Option to either conversion

scala-core-modules/scala-core-9/src/test/scala/com/baeldung/scala/optiontoeither/OptionToEitherUnitTest.scala

@@ -0,0 +1,82 @@
+package com.baeldung.scala.optiontoeither
+
+import org.scalatest.matchers.should.Matchers
+import org.scalatest.wordspec.AnyWordSpec
+
+sealed trait Error
+case object EmptyOptionValue extends Error
+
+class OptionToEitherUnitTest extends AnyWordSpec with Matchers {
+
+  def usingIfElse(option: Option[String]): Either[Error, String] = {
+    if (option.isDefined) Right(option.get) else Left(EmptyOptionValue)
+  }
+
+  def usingPatternMatch(option: Option[String]): Either[Error, String] = {
+    option match {
+      case Some(value) => Right(value)
+      case None        => Left(EmptyOptionValue)
+    }
+  }
+
+  def usingToRight(option: Option[String]): Either[Error, String] = {
+    option.toRight(EmptyOptionValue)
+  }
+
+  def usingCond(option: Option[String]): Either[Error, String] = {
+    Either.cond(option.nonEmpty, option.get, EmptyOptionValue)
+  }
+
+  def usingFold(option: Option[String]): Either[Error, String] = {
+    option.fold(Left(EmptyOptionValue))(Right(_))
+  }
+
+  def usingMap(option: Option[String]): Either[Error, String] = {
+    option.map(Right(_)).getOrElse(Left(EmptyOptionValue))
+  }
+
+  "Option" should {
+    "be converted to Either using if else" in {
+      val either = usingIfElse(Option("Baeldung"))
+      either shouldBe Right("Baeldung")
+      val left = usingIfElse(None)
+      left shouldBe Left(EmptyOptionValue)
+    }
+
+    "be converted to Either using pattern matching" in {
+      val either = usingPatternMatch(Option("Baeldung"))
+      either shouldBe Right("Baeldung")
+      val left = usingPatternMatch(None)
+      left shouldBe Left(EmptyOptionValue)
+    }
+
+    "be converted to Either using usingToRight" in {
+      val either = usingToRight(Option("Baeldung"))
+      either shouldBe Right("Baeldung")
+      val left = usingToRight(None)
+      left shouldBe Left(EmptyOptionValue)
+    }
+
+    "be converted to Either using usingCond" in {
+      val either = usingCond(Option("Baeldung"))
+      either shouldBe Right("Baeldung")
+      val left = usingCond(None)
+      left shouldBe Left(EmptyOptionValue)
+    }
+
+    "be converted to Either using fold" in {
+      val either = usingFold(Option("Baeldung"))
+      either shouldBe Right("Baeldung")
+      val left = usingFold(None)
+      left shouldBe Left(EmptyOptionValue)
+    }
+
+    "be converted to Either using map" in {
+      val either = usingMap(Option("Baeldung"))
+      either shouldBe Right("Baeldung")
+      val left = usingMap(None)
+      left shouldBe Left(EmptyOptionValue)
+    }
+  }
+
+}