fix: transform into classes with var fields

chimney-macro-commons/src/main/scala-2/io/scalaland/chimney/internal/compiletime/datatypes/ProductTypesPlatform.scala

@@ -156,7 +156,7 @@ trait ProductTypesPlatform extends ProductTypes { this: DefinitionsPlatform =>
               // We have to drop that suffix to align names, so that comparing is possible.
               val n: String = getDecodedName(setter)
               val name =
-                if (isVar(setter)) n.substring(0, n.length - "_$eq".length) else n
+                if (isVar(setter)) n.stripSuffix("_$eq").stripSuffix("_=") else n
               name -> setter
             }
             .filter { case (name, _) => !paramTypes.keySet.exists(areNamesMatching(_, name)) }

chimney/src/test/scala/io/scalaland/chimney/IssuesSpec.scala

@@ -672,4 +672,15 @@ class IssuesSpec extends ChimneySpec {
     Bar("b").transformInto[Foo] ==> Foo("b")
     Foo("b").into[Bar2].withFieldConst(_.number, 3).transform ==> Bar2("b", 3)
   }
+
+  test("fix issue #400") {
+    import Issue400.*
+
+    Foo("b").transformInto[Bar] ==> Bar("b")
+    Foo("b").into[Bar].transform ==> Bar("b")
+    Foo("b").transformIntoPartial[Bar].asOption ==> Some(Bar("b"))
+    Foo("b").intoPartial[Bar].transform.asOption ==> Some(Bar("b"))
+    Foo("b").into[Bar2].enableDefaultValues.transform ==> Bar2("b", "ok")
+    Foo("b").intoPartial[Bar2].enableDefaultValues.transform.asOption ==> Some(Bar2("b", "ok"))
+  }
 }

chimney/src/test/scala/io/scalaland/chimney/fixtures/Issues.scala

@@ -170,3 +170,9 @@ object Issue297 {
   case class Bar(value: String)
   case class Bar2(value: String, number: Int)
 }
+
+object Issue400 {
+  case class Foo(value: String)
+  case class Bar(var value: String)
+  case class Bar2(var value: String, var value2: String = "ok")
+}