Add extendable controller & configuration for setup

[KiKoS0]

I think someone with better spring boot knowledge can shape
a better interface to create the Inngest client + CommHandler but
this is already better than manually creating a singleton and
having everything in a random controller.

Note: It might be better to not have a second adapter package and
instead have these spring boot helpers as a feature variant. But
I'll see how it goes with this PR first: #27

I'm also adding a way to build the Inngest client configuration
possibly through a Builder pattern targeted to the specific
environment that the user wants to use.

The current interface (which needs better code documentation) is that a consumer application would subclass the controller and configuration as follows:

ExampleController.java

@RestController
@RequestMapping(value = "/api/inngest")
public class ExampleController extends InngestController {
}

ExampleConfiguration.java

@Configuration
public class ExampleConfiguration extends InngestConfiguration {

    @Override
    public HashMap<String, InngestFunction> functions() {
        HashMap<String, InngestFunction> functions = new HashMap<>();
        ...
        return functions;
    }

    @Override
    public Inngest inngestClient() {
        return new Inngest("spring_example");
    }
}

[darwin67]

This is fine for now.
The idea of #27 is that there will be a serve function that will handle all the routes, and also take the Inngest client as an input so the route handler will have all the information it needs.

Having some compilation error locally, so haven't push the latest code up yet.

[darwin67]

this is the latest code, and kotlin is not happy about something, but can't tell what it is.
https://github.com/inngest/inngest-kt/pull/27/files#diff-a53270cbe78c3842c55b0a20286bd726f41e9e697070455fb5f75c0fb73a4104R15

[KiKoS0]

oh it was the Kotlin paratrooped it. 😏

[darwin67]

yeah, I just figured it out. annoying

[albertchae]

probably best to version all the subpackages of inngest-kt together. I think there's something we can add in the root gradle file. I'll take a note of this for now

[albertchae]

we already discussed this but probably ideal if we don't have to pull in a kotlin Function here and can instead use lambdas (available in Java 8) or something like https://docs.oracle.com/javase/8/docs/api/java/lang/Runnable.html