From c3e35722bad23e13366c1186fd073ba60450e9ec Mon Sep 17 00:00:00 2001
From: Nishant Totla <nishanttotla@gmail.com>
Date: Fri, 1 Apr 2016 00:07:56 -0700
Subject: [PATCH] Adding function to allow for updating client version

Signed-off-by: Nishant Totla <nishanttotla@gmail.com>
---
 client/client.go      |  6 ++++++
 client/client_test.go | 47 +++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 53 insertions(+)

diff --git a/client/client.go b/client/client.go
index 0716667b..f91d235b 100644
--- a/client/client.go
+++ b/client/client.go
@@ -114,6 +114,12 @@ func (cli *Client) ClientVersion() string {
 	return cli.version
 }
 
+// UpdateClientVersion updates the version string associated with this
+// instance of the Client.
+func (cli *Client) UpdateClientVersion(v string) {
+	cli.version = v
+}
+
 // ParseHost verifies that the given host strings is valid.
 func ParseHost(host string) (string, string, string, error) {
 	protoAddrParts := strings.SplitN(host, "://", 2)
diff --git a/client/client_test.go b/client/client_test.go
index a00b21b3..45698544 100644
--- a/client/client_test.go
+++ b/client/client_test.go
@@ -1,8 +1,16 @@
 package client
 
 import (
+	"bytes"
+	"encoding/json"
+	"io/ioutil"
+	"net/http"
 	"net/url"
+	"strings"
 	"testing"
+
+	"github.com/docker/engine-api/types"
+	"golang.org/x/net/context"
 )
 
 func TestGetAPIPath(t *testing.T) {
@@ -70,3 +78,42 @@ func TestParseHost(t *testing.T) {
 		}
 	}
 }
+
+func TestUpdateClientVersion(t *testing.T) {
+	client := &Client{
+		transport: newMockClient(nil, func(req *http.Request) (*http.Response, error) {
+			splitQuery := strings.Split(req.URL.Path, "/")
+			queryVersion := splitQuery[1]
+			b, err := json.Marshal(types.Version{
+				APIVersion: queryVersion,
+			})
+			if err != nil {
+				return nil, err
+			}
+			return &http.Response{
+				StatusCode: http.StatusOK,
+				Body:       ioutil.NopCloser(bytes.NewReader(b)),
+			}, nil
+		}),
+	}
+
+	cases := []struct {
+		v string
+	}{
+		{"1.20"},
+		{"v1.21"},
+		{"1.22"},
+		{"v1.22"},
+	}
+
+	for _, cs := range cases {
+		client.UpdateClientVersion(cs.v)
+		r, err := client.ServerVersion(context.Background())
+		if err != nil {
+			t.Fatal(err)
+		}
+		if strings.TrimPrefix(r.APIVersion, "v") != strings.TrimPrefix(cs.v, "v") {
+			t.Fatalf("Expected %s, got %s", cs.v, r.APIVersion)
+		}
+	}
+}