MM-11855 Add App.HTTPService to allow mocking of HTTP client (#9359)

* MM-11855 Add App.HTTPService to allow mocking of HTTP client

* Initialize HTTPService earlier

app/apptestlib.go

@@ -6,6 +6,8 @@ package app
 import (
 	"io"
 	"io/ioutil"
+	"net/http"
+	"net/http/httptest"
 	"os"
 	"path/filepath"
 	"time"
@@ -33,6 +35,8 @@ type TestHelper struct {
 
 	tempConfigPath string
 	tempWorkspace  string
+
+	MockedHTTPService *MockedHTTPService
 }
 
 type persistentTestStore struct {
@@ -163,6 +167,13 @@ func (me *TestHelper) InitSystemAdmin() *TestHelper {
 	return me
 }
 
+func (me *TestHelper) MockHTTPService(handler http.Handler) *TestHelper {
+	me.MockedHTTPService = MakeMockedHTTPService(handler)
+	me.App.HTTPService = me.MockedHTTPService
+
+	return me
+}
+
 func (me *TestHelper) MakeEmail() string {
 	return "success_" + model.NewId() + "@simulator.amazonses.com"
 }
@@ -503,3 +514,22 @@ func (me *FakeClusterInterface) sendClearRoleCacheMessage() {
 		Event: model.CLUSTER_EVENT_INVALIDATE_CACHE_FOR_ROLES,
 	})
 }
+
+type MockedHTTPService struct {
+	Server *httptest.Server
+}
+
+func MakeMockedHTTPService(handler http.Handler) *MockedHTTPService {
+	return &MockedHTTPService{
+		Server: httptest.NewServer(handler),
+	}
+}
+
+func (h *MockedHTTPService) MakeClient(trustURLs bool) *http.Client {
+	return h.Server.Client()
+}
+
+func (h *MockedHTTPService) Close() {
+	h.Server.CloseClientConnections()
+	h.Server.Close()
+}