Service register best practices about do HOT 5 CLOSED

Yes, declaring services globally might create import cycles sometimes.

In v2-beta6, we added support for "do.Package" -> https://do.samber.dev/docs/getting-started#register-services-using-package-declaration

You can create a do.Package in ***/biz/service/ for a subset of your app.

go get -u github.com/samber/do/[email protected]

If you currently use v1, check the migration guide: https://do.samber.dev/docs/upgrading/from-v1-x-to-v2

I currently use v2 in my own project. You can consider it almost production-ready. Some APIs might change before release.

from do.

Thx, I try to do.Package.
I used v2 in production for some time, it is very good.

from do.

Hello samber, do.Package doesn't seem to solve my problem.

Maybe I didn't describe it in detail enough. I create a demo: https://github.com/iyaozhen/samber-do-learn/blob/main/service/car/car_test.go

import cycle:

package github.com/iyaozhen/samber-do-learn/service/car
	imports github.com/iyaozhen/samber-do-learn/service
	imports github.com/iyaozhen/samber-do-learn/service/car: import cycle not allowed in test

TestCar_Start_V2 It is work, but I will add lots of do.Provide.

service/register.go, Should it not exist?

I should use do.Package in car? But engine used in a other car2 service, car and car2 Lazy/Provide Duplicate?

from do.

Ok, i see your issue.

Maybe you could move your tests to a dedicated package? 🤔

I don't know the complexity of your app, but you can also have a do.Package in 2 sub-packages (here: service/engine/ and service/car/) and import them in tests: do.New(engine.Pkg, car.Pkg).

I don't know if this issue is related to DI, since you would have the same problem in traditional programming.

Did you try with interfaces? Using do.InvokeAs might prevent some troubles.

from do.

Thank you for your patient answer. There's no particular solution for me.

move your tests to a dedicated package

not golang customary norm

2 sub-packages

car.Package

do.Package(
	do.Lazy(engine.NewEngine),
	do.Lazy(NewCar),
)

airplane.Package

do.Package(
	do.Lazy(engine.NewEngine),
	do.Lazy(NewAirplane),
)

https://github.com/iyaozhen/samber-do-learn/blob/main/service/car/car_test.go

panic: DI: service `*/service/engine.Engine` has already been declared

interface

interface is a good way. But it will make the project more complex. In general, there is only one implementation of an interface.

This is not do is problem, the same problem in traditional programming.

I'll close this issue first, If there is a good solution, I will come back to update.

from do.