Unable to resolve parameterless subclass

[harindaka]

Let's say I have a base class and a subclass as follows

class MyBaseClass {
    #collectionName;

    constructor(collectionName) {
        this.#collectionName = collectionName;
    }

    getCollection() {
        return this.#collection;
    }
}

class MySubClass extends MyBaseClass {
    constructor() {
        super("users");
    }
}

I use awilix.InjectionMode.CLASSIC. When I try to resolve and instance of MySubClass, I get a resolution error which basically says Could not resolve 'collectionName'. MySubClass does not need constructor parameters to be passed in order to be instantiated. What gives?

[jeffijoe]

That’s probably a bug. I think empty ctor is treated like no ctor which is not the same.

[harindaka]

I'll try to whip up a code snippet to reproduce this today. Could it possibly be related to #107? I'll also try an older version.

[jeffijoe]

Yes that was the change that introduced the behavior.

If changed, it prevents the use of super(...arguments) which might not be desired by others.

[harindaka]

Does this mean that this bug would not be fixed in the long run since it would break features introduced in #107 ?

[jeffijoe]

I don’t know which behavior would be preferred by the majority. In your case you can make it work by adding = undefined in the base ctor. Params with default initializers won’t throw resolution errors.

[harindaka]

I wouldn't change the behavior before the next major version. But i'd say go with the most intuitive way for anyone adopting this library anew. Do what majority of the DI frameworks out there in the typesafe world are doing unless its not possible due to the dynamic nature of js. I'd argue in that sense the most intuitive way would be to support the scenario above. Would love to hear opposing views. I wonder if its technically possible to support both ways and let consuming developers specify which method to use explicitly when setting up the composition root.

[jeffijoe]

I’m not a fan of adding more config bloat.

Hoping others will chime in here to get an idea. I personally don’t use base classes so I don’t have this problem.

[linusnorton]

I hit this issue today. I would prefer have it work out of the box as I don't use super(...arguments).

Is there a work around other than having a default value of undefined in the parent class? My current plan is to just use asValue(new Whatever())

[jeffijoe]

Yes you can register the params too, that will work

[bosconian-dynamics]

I'll add my voice to the proponents for supporting truncated sub-class ctor args out-of-the-box. I think the ability to more definitively and intuitively map ctor args from child to a parent-class is more valuable than the convenience of passing them all up positionally with a spread... In my work, I feel the situation which the former arrangement solves occurs far, far more frequently than those which the latter addresses - but I don't claim to have any measurable experience with DI.

[jeffijoe]

Yeah, I think it makes sense.

[udnes99]

Also hit this issue. Is there any update with regards to whether it is planned on being fixed?

[jeffijoe]

A fix is planned for v6, I just haven’t had the time.

[udnes99]

Awesome! Love Awilix btw <3!