Multiple bean definitions (Conflicts)

Your documentation says “latest bean wins” (See https://insert-koin.io/docs/1.0/reference/koin-dsl/?#multiple-definitions)

The source code throws an exception if there are multiple beans: see https://github.com/Ekito/koin/blob/0.9.1/koin-core/src/main/kotlin/org/koin/KoinContext.kt#L121

In case future readers face this,

My use case: I want to override/replace/shadow specific beans with mocks/spies in my unit/integration tests.

My solution was to

• Register all the normal application beans (eg. via startKoin)
• Create a BeanDefinition instance for each mock/spy/fake
• Register them manually koin.beanRegistry.declare( theBeanDef , Scope.root())

[arnaudgiuliani]

If you want to reuse a module and override some definitions for your test, just make a module containing your new definitions and load modules in order: your app + your test module

The last module will override needed definitions

A bean is overriden when: same name, type and scope

You can match multiple bean for a given type if you use bind oeprators then

[wcarmon]

Of course you are correct about KoinTest being an interface. Clearly I didn’t look into KoinTest at all.

As you mentioned, the root cause appears to be a choice of eager-injection versus lazy-injection.

I still prefer “immutable-after-construction” & eager injection, so I’ll use the workaround above.

Thanks for the helpful information.