Add NonEmptyMap#toNonEmptyList (issue #2346)

typelevel · Sep 26, 2018 · 66d8957 · 66d8957
1 parent 018cb0f
commit 66d8957
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diff --git a/core/src/main/scala/cats/data/NonEmptyMapImpl.scala b/core/src/main/scala/cats/data/NonEmptyMapImpl.scala
@@ -250,6 +250,10 @@ sealed class NonEmptyMapOps[K, A](val value: NonEmptyMap[K, A]) {
     */
   def length: Int = toSortedMap.size
 
+  /**
+    * Returns a non empty list of map contents, similarly to Map#toList
+    */
+  def toNel: NonEmptyList[(K, A)] = NonEmptyList.fromListUnsafe(toSortedMap.toList)
 }
 
 private[data] sealed abstract class NonEmptyMapInstances {

diff --git a/tests/src/test/scala/cats/tests/NonEmptyMapSuite.scala b/tests/src/test/scala/cats/tests/NonEmptyMapSuite.scala
@@ -201,4 +201,10 @@ class NonEmptyMapSuite extends CatsSuite {
       nem.length should ===(nem.toSortedMap.size)
     }
   }
+
+  test("NonEmptyMap#toNonEmptyList is consistent with Map#toList and creating NonEmptyList from it"){
+    forAll{ nem: NonEmptyMap[String, Int] =>
+      nem.toNel should ===(NonEmptyList.fromListUnsafe(nem.toSortedMap.toList))
+    }
+  }
 }