Surprising implicit resolutions with package objects

example.scala

package com

package object example {
  implicit class FooImplicit(val foo: Any) {
    def fooImplicit = ???
  }
}

Test.scala

package com.example

class Test {
  // This works
  (_: Int).fooImplicit
}

Test2.scala

package com.example.subpackage

class Test2 {
  // This does not work
  (_: Int).fooImplicit
  // This works
  this.fooImplicit
}

Test3.scala

package com.example2

class Test3 {
  // This does not work
  (_: Int).fooImplicit
  // This does work
  (_: com.example.Test).fooImplicit
}

The key takeaway here is that it is the scope of the type that is searched and not the scope of where it is used, except for the package object of the same package (not parent packages).