I have an abstract class

A

that has an abstract member property defined by an interface:

interface Tool {
  fun run(command: String): Boolean
}

abstract class A {
  abstract protected var tool: Tool
  fun execute(command: String) : Boolean {
    return tool.run(command)
  }
}

Then I have another class

B

that inherits from

A

and uses guice to inject the

tool

member property at startup.

class B {
  @Inject
  @Transient
  override protected var tool: Knife
}

where

Knife

is a concrete class implementing the interface

Tool

. Intellij is complaining to me:

Var property tye is `Knife`, which is not a type of overridden protected abstract var tool: Tool defined in com.myorg....

.

@wei The problem is

var

combined with using a subtype of

Tool

, e.g. the following example fails:

val b = B()
val a: A = b

a.tool = Drill() //Fails at runtime, because B.tool must be a Knife, but Drill is used

You can use guice contructor injection and use a

val

or set the type of

B.tool

to

Tool