Can't inject provided dependency into java class

[sergeshustoff]

Problem: when there is a java class in dependency graph we have to create @Provides function in component in order to inject it - having @Inject annotation on that's java class' constructor doesn't work.

I'm not sure if it's ksp limitation or not, will need to research that...

[evant]

It should work in theory, there's even a test for it here, https://github.com/evant/kotlin-inject/blob/main/integration-tests/common-jvm/src/test/kotlin/me/tatarka/inject/test/JavaTest.kt, but it's possible there may be an issue with it, any chance you can create a sample the reproduces?

[sergeshustoff]

Looks like my complicated setup breaks in some corner case. I'll try find a simple case to reproduce it

[sergeshustoff]

failing_provided_injection_in_java_class.patch Ok, here is a patch to make test fail. Looks like anything that component @Provides doesn't get injected into java constructor

// in JavaTest
@Component
abstract class JavaInjectConstructorComponent {
    abstract val foo: JavaFoo

    @Provides
    fun Foo.bind(): IFoo = this

    abstract val foo2: JavaJavaXFoo
}

// in java file
public class JavaFoo {

    private final IFoo foo;

    @Inject
    public JavaFoo(IFoo foo) {
        this.foo = foo;
    }

    public IFoo getFoo() {
        return foo;
    }
}

[sergeshustoff]

Adding org.jetbrains.annotations.NotNull annotation (androidx annotation works too) to java class constructor parameters fixes the problem.

Seems that the right way to fix it would be to show message similar to one in #110 for dependency types

[sergeshustoff]

Though there is a strange difference in behaviour for things provided by inject constructor and provided explicidly

                // java code
                public class JavaIFoo  {

                    private final Foo foo;

                    @Inject
                    public JavaIFoo(Foo foo) {
                        this.foo = foo;
                    }

                    public Foo getFoo() {
                        return foo;
                    }
                }

                // kotlin code
                @Inject 
                class Foo

                @Component
                abstract class JavaProvidedDependencyComponent {
                    abstract val javaFoo: JavaIFoo

                // @Provides fun foo() = Foo
                }

It works like this, but if @Inject is commented on Foo and @Provides is uncommented - it stops working. I'm not sure anymore what the behavioud should be