contains a list of inputs and outputs representing a transfer of c
 
 ##### Operator
 
-The operator handles wallet and addresses as well the transaction creation. Most of its operation are CRUD related.
+The operator handles wallet and addresses as well the transaction creation. Most of its operation are CRUD related. Each node has its list of wallets and addresses, meaning that they aren't synchronized between nodes.
 
 ###### Wallet structure
 

lib/blockchain/block.js

@@ -30,7 +30,7 @@ class Block {
     }
 
     getDifficulty() {
-        // 14 is the maximum precision lenght supported by javascript
+        // 14 is the maximum precision length supported by javascript
         return parseInt(this.hash.substring(0, 14), 16);
     }
 

lib/blockchain/index.js

@@ -25,7 +25,7 @@ class Blockchain {
         this.blocksDb = new Db('data/' + dbName + '/' + BLOCKCHAIN_FILE, new Blocks());
         this.transactionsDb = new Db('data/' + dbName + '/' + TRANSACTIONS_FILE, new Transactions());
 
-        // INFO: In this implementation the database is a file so every time data is saved it rewrites the file, probably it should be a more robust database for performance reasons
+        // INFO: In this implementation the database is a file and every time data is saved it rewrites the file, probably it should be a more robust database for performance reasons
         this.blocks = this.blocksDb.read(Blocks);
         this.transactions = this.transactionsDb.read(Transactions);
 
@@ -42,7 +42,7 @@ class Blockchain {
             this.blocksDb.write(this.blocks);
         }
 
-        // Remove transactions that are in the chainblock
+        // Remove transactions that are in the blockchain
         console.info('Removing transactions that are in the blockchain');
         R.forEach(this.removeBlockTransactionsFromTransactions.bind(this), this.blocks);
     }
@@ -52,11 +52,11 @@ class Blockchain {
     }
 
     getBlockByIndex(index) {
-        return R.find((block) => { return block.index == index; }, this.blocks);
+        return R.find(R.propEq('index', index), this.blocks);
     }
 
     getBlockByHash(hash) {
-        return R.find((block) => { return block.hash == hash; }, this.blocks);
+        return R.find(R.propEq('hash', hash), this.blocks);
     }
 
     getLastBlock() {
@@ -81,15 +81,15 @@ class Blockchain {
     }
 
     getTransactionById(id) {
-        return R.find((transaction) => { return transaction.id == id; }, this.transactions);
+        return R.find(R.propEq('id', id), this.transactions);
     }
 
     getTransactionFromBlocks(transactionId) {
         return R.find(R.compose(R.find(R.propEq('id', transactionId)), R.prop('transactions')), this.blocks);
     }
 
     replaceChain(newBlockchain) {
-        // Doesn't make sense to replace this blockchain by a smaller one
+        // It doesn't make sense to replace this blockchain by a smaller one
         if (newBlockchain.length <= this.blocks.length) {
             console.error('Blockchain shorter than the current blockchain');
             throw new BlockchainAssertionError('Blockchain shorter than the current blockchain');
@@ -117,7 +117,7 @@ class Blockchain {
             throw new BlockchainAssertionError('Genesis block aren\'t the same');
         }
 
-        // Compare every block to the previous one (it skip the first one, because it was verified before)
+        // Compare every block to the previous one (it skips the first one, because it was verified before)
         try {
             for (let i = 1; i < blockchainToValidate.length; i++) {
                 this.checkBlock(blockchainToValidate[i], blockchainToValidate[i - 1]);
@@ -196,7 +196,7 @@ class Blockchain {
             throw new BlockAssertionError(`Invalid block balance: inputs sum '${sumOfInputsAmount}', outputs sum '${sumOfOutputsAmount}'`, { sumOfInputsAmount, sumOfOutputsAmount });
         }
 
-        // Check if there is only 1 type of fee transaction and 1 type of reward transaction;
+        // Check if there is only 1 fee transaction and 1 reward transaction;
         let transactionsByType = R.countBy(R.prop('type'), newBlock.transactions);
         if (transactionsByType.fee && transactionsByType.fee > 1) {
             console.error(`Invalid fee transaction count: expected '1' got '${transactionsByType.fee}'`);

lib/miner/index.js

@@ -42,7 +42,8 @@ class Miner {
         // Get the first two avaliable transactions, if there aren't 2, it's empty
         let transactions = R.defaultTo([], R.take(2, blockchainTransactions));
 
