Can I test queries in goroutine with sqlmock? - unit-testing

Question

I have this code in my application, I use goroutine because that queries are very slow. The code works correctly but I've been trying to test that function with sqlmock and that been having a lot of false positives and a lot of dificulties, what can I do to test those queries using sqlmock? (Obs: I've used postgres)
func(r repository) Queries(ctx context.Context) (*models.MyModel, error) {
var users int64
var services int64
var sells int64
queryReponses := make(chan *gorm.DB, 3)
go func(){
queryResponses <- r.db.Raw("SELECT COUNT(*) FROM deposits").Find(&users)
}()
go func(){
queryResponses <- r.db.Raw("SELECT COUNT(*) FROM services").Find(&users)
}()
go func(){
queryResponses <- r.db.Raw("SELECT COUNT(*) FROM sells").Find(&users)
}()
for i := 0; i < 3; i += 1 {
queryResponse := <-queryReponses
if queryResponse.Error != nil {
return &models.MyModel{}, fmt.Errorf(queryResponse.Error)
}
}
return &models.MyModel{
Users: users,
Services: services,
Sells: sells,
}
}

Answer 1

You modify the same value concurrently, run your tests with a -race detector flag to detect it
go func(){
queryResponses <- r.db.Raw("SELECT COUNT(*) FROM deposits").Find(&users)
}()
- go func(){
queryResponses <- r.db.Raw("SELECT COUNT(*) FROM services").Find(&users)
+ go func(){
queryResponses <- r.db.Raw("SELECT COUNT(*) FROM services").Find(&services)
}()
- go func(){
queryResponses <- r.db.Raw("SELECT COUNT(*) FROM sells").Find(&users)
}()
+ go func(){
queryResponses <- r.db.Raw("SELECT COUNT(*) FROM sells").Find(&sells)
}()
also for such a case the sync/errgroup is more convenient to use:
var g errgroup.Group
g.Go(func() error {
return r.db.Raw("SELECT COUNT(*) FROM deposits").Find(&users).Error
})
g.Go(func() error {
return r.db.Raw("SELECT COUNT(*) FROM services").Find(&services).Error
})
if err := g.Wait(); err == nil {
return &models.MyModel{}, fmt.Errorf(queryResponse.Error)
}