[#987] morph/event: Add RemoveNode event and its parser

Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>

go.mod

@@ -12,8 +12,8 @@ require (
 	github.com/multiformats/go-multiaddr v0.4.0
 	github.com/nspcc-dev/hrw v1.0.9
 	github.com/nspcc-dev/neo-go v0.97.4-pre.0.20211123163659-b25c3775e847
-	github.com/nspcc-dev/neofs-api-go/v2 v2.11.0-pre.0.20211118144033-580f6c5554ff
-	github.com/nspcc-dev/neofs-sdk-go v0.0.0-20211123100340-d9317cbea191
+	github.com/nspcc-dev/neofs-api-go/v2 v2.11.0-pre.0.20211124141318-d93828f46514
+	github.com/nspcc-dev/neofs-sdk-go v0.0.0-20211126123811-1dde267424aa
 	github.com/nspcc-dev/tzhash v1.4.0
 	github.com/panjf2000/ants/v2 v2.4.0
 	github.com/paulmach/orb v0.2.2

pkg/morph/event/subnet/remove_node.go

@@ -0,0 +1,69 @@
+package subnet
+
+import (
+	"fmt"
+
+	"github.com/nspcc-dev/neo-go/pkg/rpc/response/result/subscriptions"
+	"github.com/nspcc-dev/neo-go/pkg/util"
+	"github.com/nspcc-dev/neofs-node/pkg/morph/client"
+	"github.com/nspcc-dev/neofs-node/pkg/morph/event"
+)
+
+// RemoveNode structure of subnet.RemoveNode notification from morph chain.
+type RemoveNode struct {
+	subnetID []byte
+	nodeKey  []byte
+
+	// txHash is used in notary environmental
+	// for calculating unique but same for
+	// all notification receivers values.
+	txHash util.Uint256
+}
+
+// MorphEvent implements Neo:Morph Event interface.
+func (RemoveNode) MorphEvent() {}
+
+// SubnetworkID returns a marshalled subnetID structure, defined in API.
+func (rn RemoveNode) SubnetworkID() []byte { return rn.subnetID }
+
+// Node is public key of the nodeKey that is being deleted.
+func (rn RemoveNode) Node() []byte { return rn.nodeKey }
+
+// TxHash returns hash of the TX with RemoveNode
+// notification.
+func (rn RemoveNode) TxHash() util.Uint256 { return rn.txHash }
+
+const expectedItemNumRemoveNode = 2
+
+// ParseRemoveNode parses notification into subnet event structure.
+//
+// Expects 2 stack items.
+func ParseRemoveNode(e *subscriptions.NotificationEvent) (event.Event, error) {
+	var (
+		ev  RemoveNode
+		err error
+	)
+
+	params, err := event.ParseStackArray(e)
+	if err != nil {
+		return nil, fmt.Errorf("could not parse stack items from notify event: %w", err)
+	}
+
+	if ln := len(params); ln != expectedItemNumRemoveNode {
+		return nil, event.WrongNumberOfParameters(expectedItemNumRemoveNode, ln)
+	}
+
+	ev.subnetID, err = client.BytesFromStackItem(params[0])
+	if err != nil {
+		return nil, fmt.Errorf("could not get raw subnetID: %w", err)
+	}
+
+	ev.nodeKey, err = client.BytesFromStackItem(params[1])
+	if err != nil {
+		return nil, fmt.Errorf("could not get raw public key of the node: %w", err)
+	}
+
+	ev.txHash = e.Container
+
+	return ev, nil
+}

pkg/morph/event/subnet/remove_node_test.go

@@ -0,0 +1,57 @@
+package subnet
+
+import (
+	"testing"
+
+	"github.com/nspcc-dev/neo-go/pkg/core/state"
+	"github.com/nspcc-dev/neo-go/pkg/crypto/keys"
+	"github.com/nspcc-dev/neo-go/pkg/rpc/response/result/subscriptions"
+	"github.com/nspcc-dev/neo-go/pkg/vm/stackitem"
+	subnetid "github.com/nspcc-dev/neofs-sdk-go/subnet/id"
+	"github.com/stretchr/testify/require"
+)
+
+func TestParseRemoveNode(t *testing.T) {
+	t.Run("wrong number of arguments", func(t *testing.T) {
+		_, err := ParseRemoveNode(createNotifyEventFromItems([]stackitem.Item{}))
+		require.Error(t, err)
+	})
+
+	t.Run("invalid item type", func(t *testing.T) {
+		args := []stackitem.Item{stackitem.NewMap(), stackitem.Make(123)}
+		_, err := ParseRemoveNode(createNotifyEventFromItems(args))
+		require.Error(t, err)
+	})
+
+	subnetID := subnetid.ID{}
+	subnetID.SetNumber(123)
+
+	rawSubnetID, err := subnetID.Marshal()
+	require.NoError(t, err)
+
+	priv, err := keys.NewPrivateKey()
+	require.NoError(t, err)
+
+	pub := priv.PublicKey()
+
+	t.Run("good", func(t *testing.T) {
+		args := []stackitem.Item{stackitem.NewByteArray(rawSubnetID), stackitem.Make(pub.Bytes())}
+
+		e, err := ParseRemoveNode(createNotifyEventFromItems(args))
+		require.NoError(t, err)
+
+		gotRaw := e.(RemoveNode).SubnetworkID()
+		require.NoError(t, err)
+
+		require.Equal(t, rawSubnetID, gotRaw)
+		require.Equal(t, pub.Bytes(), e.(RemoveNode).Node())
+	})
+}
+
+func createNotifyEventFromItems(items []stackitem.Item) *subscriptions.NotificationEvent {
+	return &subscriptions.NotificationEvent{
+		NotificationEvent: state.NotificationEvent{
+			Item: stackitem.NewArray(items),
+		},
+	}
+}