feature/box: first box and box.info implementation

I implemented the box interface for tarantool with a small number of fields, which in the future can be supplemented

Author: Maksim Konovalov

box/box.go

@@ -0,0 +1,24 @@
+package box
+
+import (
+	"github.com/tarantool/go-tarantool/v2"
+)
+
+// Box defines an interface for interacting with a Tarantool instance.
+// It includes the Info method, which retrieves instance information.
+type Box interface {
+	Info() (Info, error) // Retrieves detailed information about the Tarantool instance.
+}
+
+// box is a concrete implementation of the Box interface.
+// It holds a connection to the Tarantool instance via the Doer interface.
+type box struct {
+	conn tarantool.Doer // Connection interface for interacting with Tarantool.
+}
+
+// By returns a new instance of the box structure, which implements the Box interface.
+func By(conn tarantool.Doer) Box {
+	return &box{
+		conn: conn, // Assigns the provided Tarantool connection.
+	}
+}

box/box_test.go

@@ -0,0 +1,27 @@
+package box_test
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+	"github.com/tarantool/go-tarantool/v2/box"
+)
+
+func TestBy(t *testing.T) {
+	// We expect a panic because we are passing a nil connection (nil Doer) to the By function.
+	// The library does not control this zone, and the nil connection would cause a runtime error
+	// when we attempt to call methods (like Info) on it. This test ensures that such an invalid state
+	// is correctly handled by causing a panic, as it's outside of the library's responsibility.
+	require.Panics(t, func() {
+		// Create a box instance with a nil connection. This should lead to a panic later.
+		b := box.By(nil)
+
+		// Ensure the box instance is not nil (which it shouldn't be), but this is not meaningful
+		// since we will panic when we call the Info method with the nil connection.
+		require.NotNil(t, b)
+
+		// Calling Info on a box with a nil connection will result in a panic, since the underlying
+		// connection (Doer) cannot perform the requested action (it's nil).
+		_, _ = b.Info()
+	})
+}

box/info.go

@@ -0,0 +1,40 @@
+package box
+
+import "github.com/tarantool/go-tarantool/v2"
+
+// ClusterInfo represents information about the cluster.
+// It contains the unique identifier (UUID) of the cluster.
+type ClusterInfo struct {
+	UUID string `msgpack:"uuid"`
+}
+
+// Info represents detailed information about the Tarantool instance.
+// It includes version, node ID, read-only status, process ID, cluster information, and more.
+type Info struct {
+	Version string      `msgpack:"version"` // The version of the Tarantool instance.
+	ID      *int        `msgpack:"id"`      // The node ID (nullable).
+	RO      bool        `msgpack:"ro"`      // Read-only status of the instance.
+	UUID    string      `msgpack:"uuid"`    // Unique identifier of the instance.
+	PID     int         `msgpack:"pid"`     // Process ID of the instance.
+	Status  string      `msgpack:"status"`  // Current status of the instance (e.g., running, unconfigured).
+	Lsn     uint64      `msgpack:"lsn"`     // Log sequence number of the instance.
+	Cluster ClusterInfo `msgpack:"cluster"` // Cluster information, including cluster UUID.
+}
+
+// Info retrieves the current information of the Tarantool instance.
+// It calls the "box.info" function and parses the result into the Info structure.
+func (b *box) Info() (Info, error) {
+	var info Info
+
+	// Call "box.info" to get instance information from Tarantool.
+	fut := b.conn.Do(tarantool.NewCallRequest("box.info"))
+
+	// Parse the result into the Info structure.
+	err := fut.GetTyped(&[]interface{}{&info})
+	if err != nil {
+		return Info{}, err
+	}
+
+	// Return the parsed info and any potential error.
+	return info, err
+}

box/tarantool_test.go

@@ -0,0 +1,73 @@
+package box_test
+
+import (
+	"context"
+	"log"
+	"os"
+	"testing"
+	"time"
+
+	"github.com/google/uuid"
+	"github.com/stretchr/testify/require"
+	"github.com/tarantool/go-tarantool/v2"
+	"github.com/tarantool/go-tarantool/v2/box"
+	"github.com/tarantool/go-tarantool/v2/test_helpers"
+)
+
+var server = "127.0.0.1:3013"
+var dialer = tarantool.NetDialer{
+	Address:  server,
+	User:     "test",
+	Password: "test",
+}
+
+func validateUUID(t *testing.T, u string) {
+	var err error
+
+	_, err = uuid.Parse(u)
+
+	require.NoError(t, err)
+}
+
+func TestBox_Info(t *testing.T) {
+	ctx := context.TODO()
+
+	conn, err := tarantool.Connect(ctx, dialer, tarantool.Opts{})
+	require.NoError(t, err)
+
+	info, err := box.By(conn).Info()
+	require.NoError(t, err)
+
+	// check all fields run correctly
+	validateUUID(t, info.UUID)
+	validateUUID(t, info.Cluster.UUID)
+
+	require.NotEmpty(t, info.Version)
+	// check that pid parsed correctly
+	require.NotEqual(t, info.PID, 0)
+
+}
+
+func runTestMain(m *testing.M) int {
+	instance, err := test_helpers.StartTarantool(test_helpers.StartOpts{
+		Dialer:       dialer,
+		InitScript:   "testdata/config-memtx.lua",
+		Listen:       server,
+		WaitStart:    100 * time.Millisecond,
+		ConnectRetry: 10,
+		RetryTimeout: 500 * time.Millisecond,
+	})
+	defer test_helpers.StopTarantoolWithCleanup(instance)
+
+	if err != nil {
+		log.Printf("Failed to prepare test Tarantool: %s", err)
+		return 1
+	}
+
+	return m.Run()
+}
+
+func TestMain(m *testing.M) {
+	code := runTestMain(m)
+	os.Exit(code)
+}