Reward Transaction

config.js

@@ -12,4 +12,14 @@ const GENESIS_DATA = {
 
 const STARTING_BALANCE = 1000;
 
-module.exports = { GENESIS_DATA, MINE_RATE, STARTING_BALANCE };
+const REWARD_INPUT = { address: '*authorized-reward*' };
+
+const MINING_REWARD = 50;
+
+module.exports = {
+  GENESIS_DATA,
+  MINE_RATE,
+  STARTING_BALANCE,
+  REWARD_INPUT,
+  MINING_REWARD
+};

wallet/transaction.js

@@ -1,11 +1,12 @@
 const uuid = require('uuid/v1');
 const { verifySignature } = require('../util');
+const { REWARD_INPUT, MINING_REWARD } = require('../config');
 
 class Transaction {
-  constructor({ senderWallet, recipient, amount }) {
+  constructor({ senderWallet, recipient, amount, outputMap, input }) {
     this.id = uuid();
-    this.outputMap = this.createOutputMap({ senderWallet, recipient, amount });
-    this.input = this.createInput({ senderWallet, outputMap: this.outputMap });
+    this.outputMap = outputMap || this.createOutputMap({ senderWallet, recipient, amount });
+    this.input = input || this.createInput({ senderWallet, outputMap: this.outputMap });
   }
 
   createOutputMap({ senderWallet, recipient, amount }) {
@@ -62,6 +63,13 @@ class Transaction {
 
     return true;
   }
+
+  static rewardTransaction({ minerWallet }) {
+    return new this({
+      input: REWARD_INPUT,
+      outputMap: { [minerWallet.publicKey]: MINING_REWARD }
+    });
+  }
 }
 
 module.exports = Transaction;

wallet/transaction.test.js

@@ -1,6 +1,7 @@
 const Transaction = require('./transaction');
 const Wallet = require('./index');
 const { verifySignature } = require('../util');
+const { REWARD_INPUT, MINING_REWARD } = require('../config');
 
 describe('Transaction', () => {
   let transaction, senderWallet, recipient, amount;
@@ -163,5 +164,22 @@ describe('Transaction', () => {
       });
     });
   });
+
+  describe('rewardTransaction()', () => {
+    let rewardTransaction, minerWallet;
+
+    beforeEach(() => {
+      minerWallet = new Wallet();
+      rewardTransaction = Transaction.rewardTransaction({ minerWallet });
+    });
+
+    it('creates a transaction with the reward input', () => {
+      expect(rewardTransaction.input).toEqual(REWARD_INPUT);
+    });
+
+    it('creates one transaction for the miner with the `MINING_REWARD`', () => {
+      expect(rewardTransaction.outputMap[minerWallet.publicKey]).toEqual(MINING_REWARD);
+    });
+  });
 });