ethclient: add Version method to retrieve client version

ethclient/ethclient.go

@@ -77,6 +77,15 @@ func (ec *Client) ChainID(ctx context.Context) (*big.Int, error) {
 	return (*big.Int)(&result), err
 }
 
+// Version retrieves the current client version.
+func (ec *Client) Version(ctx context.Context) (string, error) {
+	var version string
+	if err := ec.c.CallContext(ctx, &version, "web3_clientVersion"); err != nil {
+		return "", err
+	}
+	return version, nil
+}
+
 // BlockByHash returns the given full block.
 //
 // Note that loading full blocks requires two requests. Use HeaderByHash

ethclient/ethclient_test.go

@@ -22,7 +22,10 @@ import (
 	"errors"
 	"fmt"
 	"math/big"
+	"os"
+	"path/filepath"
 	"reflect"
+	"runtime"
 	"testing"
 	"time"
 
@@ -165,6 +168,9 @@ func TestEthClient(t *testing.T) {
 		"ChainID": {
 			func(t *testing.T) { testChainID(t, client) },
 		},
+		"Version": {
+			func(t *testing.T) { testVersion(t, client) },
+		},
 		"GetBlock": {
 			func(t *testing.T) { testGetBlock(t, client) },
 		},
@@ -320,6 +326,17 @@ func testChainID(t *testing.T, client *rpc.Client) {
 	}
 }
 
+func testVersion(t *testing.T, client *rpc.Client) {
+	ec := ethclient.NewClient(client)
+	v, err := ec.Version(context.Background())
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if v != fmt.Sprintf("%s/%s-%s/%s", filepath.Base(os.Args[0]), runtime.GOOS, runtime.GOARCH, runtime.Version()) {
+		t.Fatalf("Version returned wrong value: %s", v)
+	}
+}
+
 func testGetBlock(t *testing.T, client *rpc.Client) {
 	ec := ethclient.NewClient(client)