[#452] morph/client: Add reputation contract client

Signed-off-by: Alex Vanin <alexey@nspcc.ru>

pkg/morph/client/reputation/list.go

@@ -0,0 +1,62 @@
+package reputation
+
+import (
+	"github.com/nspcc-dev/neofs-node/pkg/morph/client"
+	"github.com/pkg/errors"
+)
+
+// ListByEpochArgs groups the arguments of
+// "list reputation ids by epoch" test invoke call.
+type ListByEpochArgs struct {
+	epoch uint64
+}
+
+// ListByEpochResult groups the stack parameters
+// returned by "list reputation ids by epoch" test invoke.
+type ListByEpochResult struct {
+	ids [][]byte
+}
+
+// SetEpoch sets epoch of expected reputation ids.
+func (l *ListByEpochArgs) SetEpoch(v uint64) {
+	l.epoch = v
+}
+
+// IDs returns slice of reputation id values.
+func (l ListByEpochResult) IDs() [][]byte {
+	return l.ids
+}
+
+// ListByEpoch invokes the call of "list reputation ids by epoch" method of
+// reputation contract.
+func (c *Client) ListByEpoch(args ListByEpochArgs) (*ListByEpochResult, error) {
+	prms, err := c.client.TestInvoke(
+		c.listByEpochMethod,
+		int64(args.epoch),
+	)
+	if err != nil {
+		return nil, errors.Wrapf(err, "could not perform test invocation (%s)", c.listByEpochMethod)
+	} else if ln := len(prms); ln != 1 {
+		return nil, errors.Errorf("unexpected stack item count (%s): %d", c.listByEpochMethod, ln)
+	}
+
+	items, err := client.ArrayFromStackItem(prms[0])
+	if err != nil {
+		return nil, errors.Wrapf(err, "could not get stack item array from stack item (%s)", c.listByEpochMethod)
+	}
+
+	res := &ListByEpochResult{
+		ids: make([][]byte, 0, len(items)),
+	}
+
+	for i := range items {
+		rawReputation, err := client.BytesFromStackItem(items[i])
+		if err != nil {
+			return nil, errors.Wrapf(err, "could not get byte array from stack item (%s)", c.listByEpochMethod)
+		}
+
+		res.ids = append(res.ids, rawReputation)
+	}
+
+	return res, nil
+}