rpctest: Add GenerateAndSubmitBlockWithCustomCoinbaseOutputs

integration/rpctest/blockgen.go

@@ -88,7 +88,8 @@ func standardCoinbaseScript(nextBlockHeight int32, extraNonce uint64) ([]byte, e
 // createCoinbaseTx returns a coinbase transaction paying an appropriate
 // subsidy based on the passed block height to the provided address.
 func createCoinbaseTx(coinbaseScript []byte, nextBlockHeight int32,
-	addr btcutil.Address, net *chaincfg.Params) (*btcutil.Tx, error) {
+	addr btcutil.Address, mineTo []wire.TxOut,
+	net *chaincfg.Params) (*btcutil.Tx, error) {
 
 	// Create the script to pay to the provided payment address.
 	pkScript, err := txscript.PayToAddrScript(addr)
@@ -105,10 +106,16 @@ func createCoinbaseTx(coinbaseScript []byte, nextBlockHeight int32,
 		SignatureScript: coinbaseScript,
 		Sequence:        wire.MaxTxInSequenceNum,
 	})
-	tx.AddTxOut(&wire.TxOut{
-		Value:    blockchain.CalcBlockSubsidy(nextBlockHeight, net),
-		PkScript: pkScript,
-	})
+	if len(mineTo) == 0 {
+		tx.AddTxOut(&wire.TxOut{
+			Value:    blockchain.CalcBlockSubsidy(nextBlockHeight, net),
+			PkScript: pkScript,
+		})
+	} else {
+		for i := range mineTo {
+			tx.AddTxOut(&mineTo[i])
+		}
+	}
 	return btcutil.NewTx(tx), nil
 }
 
@@ -118,8 +125,8 @@ func createCoinbaseTx(coinbaseScript []byte, nextBlockHeight int32,
 // second is used. Passing nil for the previous block results in a block that
 // builds off of the genesis block for the specified chain.
 func CreateBlock(prevBlock *btcutil.Block, inclusionTxs []*btcutil.Tx,
-	blockVersion int32, blockTime time.Time,
-	miningAddr btcutil.Address, net *chaincfg.Params) (*btcutil.Block, error) {
+	blockVersion int32, blockTime time.Time, miningAddr btcutil.Address,
+	mineTo []wire.TxOut, net *chaincfg.Params) (*btcutil.Block, error) {
 
 	var (
 		prevHash      *chainhash.Hash
@@ -156,7 +163,7 @@ func CreateBlock(prevBlock *btcutil.Block, inclusionTxs []*btcutil.Tx,
 		return nil, err
 	}
 	coinbaseTx, err := createCoinbaseTx(coinbaseScript, blockHeight,
-		miningAddr, net)
+		miningAddr, mineTo, net)
 	if err != nil {
 		return nil, err
 	}

integration/rpctest/rpc_harness.go

@@ -406,6 +406,27 @@ func (h *Harness) P2PAddress() string {
 // This function is safe for concurrent access.
 func (h *Harness) GenerateAndSubmitBlock(txns []*btcutil.Tx, blockVersion int32,
 	blockTime time.Time) (*btcutil.Block, error) {
+	return h.GenerateAndSubmitBlockWithCustomCoinbaseOutputs(txns,
+		blockVersion, blockTime, []wire.TxOut{})
+}
+
+// GenerateAndSubmitBlockWithCustomCoinbaseOutputs creates a block whose
+// contents include the passed coinbase outputs and transactions and submits
+// it to the running simnet node. For generating blocks with only a coinbase tx,
+// callers can simply pass nil instead of transactions to be mined.
+// Additionally, a custom block version can be set by the caller. A blockVersion
+// of -1 indicates that the current default block version should be used. An
+// uninitialized time.Time should be used for the blockTime parameter if one
+// doesn't wish to set a custom time. The mineTo list of outputs will be added
+// to the coinbase; this is not checked for correctness until the block is
+// submitted; thus, it is the caller's responsibility to ensure that the outputs
+// are correct. If the list is empty, the coinbase reward goes to the wallet
+// managed by the Harness.
+//
+// This function is safe for concurrent access.
+func (h *Harness) GenerateAndSubmitBlockWithCustomCoinbaseOutputs(
+	txns []*btcutil.Tx, blockVersion int32, blockTime time.Time,
+	mineTo []wire.TxOut) (*btcutil.Block, error) {
 
 	h.Lock()
 	defer h.Unlock()
@@ -427,7 +448,7 @@ func (h *Harness) GenerateAndSubmitBlock(txns []*btcutil.Tx, blockVersion int32,
 
