Introduce a mock clock, use it to improve the getRecentTransactions unit tests. Fix a seconds/milliseconds confusion pointed out by Andreas. Resolves issue 43.

src/com/google/bitcoin/core/PeerAddress.java

@@ -71,7 +71,7 @@ public class PeerAddress extends Message {
     @Override
     public void bitcoinSerializeToStream(OutputStream stream) throws IOException {
         if (protocolVersion >= 31402) {
-            int secs = (int)(new Date().getTime() / 1000);
+            int secs = (int)(Utils.now().getTime() / 1000);
             uint32ToByteStreamLE(secs, stream);
         }
         uint64ToByteStreamLE(services, stream);  // nServices.

src/com/google/bitcoin/core/Transaction.java

@@ -149,7 +149,7 @@ public class Transaction extends Message implements Serializable {
      */
     void addBlockAppearance(StoredBlock block, boolean bestChain) {
         if (bestChain && updatedAt == null) {
-            updatedAt = new Date(block.getHeader().getTimeSeconds());
+            updatedAt = new Date(block.getHeader().getTimeSeconds() * 1000);
         }
         if (appearsIn == null) {
             appearsIn = new HashSet<StoredBlock>();
@@ -247,7 +247,7 @@ public class Transaction extends Message implements Serializable {
             for (StoredBlock b : appearsIn) {
                 earliestTimeSecs = Math.min(b.getHeader().getTimeSeconds(), earliestTimeSecs);
             }
-            updatedAt = new Date(earliestTimeSecs);
+            updatedAt = new Date(earliestTimeSecs * 1000);
         }
         return updatedAt;
     }

src/com/google/bitcoin/core/Utils.java

@@ -24,6 +24,7 @@ import java.math.BigDecimal;
 import java.math.BigInteger;
 import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;
+import java.util.Date;
 
 /**
  * A collection of various utility methods that are helpful for working with the BitCoin protocol.
@@ -238,4 +239,23 @@ public class Utils {
         if (size >= 3) bytes[6] = (byte) ((compact >>  0) & 0xFF);
         return decodeMPI(bytes);
     }
+
+    /** If non-null, overrides the return value of now(). */
+    public static Date mockTime;
+
+    /** Advances (or rewinds) the mock clock by the given number of seconds. */
+    public static Date rollMockClock(int seconds) {
+        if (mockTime == null)
+            mockTime = new Date();
+        mockTime = new Date(mockTime.getTime() + (seconds * 1000));
+        return mockTime;
+    }
+
+    /** Returns the current time, or a mocked out equivalent. */
+    public static Date now() {
+        if (mockTime != null)
+            return mockTime;
+        else
+            return new Date();
+    }
 }

src/com/google/bitcoin/core/Wallet.java

@@ -431,8 +431,7 @@ public class Wallet implements Serializable {
             connectedOutput.markAsSpent(input);
             maybeMoveTxToSpent(connectedTx, "spent tx");
         }
-        // Refresh the timestamp.
-        tx.updatedAt = new Date();
+        tx.updatedAt = Utils.now();
         // Add to the pending pool. It'll be moved out once we receive this transaction on the best chain.
         pending.put(tx.getHash(), tx);
     }

tests/com/google/bitcoin/core/TestUtils.java

@@ -65,7 +65,7 @@ public class TestUtils {
 
     public static BlockPair createFakeBlock(NetworkParameters params, BlockStore blockStore,
                                             Transaction... transactions) {
-        return createFakeBlock(params, blockStore, System.currentTimeMillis() / 1000, transactions);
+        return createFakeBlock(params, blockStore, Utils.now().getTime() / 1000, transactions);
     }
 
     public static Block makeSolvedTestBlock(NetworkParameters params,

tests/com/google/bitcoin/core/WalletTest.java

@@ -276,15 +276,15 @@ public class WalletTest {
     @Test
     public void transactionsList() throws Exception {
         // Check the wallet can give us an ordered list of all received transactions.
-        long time = System.currentTimeMillis() / 1000;
+        Utils.rollMockClock(0);
         // Receive a coin.
         Transaction tx1 = createFakeTx(params, Utils.toNanoCoins(1, 0), myAddress);
-        StoredBlock b1 = createFakeBlock(params, blockStore, time, tx1).storedBlock;
+        StoredBlock b1 = createFakeBlock(params, blockStore, tx1).storedBlock;
         wallet.receive(tx1, b1, BlockChain.NewBlockType.BEST_CHAIN);
         // Receive half a coin 10 minutes later.
-        time += 60 * 10;
+        Utils.rollMockClock(60 * 10);
         Transaction tx2 = createFakeTx(params, Utils.toNanoCoins(0, 5), myAddress);
-        StoredBlock b2 = createFakeBlock(params, blockStore, time, tx1).storedBlock;
+        StoredBlock b2 = createFakeBlock(params, blockStore, tx1).storedBlock;
         wallet.receive(tx2, b2, BlockChain.NewBlockType.BEST_CHAIN);
         // Check we got them back in order.
         List<Transaction> transactions = wallet.getTransactionsByTime();
@@ -296,7 +296,8 @@ public class WalletTest {
         assertEquals(1, transactions.size());
         assertEquals(tx2,  transactions.get(0));
 
-        // Create a spend.
+        // Create a spend five minutes later.
+        Utils.rollMockClock(60 * 5);
         Transaction tx3 = wallet.createSend(new ECKey().toAddress(params), Utils.toNanoCoins(0, 5));
         // Does not appear in list yet.
         assertEquals(2, wallet.getTransactionsByTime().size());