[#44] version: move package from neofs-api-go

Also remove `Version` from constructors and rename `SDKVersion` to
`Current`.

Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>

version/version.go

@@ -0,0 +1,89 @@
+package version
+
+import (
+	"fmt"
+
+	"github.com/nspcc-dev/neofs-api-go/v2/refs"
+)
+
+// Version represents v2-compatible version.
+type Version refs.Version
+
+const sdkMjr, sdkMnr = 2, 10
+
+// NewFromV2 wraps v2 Version message to Version.
+//
+// Nil refs.Version converts to nil.
+func NewFromV2(v *refs.Version) *Version {
+	return (*Version)(v)
+}
+
+// New creates and initializes blank Version.
+//
+// Defaults:
+//  - major: 0;
+//  - minor: 0.
+func New() *Version {
+	return NewFromV2(new(refs.Version))
+}
+
+// Current returns Version instance that
+// initialized to current SDK revision number.
+func Current() *Version {
+	v := New()
+	v.SetMajor(sdkMjr)
+	v.SetMinor(sdkMnr)
+
+	return v
+}
+
+// Major returns major number of the revision.
+func (v *Version) Major() uint32 {
+	return (*refs.Version)(v).GetMajor()
+}
+
+// SetMajor sets major number of the revision.
+func (v *Version) SetMajor(val uint32) {
+	(*refs.Version)(v).SetMajor(val)
+}
+
+// Minor returns minor number of the revision.
+func (v *Version) Minor() uint32 {
+	return (*refs.Version)(v).GetMinor()
+}
+
+// SetMinor sets minor number of the revision.
+func (v *Version) SetMinor(val uint32) {
+	(*refs.Version)(v).SetMinor(val)
+}
+
+// ToV2 converts Version to v2 Version message.
+//
+// Nil Version converts to nil.
+func (v *Version) ToV2() *refs.Version {
+	return (*refs.Version)(v)
+}
+
+func (v *Version) String() string {
+	return fmt.Sprintf("v%d.%d", v.Major(), v.Minor())
+}
+
+// Marshal marshals Version into a protobuf binary form.
+func (v *Version) Marshal() ([]byte, error) {
+	return (*refs.Version)(v).StableMarshal(nil)
+}
+
+// Unmarshal unmarshals protobuf binary representation of Version.
+func (v *Version) Unmarshal(data []byte) error {
+	return (*refs.Version)(v).Unmarshal(data)
+}
+
+// MarshalJSON encodes Version to protobuf JSON format.
+func (v *Version) MarshalJSON() ([]byte, error) {
+	return (*refs.Version)(v).MarshalJSON()
+}
+
+// UnmarshalJSON decodes Version from protobuf JSON format.
+func (v *Version) UnmarshalJSON(data []byte) error {
+	return (*refs.Version)(v).UnmarshalJSON(data)
+}

version/version_test.go

@@ -0,0 +1,90 @@
+package version
+
+import (
+	"testing"
+
+	"github.com/nspcc-dev/neofs-api-go/v2/refs"
+	"github.com/stretchr/testify/require"
+)
+
+func TestNewVersion(t *testing.T) {
+	t.Run("default values", func(t *testing.T) {
+		v := New()
+
+		// check initial values
+		require.Zero(t, v.Major())
+		require.Zero(t, v.Minor())
+
+		// convert to v2 message
+		vV2 := v.ToV2()
+
+		require.Empty(t, vV2.GetMajor())
+		require.Empty(t, vV2.GetMinor())
+	})
+
+	t.Run("setting values", func(t *testing.T) {
+		v := New()
+
+		var mjr, mnr uint32 = 1, 2
+
+		v.SetMajor(mjr)
+		v.SetMinor(mnr)
+
+		require.Equal(t, mjr, v.Major())
+		require.Equal(t, mnr, v.Minor())
+
+		ver := v.ToV2()
+
+		require.Equal(t, mjr, ver.GetMajor())
+		require.Equal(t, mnr, ver.GetMinor())
+	})
+}
+
+func TestSDKVersion(t *testing.T) {
+	v := Current()
+
+	require.Equal(t, uint32(sdkMjr), v.Major())
+	require.Equal(t, uint32(sdkMnr), v.Minor())
+}
+
+func TestVersionEncoding(t *testing.T) {
+	v := New()
+	v.SetMajor(1)
+	v.SetMinor(2)
+
+	t.Run("binary", func(t *testing.T) {
+		data, err := v.Marshal()
+		require.NoError(t, err)
+
+		v2 := New()
+		require.NoError(t, v2.Unmarshal(data))
+
+		require.Equal(t, v, v2)
+	})
+
+	t.Run("json", func(t *testing.T) {
+		data, err := v.MarshalJSON()
+		require.NoError(t, err)
+
+		v2 := New()
+		require.NoError(t, v2.UnmarshalJSON(data))
+
+		require.Equal(t, v, v2)
+	})
+}
+
+func TestNewVersionFromV2(t *testing.T) {
+	t.Run("from nil", func(t *testing.T) {
+		var x *refs.Version
+
+		require.Nil(t, NewFromV2(x))
+	})
+}
+
+func TestVersion_ToV2(t *testing.T) {
+	t.Run("nil", func(t *testing.T) {
+		var x *Version
+
+		require.Nil(t, x.ToV2())
+	})
+}