MM-12067: Add SetDefaultProfileImage to reset the user profile image to a generated one (#9449)

* MM-12067: Add SetDefaultProfileImage to reset the user profile image to a generated one

* Allow to get the default profile image for my user

* Allowing to reset the last update image date to 0

* PR reviews

app/user_test.go

@@ -14,6 +14,7 @@ import (
 	"time"
 
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 
 	"github.com/mattermost/mattermost-server/einterfaces"
 	"github.com/mattermost/mattermost-server/model"
@@ -115,6 +116,25 @@ func TestCreateProfileImage(t *testing.T) {
 	}
 }
 
+func TestSetDefaultProfileImage(t *testing.T) {
+	th := Setup().InitBasic()
+	defer th.TearDown()
+
+	err := th.App.SetDefaultProfileImage(&model.User{
+		Id:       model.NewId(),
+		Username: "notvaliduser",
+	})
+	require.Error(t, err)
+
+	user := th.BasicUser
+
+	err = th.App.SetDefaultProfileImage(user)
+	require.Nil(t, err)
+
+	user = getUserFromDB(th.App, user.Id, t)
+	assert.Equal(t, int64(0), user.LastPictureUpdate)
+}
+
 func TestUpdateUserToRestrictedDomain(t *testing.T) {
 	th := Setup()
 	defer th.TearDown()
@@ -249,12 +269,12 @@ func TestUpdateOAuthUserAttrs(t *testing.T) {
 }
 
 func getUserFromDB(a *App, id string, t *testing.T) *model.User {
-	if user, err := a.GetUser(id); err != nil {
+	user, err := a.GetUser(id)
+	if err != nil {
 		t.Fatal("user is not found", err)
 		return nil
-	} else {
-		return user
 	}
+	return user
 }
 
 func getGitlabUserPayload(gitlabUser oauthgitlab.GitLabUser, t *testing.T) []byte {
@@ -530,10 +550,10 @@ func TestRecordUserServiceTermsAction(t *testing.T) {
 	defer th.TearDown()
 
 	user := &model.User{
-		Email: strings.ToLower(model.NewId()) + "success+test@example.com",
-		Nickname: "Luke Skywalker", // trying to bring balance to the "Force", one test user at a time
-		Username: "luke" + model.NewId(),
-		Password: "passwd1",
+		Email:       strings.ToLower(model.NewId()) + "success+test@example.com",
+		Nickname:    "Luke Skywalker", // trying to bring balance to the "Force", one test user at a time
+		Username:    "luke" + model.NewId(),
+		Password:    "passwd1",
 		AuthService: "",
 	}
 	user, err := th.App.CreateUser(user)