chainntnfs: replace defer cleanup with t.Cleanup

Signed-off-by: Eng Zer Jun <engzerjun@gmail.com>

chainntnfs/test_utils.go

@@ -165,7 +165,7 @@ func CreateSpendTx(t *testing.T, prevOutPoint *wire.OutPoint,
 // NewMiner spawns testing harness backed by a btcd node that can serve as a
 // miner.
 func NewMiner(t *testing.T, extraArgs []string, createChain bool,
-	spendableOutputs uint32) (*rpctest.Harness, func()) {
+	spendableOutputs uint32) *rpctest.Harness {
 
 	t.Helper()
 
@@ -175,12 +175,15 @@ func NewMiner(t *testing.T, extraArgs []string, createChain bool,
 
 	node, err := rpctest.New(NetParams, nil, extraArgs, "")
 	require.NoError(t, err, "unable to create backend node")
+	t.Cleanup(func() {
+		require.NoError(t, node.TearDown())
+	})
+
 	if err := node.SetUp(createChain, spendableOutputs); err != nil {
-		node.TearDown()
 		t.Fatalf("unable to set up backend node: %v", err)
 	}
 
-	return node, func() { node.TearDown() }
+	return node
 }
 
 // NewBitcoindBackend spawns a new bitcoind node that connects to a miner at the
@@ -190,7 +193,7 @@ func NewMiner(t *testing.T, extraArgs []string, createChain bool,
 // used for block and tx notifications or if its ZMQ interface should be used.
 // A connection to the newly spawned bitcoind node is returned.
 func NewBitcoindBackend(t *testing.T, minerAddr string, txindex,
-	rpcpolling bool) (*chain.BitcoindConn, func()) {
+	rpcpolling bool) *chain.BitcoindConn {
 
 	t.Helper()
 
@@ -219,6 +222,10 @@ func NewBitcoindBackend(t *testing.T, minerAddr string, txindex,
 	if err := bitcoind.Start(); err != nil {
 		t.Fatalf("unable to start bitcoind: %v", err)
 	}
+	t.Cleanup(func() {
+		_ = bitcoind.Process.Kill()
+		_ = bitcoind.Wait()
+	})
 
 	// Wait for the bitcoind instance to start up.
 	host := fmt.Sprintf("127.0.0.1:%d", rpcPort)
@@ -257,21 +264,16 @@ func NewBitcoindBackend(t *testing.T, minerAddr string, txindex,
 		return conn.Start()
 	}, 10*time.Second)
 	if err != nil {
-		bitcoind.Process.Kill()
-		bitcoind.Wait()
 		t.Fatalf("unable to establish connection to bitcoind: %v", err)
 	}
+	t.Cleanup(conn.Stop)
 
-	return conn, func() {
-		conn.Stop()
-		bitcoind.Process.Kill()
-		bitcoind.Wait()
-	}
+	return conn
 }
 
 // NewNeutrinoBackend spawns a new neutrino node that connects to a miner at
 // the specified address.
-func NewNeutrinoBackend(t *testing.T, minerAddr string) (*neutrino.ChainService, func()) {
+func NewNeutrinoBackend(t *testing.T, minerAddr string) *neutrino.ChainService {
 	t.Helper()
 
 	spvDir := t.TempDir()
@@ -283,6 +285,9 @@ func NewNeutrinoBackend(t *testing.T, minerAddr string) (*neutrino.ChainService,
 	if err != nil {
 		t.Fatalf("unable to create walletdb: %v", err)
 	}
+	t.Cleanup(func() {
+		spvDatabase.Close()
+	})
 
 	// Create an instance of neutrino connected to the running btcd
 	// instance.
@@ -294,7 +299,6 @@ func NewNeutrinoBackend(t *testing.T, minerAddr string) (*neutrino.ChainService,
 	}
 	spvNode, err := neutrino.NewChainService(spvConfig)
 	if err != nil {
-		spvDatabase.Close()
 		t.Fatalf("unable to create neutrino: %v", err)
 	}
 
@@ -304,9 +308,9 @@ func NewNeutrinoBackend(t *testing.T, minerAddr string) (*neutrino.ChainService,
 	for !spvNode.IsCurrent() {
 		time.Sleep(time.Millisecond * 100)
 	}
-
-	return spvNode, func() {
+	t.Cleanup(func() {
 		spvNode.Stop()
-		spvDatabase.Close()
-	}
+	})
+
+	return spvNode
 }