From 5d08d1b8736f718c751966dc48849cdffbf716ee Mon Sep 17 00:00:00 2001
From: Jacob Wang <jatcwang@gmail.com>
Date: Tue, 27 Jul 2021 21:57:46 +0100
Subject: [PATCH] Add instances for Option and Either

---
 .../src/main/scala/difflicious/Differ.scala   |  3 +
 .../test/scala/difflicious/DifferSpec.scala   | 65 +++++++++++++++++++
 2 files changed, 68 insertions(+)

diff --git a/modules/core/src/main/scala/difflicious/Differ.scala b/modules/core/src/main/scala/difflicious/Differ.scala
index 5a51f4d..e95f276 100644
--- a/modules/core/src/main/scala/difflicious/Differ.scala
+++ b/modules/core/src/main/scala/difflicious/Differ.scala
@@ -72,6 +72,9 @@ object Differ extends DifferTupleInstances with DifferGen with DifferTimeInstanc
   implicit val bigDecimalDiffer: NumericDiffer[BigDecimal] = NumericDiffer.make[BigDecimal]
   implicit val bigIntDiffer: NumericDiffer[BigInt] = NumericDiffer.make[BigInt]
 
+  implicit def optionDiffer[T: Differ]: Differ[Option[T]] = derived[Option[T]]
+  implicit def eitherDiffer[A: Differ, B: Differ]: Differ[Either[A, B]] = derived[Either[A, B]]
+
   implicit def mapDiffer[M[_, _], K, V](
     implicit keyDiffer: ValueDiffer[K],
     valueDiffer: Differ[V],
diff --git a/modules/coretest/src/test/scala/difflicious/DifferSpec.scala b/modules/coretest/src/test/scala/difflicious/DifferSpec.scala
index 2b4fa79..5a84a89 100644
--- a/modules/coretest/src/test/scala/difflicious/DifferSpec.scala
+++ b/modules/coretest/src/test/scala/difflicious/DifferSpec.scala
@@ -121,6 +121,71 @@ class DifferSpec extends ScalaCheckSuite {
     )
   }
 
+  test("Option: fail if one is Some and one is None") {
+    assertConsoleDiffOutput(
+      Differ[Option[CC]],
+      Some(CC(2, "2", 3.0)),
+      None,
+      s"""${R}Some$X != ${G}None$X
+         |${R}=== Obtained ===
+         |Some(
+         |  value: CC(
+         |    i: 2,
+         |    s: "2",
+         |    dd: 3.0,
+         |  ),
+         |)$X
+         |${G}=== Expected ===
+         |None(
+         |)$X""".stripMargin,
+    )
+  }
+
+  test("Option: isOk == true if two values are equal") {
+    assertOkIfValuesEqualProp(Differ[Option[CC]])
+  }
+
+  test("Option: isOk == false if two values are NOT equal") {
+    assertNotOkIfNotEqualProp(Differ[Option[CC]])
+  }
+
+  test("Option: isOk always true if differ is marked ignored") {
+    assertIsOkIfIgnoredProp(Differ[Option[CC]])
+  }
+
+  test("Either: fail if one is Some and one is None") {
+    assertConsoleDiffOutput(
+      Differ[Either[String, CC]],
+      Right(CC(2, "2", 3.0)),
+      Left("nope"),
+      s"""${R}Right$X != ${G}Left$X
+         |${R}=== Obtained ===
+         |Right(
+         |  value: CC(
+         |    i: 2,
+         |    s: "2",
+         |    dd: 3.0,
+         |  ),
+         |)$X
+         |${G}=== Expected ===
+         |Left(
+         |  value: "nope",
+         |)$X""".stripMargin,
+    )
+  }
+
+  test("Either: isOk == true if two values are equal") {
+    assertOkIfValuesEqualProp(Differ[Either[String, CC]])
+  }
+
+  test("Either: isOk == false if two values are NOT equal") {
+    assertNotOkIfNotEqualProp(Differ[Either[String, CC]])
+  }
+
+  test("Either: isOk always true if differ is marked ignored") {
+    assertIsOkIfIgnoredProp(Differ[Either[String, CC]])
+  }
+
   test("Map: isOk == true if two values are equal") {
     assertOkIfValuesEqualProp(Differ.mapDiffer[Map, MapKey, CC])
   }