auto-detect @Inject method parameter types

[dev-qnz]

weld-testing/junit5/README.md

Line 5 in b2c1c6f

In their default behaviour, the extensions will automatically start/stop Weld SE container and inject into all your `@Inject` fields and method parameters in the given test instance.

says that the extension will

inject into all your @Inject fields and method parameters in the given test instance

However, it looks like only the field type is detected and added to the container and not the method parameter type.

Also,

    private Foo foo;

    @Inject
    private void setFoo(Foo foo) {
        this.foo = foo;
    }

should essentially be short for

    @Inject
    private Foo foo;

But only the field injection works as of now as far as I figure

[manovotn]

weld-testing/junit5/README.md

Line 5 in b2c1c6f

In their default behaviour, the extensions will automatically start/stop Weld SE container and inject into all your `@Inject` fields and method parameters in the given test instance.

says that the extension will

inject into all your @Inject fields and method parameters in the given test instance

However, it looks like only the field type is detected and added to the container and not the method parameter type.

Yes, the README talks about what Weld tries to inject (mainly due to its greedy nature) and not really about what it scans in the auto-mode.

Also,

    private Foo foo;

    @Inject
    private void setFoo(Foo foo) {
        this.foo = foo;
    }

should essentially be short for

    @Inject
    private Foo foo;

But only the field injection works as of now as far as I figure

The two injections shouldn't be equal, at least not in case of junit - test instances used by junit are not beans provided by Weld meaning declaring an initializer in there makes little sense.
There was a discussion leading to this gotcha in #156 and also in #144

[manovotn]

Ok, I was fairly surprised why this works in the first place but now I see why.

We treat the test instance as an InjectionTarget where we invoke injectionTarget.inject(...) - this, among other things, means that it will look for initializer and invoke that as well.

[dev-qnz]

Honestly, I haven't understood the purpose of getReturnType as it was there before. I also can't find initializer method return types mentioned in the specs (https://jakarta.ee/specifications/cdi/4.0/jakarta-cdi-spec-4.0#declaring_initializer). Could it possibly have been a bug, here, to evaluate the return type or shall that be kept and if so what for?
It may not hurt if it works now, regardless of how the test is instantiated.

[manovotn]

I didn't understand it either and did some digging too - I think it's a bug/oversight from when the annotation based approach was added.
In CDI, @Inject usage on methods is basically either initializer or annotated constructor neither of which has interesting return type that we should process here.

[manovotn]

Thanks for the PR!