Add toValidatedNec to Validated (#2487)

* add toValidatedNec to Validated * add test for toValidatedNec
typelevel · Sep 24, 2018 · e5a6c91 · e5a6c91
1 parent 33f5c5b
commit e5a6c91
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diff --git a/core/src/main/scala/cats/data/Validated.scala b/core/src/main/scala/cats/data/Validated.scala
@@ -128,6 +128,13 @@ sealed abstract class Validated[+E, +A] extends Product with Serializable {
       case Invalid(e)  => Validated.invalidNel(e)
     }
 
+  /** Lift the Invalid value into a NonEmptyChain. */
+  def toValidatedNec[EE >: E, AA >: A]: ValidatedNec[EE, AA] =
+    this match {
+      case v @ Valid(_) => v
+      case Invalid(e)  => Validated.invalidNec(e)
+    }
+
   /**
    * Convert to an Either, apply a function, convert back.  This is handy
    * when you want to use the Monadic properties of the Either type.

diff --git a/tests/src/test/scala/cats/tests/ValidatedSuite.scala b/tests/src/test/scala/cats/tests/ValidatedSuite.scala
@@ -91,6 +91,14 @@ class ValidatedSuite extends CatsSuite {
     }
   }
 
+  test("ValidatedNec") {
+    forAll { (e: String) ⇒
+      val manual = Validated.invalid[NonEmptyChain[String], Int](NonEmptyChain.one(e))
+      Validated.invalidNec[String, Int](e) should === (manual)
+      Validated.invalid[String, Int](e).toValidatedNec should === (manual)
+    }
+  }
+
   test("isInvalid consistent with forall and exists") {
     forAll { (v: Validated[String, Int], p: Int => Boolean) =>
       if (v.isInvalid) {