`postConstruct` isn't called on abstract base class

[viceice]

Is there an existing issue for this?

• I have searched the existing issues

Current behavior

I've method mark with postConstruct on a base class which doesn't get called

Steps to reproduce

@injectable()
export abstract class BaseService {
  @postConstruct()
  protected async [Symbol('_construct')](): Promise<void> {
    // never called
    console.log("construct");
    await Promise.resolve();
  }
}

@injectable()
@injectFromHierarchy()
class RealService extends BaseService {
 // some more code     
}

const c = new Container({autobind:true));

await c.getAsync(RealService); // should log `construct`

Expected behavior

it should call decorated method

Possible solution

No response

Package version

7.9.1

Node.js version

v22.19.0

In which operating systems have you tested?

• macOS
• Windows
• Linux

Stack trace

No response

Other

• @postConstruct not called in parent class #615

[viceice]

my workaround is to move the function to a separate singleton service.

[notaphplover]

Hey @viceice, the issue is caused due to the fact injectFromBase and injectFromHierarchy do not propagate postConstruct nor preDestroy decorators. Strictly speaking, this is not a bug since the library is working as intended, but I guess we could propagate this kind of metadata. There's a small issue though: we currently have a single preDestroy and a single postConstruct method. What should we do if multiple base classes (a grand parent and a parent class, for example) have postConstruct metadata? I guess we should probably allow multiple preDestroy / postConstruct methods. At least I don't see a compeling reason not to do so.

my workaround is to move the function to a separate singleton service.

You can manually decorate your class as docs suggests:

@injectable()
export abstract class BaseService {
  @postConstruct()
  protected async [Symbol('_construct')](): Promise<void> {
    // never called
    console.log("construct");
    await Promise.resolve();
  }
}

@injectable()
@injectFromHierarchy()
class RealService extends BaseService {
 // some more code     
}

decorate(postConstruct(), RealService, Symbol('_construct')); // Manually decorate postConstruct()

const c = new Container({autobind:true));

await c.getAsync(RealService); // should log `construct`

[viceice]

OK, it's not a bug but unexpected behavior 😁

support via injectFromHierarchy would be a nice to have. but i've now moved that functionally to a singleton class, which executes the code once, so it's much faster anyways.

https://github.com/containerbase/base/blob/26628071e10f84da39e4924262fae17a67b5dd0a/src/cli/services/v2-tool.service.ts#L21

btw: Symbol('_construct') === Symbol('_construct') => false so using an anonymous symbol is intentional as that method should not be called outside of inversify 😉

[notaphplover]

OK, it's not a bug but unexpected behavior 😁

Hahaha. No, really, injectFromBase was originally designed to give you guys a way to propagate inject related metadata. Does it make sense we update it to propagate preDestroy and postConstruct metadata? Absolutelly, but that's another topic 😛.

support via injectFromHierarchy would be a nice to have. but i've now moved that functionally to a singleton class, which executes the code once, so it's much faster anyways.

Absolutely, we should provide similar contracts when possible.

btw: Symbol('_construct') === Symbol('_construct') => false so using an anonymous symbol is intentional as that method should not be called outside of inversify 😉

Yeah, my bad 😅, you can stil find the way to decorate it using decorate though.

[notaphplover]

inversify@7.10.0 has been released! 🎉. I'll update docs and then proceed to close this issue.

[viceice]

Thank you, will probably use it soon 😁