 	// Create a new block including the specified transactions
 	newBlock, err := CreateBlock(prevBlock, txns, blockVersion,
-		blockTime, h.wallet.coinbaseAddr, h.ActiveNet)
+		blockTime, h.wallet.coinbaseAddr, mineTo, h.ActiveNet)
 	if err != nil {
 		return nil, err
 	}

integration/rpctest/rpc_harness_test.go

@@ -391,6 +391,81 @@ func testGenerateAndSubmitBlock(r *Harness, t *testing.T) {
 	}
 }
 
+func testGenerateAndSubmitBlockWithCustomCoinbaseOutputs(r *Harness,
+	t *testing.T) {
+	// Generate a few test spend transactions.
+	addr, err := r.NewAddress()
+	if err != nil {
+		t.Fatalf("unable to generate new address: %v", err)
+	}
+	pkScript, err := txscript.PayToAddrScript(addr)
+	if err != nil {
+		t.Fatalf("unable to create script: %v", err)
+	}
+	output := wire.NewTxOut(btcutil.SatoshiPerBitcoin, pkScript)
+
+	const numTxns = 5
+	txns := make([]*btcutil.Tx, 0, numTxns)
+	for i := 0; i < numTxns; i++ {
+		tx, err := r.CreateTransaction([]*wire.TxOut{output}, 10)
+		if err != nil {
+			t.Fatalf("unable to create tx: %v", err)
+		}
+
+		txns = append(txns, btcutil.NewTx(tx))
+	}
+
+	// Now generate a block with the default block version, a zero'd out
+	// time, and a burn output.
+	block, err := r.GenerateAndSubmitBlockWithCustomCoinbaseOutputs(txns,
+		-1, time.Time{}, []wire.TxOut{{
+			Value:    0,
+			PkScript: []byte{},
+		}})
+	if err != nil {
+		t.Fatalf("unable to generate block: %v", err)
+	}
+
+	// Ensure that all created transactions were included, and that the
+	// block version was properly set to the default.
+	numBlocksTxns := len(block.Transactions())
+	if numBlocksTxns != numTxns+1 {
+		t.Fatalf("block did not include all transactions: "+
+			"expected %v, got %v", numTxns+1, numBlocksTxns)
+	}
+	blockVersion := block.MsgBlock().Header.Version
+	if blockVersion != BlockVersion {
+		t.Fatalf("block version is not default: expected %v, got %v",
+			BlockVersion, blockVersion)
+	}
+
+	// Next generate a block with a "non-standard" block version along with
+	// time stamp a minute after the previous block's timestamp.
+	timestamp := block.MsgBlock().Header.Timestamp.Add(time.Minute)
+	targetBlockVersion := int32(1337)
+	block, err = r.GenerateAndSubmitBlockWithCustomCoinbaseOutputs(nil,
+		targetBlockVersion, timestamp, []wire.TxOut{{
+			Value:    0,
+			PkScript: []byte{},
+		}})
+	if err != nil {
+		t.Fatalf("unable to generate block: %v", err)
+	}
+
+	// Finally ensure that the desired block version and timestamp were set
+	// properly.
+	header := block.MsgBlock().Header
+	blockVersion = header.Version
+	if blockVersion != targetBlockVersion {
+		t.Fatalf("block version mismatch: expected %v, got %v",
+			targetBlockVersion, blockVersion)
+	}
+	if !timestamp.Equal(header.Timestamp) {
+		t.Fatalf("header time stamp mismatch: expected %v, got %v",
+			timestamp, header.Timestamp)
+	}
+}
+
 func testMemWalletReorg(r *Harness, t *testing.T) {
 	// Create a fresh harness, we'll be using the main harness to force a
 	// re-org on this local harness.
@@ -478,6 +553,7 @@ var harnessTestCases = []HarnessTestCase{
 	testJoinBlocks,
 	testJoinMempools, // Depends on results of testJoinBlocks
 	testGenerateAndSubmitBlock,
+	testGenerateAndSubmitBlockWithCustomCoinbaseOutputs,
 	testMemWalletReorg,
 	testMemWalletLockedOutputs,
 }