Add before() and after() to RichDate

[megaserg]

There are two implicit conversions for RichDate:

• implicit def toDate(rd: RichDate): java.util.Date
• implicit def toCalendar(rd: RichDate)(implicit tz: TimeZone): java.util.Calendar

Each has its own implementation of before() and after() methods:

• Date: boolean before(Date when)
• Calendar: boolean before(Object when)

Their implementation in java.util is pretty much the same (comparing millis), except that Calendar's one does an additional instanceof Calendar check. Therefore, an ambiguous behavior arises:

• Imagine a user writes: d1.before(d2), where d1, d2: RichDate.
• Normally, implicit conversion of d1 to Date will happen, and d1.before(Date when) will be applied to d2 (converted to Date), comparing the millis.
• However, if a user happened to have an implicit TimeZone in the context (as many Scalding job base classes do), implicit conversion of d1 to Calendar will happen, d1.before(Object when) will be applied to d2 (which is a DateRange), and the instanceof check will fail the comparison. before() will always return false!

Solution: define before() and after() methods directly in RichDate. This way, implicit conversion will not have to take place.

Complete example to reproduce. Comment/uncomment tz declaration to print true or false.

import java.util.TimeZone

import com.twitter.scalding._

object TestingImpl {
//  implicit val tz: TimeZone = TimeZone.getDefault

  val d1 = RichDate(1294239559)
  val d2 = RichDate(1295239559)

  def main(args: Array[String]) = {
    println (d1.before(d2))
  }
}

[benpence]

@megaserg Can you add a test case that fails the instanceofcheck without these methods and succeeds with their addition?

[johnynek]

let's not have this

[megaserg]

Uncommented. It would be failing even if I would remove the comment, but then the validness of the test would depend on that implicit tz on the top level (which someone someday might decide to remove, rendering my test trivial).

[benpence]

+1 The test fails when I run it in the console on scalding/develop

[johnynek]

Thanks for the contribution!