Case class equals with list of byte array

Question

I am trying to use the should matchers on a case class

case class ListOfByteArrayCaseConfig(

  @BeanProperty 
  permissions: java.util.List[Array[Byte]]

)

With the following test case

val orig = ListOfByteArrayCaseConfig(List(Array[Byte](10, 20, 30)))
val orig2 = ListOfByteArrayCaseConfig(List(Array[Byte](10, 20, 30)))

orig2 should be === orig

Obviously this would fail because the two byte arrays are not equal reference wise. What I want to do is somehow make this work without changing the test case code and still keeping the case class.

Is it even possible? (like adding a custom equals method to the case class?)

You are using ScalaTest or Specs2? – om-nom-nom Oct 22 '12 at 21:08 — om-nom-nom, Oct 22 '12 at 21:08

score 2 · Accepted Answer · edited May 23 '17 at 12:18

2

I found the solution. Apparently I can override the equals method in a case class

Scala: Ignore case class field for equals/hascode?

Though it gets rid of the reason for using case classes in the first place which is to simplify data objects.

case class ListOfByteArrayCaseConfig(

  @BeanProperty 
  permissions: java.util.List[Array[Byte]]

) {

  override def equals(arg: Any): Boolean = {

    val obj = arg.asInstanceOf[ListOfByteArrayCaseConfig]
    var i: Int = 0
    for (i <- 0 until permissions.size()) {
      if (!util.Arrays.equals(permissions.get(i), obj.permissions.get(i))) {
        return false
      }
    }
    return true
  }
}

edited May 23 '17 at 12:18

Community

1
1

answered Oct 22 '12 at 21:21

Archimedes Trajano

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4

+1, but you should not assume that object passed to `equals()` is of `ListOfByteArrayCaseConfig` type. Moreover, consider using pattern matching instead of downcasting. – Tomasz Nurkiewicz Oct 22 '12 at 21:29
2

You had better override `hashCode` also if you plan on using this with sets or maps (or just want `hashCode` and `equals` to be consistent). – Rex Kerr Oct 22 '12 at 22:16
True, I just wanted a quick and dirty class to be used for testing, but I agree it needs a hashCode and a proper equals implementation. At the very least this shows what can be done. – Archimedes Trajano Oct 23 '12 at 02:26

Case class equals with list of byte array

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