fix auto-derivation using custom instances

modules/core/src/main/scala-2/doobie/util/GetPlatform.scala

@@ -11,13 +11,17 @@ trait GetPlatform {
   import doobie.util.compat.=:=
 
   /** @group Instances */
-  @deprecated("Use Get.derived instead to derive instances explicitly", "1.0.0-RC6")
+  @deprecated("Use Get#contramap to construct the instance or Read.derived, " +
+    "which yields the equivalent runtime behaviour", "1.0.0-RC7")
   def unaryProductGet[A, L <: HList, H, T <: HList](
       implicit
       G: Generic.Aux[A, L],
       C: IsHCons.Aux[L, H, T],
       H: Lazy[Get[H]],
       E: (H :: HNil) =:= L
-  ): MkGet[A] = MkGet.unaryProductGet
+  ): Get[A] = {
+    void(C) // C drives inference but is not used directly
+    H.value.tmap[A](h => G.from(h :: HNil))
+  }
 
 }

modules/core/src/main/scala-2/doobie/util/PutPlatform.scala

@@ -11,13 +11,16 @@ trait PutPlatform {
   import doobie.util.compat.=:=
 
   /** @group Instances */
-  @deprecated("Use Put.derived instead to derive instances explicitly", "1.0.0-RC6")
+  @deprecated("Use contramap or Write.derived, which yields the equivalent runtime behaviour", "1.0.0-RC7")
   def unaryProductPut[A, L <: HList, H, T <: HList](
       implicit
       G: Generic.Aux[A, L],
       C: IsHCons.Aux[L, H, T],
       H: Lazy[Put[H]],
       E: (H :: HNil) =:= L
-  ): MkPut[A] = MkPut.unaryProductPut
+  ): Put[A] = {
+    void(E) // E is a necessary constraint but isn't used directly
+    H.value.contramap[A](a => G.to(a).head)
+  }
 
 }

modules/core/src/main/scala-3/doobie/util/PutPlatform.scala

@@ -4,4 +4,4 @@
 
 package doobie.util
 
-trait PutPlatform {}
+trait PutPlatform

modules/core/src/main/scala/doobie/generic/auto.scala

@@ -4,19 +4,10 @@
 
 package doobie.generic
 
-import doobie.util.meta.Meta
-import doobie.util.{Get, Put, Read, Write}
+import doobie.util.{Read, Write}
 
 trait AutoDerivation
-    extends Get.Auto
-    with Put.Auto
-    with Read.Auto
+    extends Read.Auto
     with Write.Auto
 
-object auto extends AutoDerivation {
-
-  // FIXME: move to AutoDerivation trait itself so shares with doobie.implicits
-  // re-export these instances so `Meta` takes priority, must be in the object
-  implicit def metaProjectionGet[A](implicit m: Meta[A]): Get[A] = Get.metaProjection
-  implicit def metaProjectionPut[A](implicit m: Meta[A]): Put[A] = Put.metaProjectionWrite
-}
+object auto extends AutoDerivation

modules/core/src/main/scala/doobie/package.scala

@@ -2,7 +2,6 @@
 // This software is licensed under the MIT License (MIT).
 // For more information see LICENSE or https://opensource.org/licenses/MIT
 
-import doobie.util.{Get, Put}
 import doobie.util.meta.{LegacyMeta, TimeMetaInstances}
 // Copyright (c) 2013-2020 Rob Norris and Contributors
 // This software is licensed under the MIT License (MIT).
@@ -30,11 +29,6 @@ package object doobie
       with LegacyMeta
       with syntax.AllSyntax {
 
