Fix eachLeft/eachRight

Author: ghostbuster91

core/src/main/scala/com/softwaremill/diffx/ModifyMacro.scala

@@ -97,10 +97,13 @@ object ModifyMacro {
       case q"($arg) => $pathBody " => collectPathElements(pathBody, Nil)
       case _                       => c.abort(c.enclosingPosition, s"$ShapeInfo, got: ${path.tree}")
     }
-
     c.Expr[List[String]](
-      q"(${pathEls.collect { case TermPathElement(c) =>
-        c.decodedName.toString
+      q"(${pathEls.collect {
+        case TermPathElement(c) => c.decodedName.toString
+        case FunctorPathElement(_, method, _ @_*) if method.decodedName.toString == "eachLeft" =>
+          method.decodedName.toString
+        case FunctorPathElement(_, method, _ @_*) if method.decodedName.toString == "eachRight" =>
+          method.decodedName.toString
       }})"
     )
   }

core/src/main/scala/com/softwaremill/diffx/instances/DiffForEither.scala

@@ -9,8 +9,8 @@ private[diffx] class DiffForEither[L, R](ld: Diff[L], rd: Diff[R]) extends Diff[
       context: DiffContext
   ): DiffResult = {
     (left, right) match {
-      case (Left(v1), Left(v2))   => ld.apply(v1, v2, context)
-      case (Right(v1), Right(v2)) => rd.apply(v1, v2, context)
+      case (Left(v1), Left(v2))   => ld.apply(v1, v2, context.getNextStep("eachLeft"))
+      case (Right(v1), Right(v2)) => rd.apply(v1, v2, context.getNextStep("eachRight"))
       case (v1, v2)               => DiffResultValue(v1, v2)
     }
   }

core/src/test/scala/com/softwaremill/diffx/test/DiffModifyIntegrationTest.scala

@@ -47,6 +47,35 @@ class DiffModifyIntegrationTest extends AnyFlatSpec with Matchers {
     compare(o1, o2) shouldBe Identical(Organization(List(p1, p2)))
   }
 
+  it should "ignore only on right" in {
+    case class Wrapper(e: Either[Person, Person])
+    val e1 = Wrapper(Right(p1))
+    val e2 = Wrapper(Right(p1.copy(name = p1.name + "_modified")))
+
+    implicit val wrapperDiff: Diff[Wrapper] = Derived[Diff[Wrapper]].ignore(_.e.eachRight.name)
+
+    compare(e1, e2) shouldBe Identical(e1)
+
+    val e3 = Wrapper(Left(p1))
+    val e4 = Wrapper(Left(p1.copy(name = p1.name + "_modified")))
+
+    compare(e3, e4) should not be an[Identical[_]]
+  }
+
+  it should "ignore only on left" in {
+    case class Wrapper(e: Either[Person, Person])
+    val e1 = Wrapper(Right(p1))
+    val e2 = Wrapper(Right(p1.copy(name = p1.name + "_modified")))
+
+    implicit val wrapperDiff: Diff[Wrapper] = Derived[Diff[Wrapper]].ignore(_.e.eachLeft.name)
+
+    compare(e1, e2) should not be an[Identical[_]]
+    val e3 = Wrapper(Left(p1))
+    val e4 = Wrapper(Left(p1.copy(name = p1.name + "_modified")))
+
+    compare(e3, e4) shouldBe an[Identical[_]]
+  }
+
   it should "match map entries by values" in {
     implicit val lookupDiff: Diff[MyLookup] = Derived[Diff[MyLookup]]
       .modify(_.map)

core/src/test/scala/com/softwaremill/diffx/test/ModifyMacroTest.scala

@@ -14,8 +14,8 @@ class ModifyMacroTest extends AnyFlatSpec with Matchers {
   }
 
   it should "ignore fields in product wrapped with either" in {
-    ModifyMacro.modifiedFromPath[Either[Person, Person], String](_.eachRight.name) shouldBe List("name")
-    ModifyMacro.modifiedFromPath[Either[Person, Person], String](_.eachLeft.name) shouldBe List("name")
+    ModifyMacro.modifiedFromPath[Either[Person, Person], String](_.eachRight.name) shouldBe List("eachRight", "name")
+    ModifyMacro.modifiedFromPath[Either[Person, Person], String](_.eachLeft.name) shouldBe List("eachLeft", "name")
   }
 
   it should "ignore fields in product wrapped with option" in {