feat(API): optional display name on users

test/user_test.go

@@ -44,6 +44,8 @@ type mockUserRepo struct {
 	resetPasswordCalls                    int
 	lastResetPasswordUserId               uint32
 	lastResetPasswordHash                 string
+	updateDisplayNameCalls                int
+	lastUpdateDisplayName                 string
 }
 
 func newMockUserRepo() *mockUserRepo {
@@ -210,6 +212,21 @@ func (m *mockUserRepo) ResetPassword(userId uint32, hashedPassword string) (user
 	return u, nil
 }
 
+func (m *mockUserRepo) UpdateDisplayName(userId uint32, displayName string) (user.User, error) {
+	m.updateDisplayNameCalls++
+	m.lastUpdateDisplayName = displayName
+	if err := m.fail.trigger("UpdateDisplayName"); err != nil {
+		return user.User{}, err
+	}
+	u, ok := m.users[userId]
+	if !ok {
+		return user.User{}, user.ErrUserNotFound
+	}
+	u.DisplayName = displayName
+	m.users[userId] = u
+	return u, nil
+}
+
 var _ user.Repository = &mockUserRepo{}
 
 func TestCreateUser(t *testing.T) {