added SetTimeout() method on Client

client.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 	"io/ioutil"
 	"net/http"
+	"time"
 
 	"github.com/utekaravinash/gopaapi5/api"
 )
@@ -70,6 +71,11 @@ func NewClient(accessKey, secretKey, associateTag string, locale api.Locale) (*C
 	return client, nil
 }
 
+// SetTimeout sets a time limit for the operations made by the Client.
+func (c *Client) SetTimeout(duration time.Duration) {
+	c.httpClient.Timeout = duration
+}
+
 // send sends a http request to Amazon Product Advertising service and returns response or error
 func (c *Client) send(req *request, v interface{}) error {
 

client_test.go

@@ -1,7 +1,12 @@
 package gopaapi5
 
 import (
+	"io/ioutil"
+	"net/http"
+	"os"
+	"strings"
 	"testing"
+	"time"
 
 	"github.com/utekaravinash/gopaapi5/api"
 )
@@ -59,3 +64,55 @@ func TestNewClient(t *testing.T) {
 		})
 	}
 }
+
+func TestSetTimeout(t *testing.T) {
+	params := api.GetItemsParams{
+		ItemIds: []string{"0892131349"},
+	}
+
+	client, _ := NewClient("accessKey", "secretKey", "associateTag", api.UnitedStates)
+	client.testing = true
+
+	h := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		time.Sleep(time.Nanosecond * 10)
+		file, err := os.Open("_response/get_items.json")
+		if err != nil {
+			t.Errorf("Cannot open _response/get_items.json")
+		}
+
+		jo, err := ioutil.ReadAll(file)
+		if err != nil {
+			t.Errorf("Cannot read _response/get_items.json")
+		}
+
+		w.Write(jo)
+	})
+
+	httpClient, teardown := testingHTTPClient(h)
+	defer teardown()
+
+	client.httpClient = httpClient
+
+	client.SetTimeout(time.Nanosecond * 1)
+	_, err1 := client.GetItems(&params)
+
+	client.SetTimeout(time.Hour * 1)
+	response, _ := client.GetItems(&params)
+
+	tests := []struct {
+		name     string
+		expected interface{}
+		actual   interface{}
+	}{
+		{"Request Timeout", true, strings.Contains(err1.Error(), "Client.Timeout exceeded while awaiting headers")},
+		{"Request Completed", 2, len(response.ItemsResult.Items)},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			if test.expected != test.actual {
+				t.Errorf("Expected: %v, Actual: %v", test.expected, test.actual)
+			}
+		})
+	}
+}