-    // FIXME: do we still need these?
-    // re-export these instances so `Meta` takes priority, must be in the object
-    implicit def metaProjectionGet[A](implicit m: Meta[A]): Get[A] = Get.metaProjection
-    implicit def metaProjectionPut[A](implicit m: Meta[A]): Put[A] = Put.metaProjectionWrite
-
     /** Only use this import if:
       *   1. You're NOT using one of the database doobie has direct java.time isntances for (PostgreSQL / MySQL). (They
       *      have more accurate column type checks) 2. Your driver natively supports java.time.* types

modules/core/src/main/scala/doobie/util/get.scala

@@ -84,12 +84,6 @@ object Get extends GetInstances with GetPlatform {
 
   def apply[A](implicit ev: Get[A]): ev.type = ev
 
-  def derived[A](implicit ev: MkGet[A]): Get[A] = ev
-
-  trait Auto {
-    implicit def deriveGet[A](implicit ev: MkGet[A]): Get[A] = ev
-  }
-
   /** Get instance for a basic JDBC type. */
   object Basic {
 
@@ -213,23 +207,3 @@ trait GetInstances {
     ev.tmap(_.toVector)
 
 }
-
-sealed abstract class MkGet[A](
-    override val typeStack: NonEmptyList[Option[String]],
-    override val jdbcSources: NonEmptyList[JdbcType],
-    override val jdbcSourceSecondary: List[JdbcType],
-    override val vendorTypeNames: List[String],
-    override val get: Coyoneda[(ResultSet, Int) => *, A]
-) extends Get[A](typeStack, jdbcSources, jdbcSourceSecondary, vendorTypeNames, get)
-
-object MkGet extends MkGetPlatform {
-
-  def lift[A](g: Get[A]): MkGet[A] =
-    new MkGet[A](
-      typeStack = g.typeStack,
-      jdbcSources = g.jdbcSources,
-      jdbcSourceSecondary = g.jdbcSourceSecondary,
-      vendorTypeNames = g.vendorTypeNames,
-      get = g.get
-    ) {}
-}

modules/core/src/main/scala/doobie/util/put.scala

@@ -82,16 +82,10 @@ sealed abstract class Put[A](
 
 }
 
-object Put extends PutInstances with PutPlatform {
+object Put extends PutInstances {
 
   def apply[A](implicit ev: Put[A]): ev.type = ev
 
-  def derived[A](implicit ev: MkPut[A]): Put[A] = ev
-
-  trait Auto {
-    implicit def derivePut[A](implicit ev: MkPut[A]): Put[A] = ev
-  }
-
   object Basic {
 
     def apply[A](
@@ -208,7 +202,7 @@ object Put extends PutInstances with PutPlatform {
 
 }
 
-trait PutInstances {
+trait PutInstances extends PutPlatform {
 
   /** @group Instances */
   implicit val ContravariantPut: Contravariant[Put] =
@@ -226,23 +220,3 @@ trait PutInstances {
     ev.tcontramap(_.toArray)
 
 }
-
-sealed abstract class MkPut[A](
-    override val typeStack: NonEmptyList[Option[String]],
-    override val jdbcTargets: NonEmptyList[JdbcType],
-    override val vendorTypeNames: List[String],
-    override val put: ContravariantCoyoneda[(PreparedStatement, Int, *) => Unit, A],
-    override val update: ContravariantCoyoneda[(ResultSet, Int, *) => Unit, A]
-) extends Put[A](typeStack, jdbcTargets, vendorTypeNames, put, update)
-
-object MkPut extends MkPutPlatform {
-
-  def lift[A](g: Put[A]): MkPut[A] =
-    new MkPut[A](
-      typeStack = g.typeStack,
-      jdbcTargets = g.jdbcTargets,
-      vendorTypeNames = g.vendorTypeNames,
-      put = g.put,
-      update = g.update
-    ) {}
-}

modules/core/src/test/scala-2/doobie/util/QueryLogSuitePlatform.scala

@@ -8,7 +8,6 @@ import doobie.util.log.{Parameters, ProcessingFailure, Success}
 import shapeless._
 
 trait QueryLogSuitePlatform { self: QueryLogSuite =>
-  import doobie.generic.auto._
 
   test("[Query] n-arg success") {
     val Sql = "select 1 where ? = ?"