Consider generating interop for Dagger*Component shims

[ZacSweers]

Referenced in https://code.cash.app/cash-android-moves-to-metro. Wouldn't be possible until 2.3.20 at the soonest though

[inorichi]

I'm very interested in this. We have one component per feature (over 200 components), so the approach of CashApp isn't as simple for us, sadly.

Would you mind explaining the compiler limitation? I'd be willing to try to implement it, but if there's a blocker...

[ZacSweers]

#460 is the limitation

[consp1racy]

"Hint generation (i.e. multi-module aggregation) and top-level function injection only works on jvm/android targets" should be good enough for Dagger as it's JVM/Android-only, no?

[ZacSweers]

Read the latest comment

[inorichi]

From total ignorance, can the factories be generated or is that also not possible? I've written a simple KSP processor that generates the following code for component factories and it works fine:

package $pkg
                
import dev.zacsweers.metro.createGraphFactory

// Generated code
public object Dagger$component {
    public fun factory(): $component.$factory {
        return createGraphFactory<$component.$factory>()
    }
}

The code is pretty simple, so it makes me wonder if this small code is not possible to generate by the compiler plugin.

[ZacSweers]

I encourage you to read the linked issue's last comment in full, that's why I referenced it above. Incremental compilation is not compatible with generating top-level declarations until kotlin 2.3.20