test: Use round tripper for mocking http client responses

Author: TwiN

client.go

@@ -5,21 +5,17 @@ import (
 	"time"
 )
 
-var client HttpClient
-
-type HttpClient interface {
-	Do(req *http.Request) (*http.Response, error)
-}
+var httpClient *http.Client
 
 // getHTTPClient returns the shared HTTP client
-func getHTTPClient() HttpClient {
-	if client == nil {
+func getHTTPClient() *http.Client {
+	if httpClient == nil {
 		tr := http.DefaultTransport.(*http.Transport).Clone()
 		tr.MaxIdleConnsPerHost = 50
-		client = &http.Client{
+		httpClient = &http.Client{
 			Timeout:   time.Second * 10,
 			Transport: tr,
 		}
 	}
-	return client
+	return httpClient
 }

client_test.go

@@ -7,20 +7,15 @@ import (
 )
 
 func TestValidateClient(t *testing.T) {
-	oldRef := getHTTPClient()
-	defer func() {
-		client = oldRef
-	}()
-	client = nil
+	httpClient = nil
 	client := getHTTPClient()
 	if client == nil {
 		t.Error("client should not be nil")
 	}
-	cl := client.(*http.Client)
-	if cl.Timeout != 10*time.Second {
+	if client.Timeout != 10*time.Second {
 		t.Error("default timeout should be 10 seconds")
 	}
-	tr := cl.Transport.(*http.Transport)
+	tr := client.Transport.(*http.Transport)
 	if tr.MaxIdleConnsPerHost != 50 {
 		t.Error("default max conns idle conns per host should be 150")
 	}