-        // Add fee transaction (1 satoshi per transaction), usually it is a fee over transaction size (not amount)
+        // Add fee transaction (1 satoshi per transaction)
+        // INFO: usually it's a fee over transaction size (not amount)
         if (transactions.length > 0) {
             let feeTransaction = Transaction.fromJson({
                 id: CryptoUtil.randomId(64),
@@ -53,7 +54,7 @@ class Miner {
                     outputs: [
                         {
                             amount: FEE_PER_TRANSACTION * transactions.length, // satoshis format
-                            address: address, // Usually here is a locking script (to check who and when this transaction output can be used), in this case it's simple the destination address 
+                            address: address, // INFO: Usually here is a locking script (to check who and when this transaction output can be used), in this case it's a simple destination address 
                         }
                     ]
                 }
@@ -73,7 +74,7 @@ class Miner {
                     outputs: [
                         {
                             amount: MINING_REWARD, // satoshis format
-                            address: address, // Usually here is a locking script (to check who and when this transaction output can be used), in this case it's simple the destination address 
+                            address: address, // INFO: Usually here is a locking script (to check who and when this transaction output can be used), in this case it's simple the destination address 
                         }
                     ]
                 }
@@ -96,7 +97,7 @@ class Miner {
         let start = process.hrtime();
         let block = Block.fromJson(jsonBlock);
 
-        // INFO: Every cryptocurrency as a different way to prove work, this is a simple hash sequence
+        // INFO: Every cryptocurrency has a different way to prove work, this is a simple hash sequence
 
         // Loop incrementing the nonce to find the hash at desired difficulty
         do {

lib/node/index.js

@@ -24,8 +24,8 @@ class Node {
             this.broadcast(this.sendTransaction, newTransaction);
         });
 
-        this.blockchain.emitter.on('blockchainReplaced', (block) => {
-            this.broadcast(this.sendLatestBlock, R.last(block));
+        this.blockchain.emitter.on('blockchainReplaced', (blocks) => {
+            this.broadcast(this.sendLatestBlock, R.last(blocks));
         });
     }
 
@@ -53,7 +53,7 @@ class Node {
     }
 
     initConnection(peer) {
-        // Initially it gets the latest block and all pending transactions
+        // It initially gets the latest block and all pending transactions
         this.getLatestBlock(peer);
         this.getTransactions(peer);
     }
@@ -150,7 +150,7 @@ class Node {
     }
 
     getConfirmations(transactionId) {
-        // Get in all peers if the transaction has been confirmed
+        // Get from all peers if the transaction has been confirmed
         let foundLocally = this.blockchain.getTransactionFromBlocks(transactionId) != null ? true : false;
         return Promise.all(R.map((peer) => {
             return this.getConfirmation(peer, transactionId);

lib/operator/index.js

@@ -12,7 +12,7 @@ class Operator {
     constructor(dbName, blockchain) {
         this.db = new Db('data/' + dbName + '/' + OPERATOR_FILE, new Wallets());
 
-        // INFO: In this implementation the database is a file so every time data is saved it rewrites the file, probably it should be a more robust database for performance reasons
+        // INFO: In this implementation the database is a file and every time data is saved it rewrites the file, probably it should be a more robust database for performance reasons
         this.wallets = this.db.read(Wallets);
         this.blockchain = blockchain;
     }

lib/operator/wallet.js

@@ -11,7 +11,7 @@ class Wallet {
     }
 
     generateAddress() {
-        // If secret is null it means is a brand new wallet
+        // If secret is null means it is a brand new wallet
         if (this.secret == null) {
             this.generateSecret();
         }

test/integrationTest.js

@@ -7,14 +7,13 @@ const Miner = require('../lib/miner');
 const Node = require('../lib/node');
 const fs = require('fs-extra');
 
+const name = 'integrationTest';
+require('../lib/util/consoleWrapper.js')(name, 0);
 
 describe('HTTP server', () => {
     it('should create wallet, address, mine, create transaction and mine again', () => {
-        const name = 'integrationTest';
-
-        fs.removeSync('data/' + name + '/');
-
-        require('../lib/util/consoleWrapper.js')(name, 0);
+
+        fs.removeSync('data/' + name + '/');      
 
         let blockchain = new Blockchain(name);
         let operator = new Operator(name, blockchain);