Prod issue

app/uk/gov/hmrc/tai/model/domain/TaxCodeChange.scala

@@ -25,11 +25,11 @@ case class TaxCodeChange(previous: List[TaxCodeRecord], current: List[TaxCodeRec
 
   require(current.nonEmpty, "No current records for Tax Code Change. Current date cannot be determined.")
 
-  val currentPensionCount: Int                       = current.count(_.pensionIndicator)
-  val currentEmploymentCount: Int                    = current.count(!_.pensionIndicator)
-  val mostRecentTaxCodeChangeDate: LocalDate         = DateHelper.mostRecentDate(current.map(_.startDate))
-  val mostRecentPreviousTaxCodeChangeDate: LocalDate =
-    DateHelper.mostRecentDate(previous.map(_.startDate))
+  val currentPensionCount: Int                               = current.count(_.pensionIndicator)
+  val currentEmploymentCount: Int                            = current.count(!_.pensionIndicator)
+  val mostRecentTaxCodeChangeDate: LocalDate                 = DateHelper.mostRecentDate(current.map(_.startDate))
+  val mostRecentPreviousTaxCodeChangeDate: Option[LocalDate] =
+    DateHelper.mostRecentDateOption(previous.map(_.startDate))
 
   lazy val uniqueTaxCodes: Seq[String] = (previous ++ current).map(_.taxCode).distinct
 }

app/uk/gov/hmrc/tai/util/DateHelper.scala

@@ -34,6 +34,9 @@ object DateHelper {
   def mostRecentDate(dates: Seq[LocalDate]): LocalDate =
     dates.min
 
+  def mostRecentDateOption(dates: Seq[LocalDate]): Option[LocalDate] =
+    dates.reduceOption((a, b) => if (a.isAfter(b)) a else b)
+
   def monthOfYear(date: String): String = {
     val monthRegex = "[A-Za-z]+".r
     monthRegex.findFirstIn(date).getOrElse("")

test/uk/gov/hmrc/tai/model/domain/TaxCodeChangeSpec.scala

@@ -56,7 +56,7 @@ class TaxCodeChangeSpec extends PlaySpec {
         val model =
           TaxCodeChange(List(previousTaxCodeRecord1, fullYearTaxCode), List(currentTaxCodeRecord1, fullYearTaxCode))
 
-        model.mostRecentPreviousTaxCodeChangeDate mustEqual startDate
+        model.mostRecentPreviousTaxCodeChangeDate mustEqual Some(startDate)
       }
     }