Make schema val @transient in ParquetType (#619)

* Make schema val @transient in ParquetType

* fix test

* Fixing the Avro compat error in serialization test (#620)

Co-authored-by: Claire McGinty <clairem@spotify.com>

Co-authored-by: Andrew Kabas <kabas.andrew@gmail.com>

parquet/src/main/scala/magnolify/parquet/ParquetType.scala

@@ -86,8 +86,8 @@ object ParquetType {
  )(implicit f: ParquetField[T], pa: ParquetArray): ParquetType[T] = f match {
  case r: ParquetField.Record[_] =>
  new ParquetType[T] {
- override lazy val schema: MessageType = Schema.message(r.schema(cm))
- override lazy val avroSchema: AvroSchema = {
+ @transient override lazy val schema: MessageType = Schema.message(r.schema(cm))
+ @transient override lazy val avroSchema: AvroSchema = {
  val s = new AvroSchemaConverter().convert(schema)
  // add doc to avro schema
  SchemaUtil.deepCopy(s, f.typeDoc, f.fieldDocs.get)

parquet/src/test/scala/magnolify/parquet/AvroParquetSuite.scala

@@ -49,9 +49,14 @@ class AvroParquetSuite extends MagnolifySuite {
  schemaErrors: List[String] = List.empty
  )(implicit
  at: AvroType[T],
- pt: ParquetType[T],
+ tpe: ParquetType[T],
  eq: Eq[T]
  ): Unit = {
+ // Ensure serializable even after evaluation of `schema` and `avroSchema`
+ val parquetSchema = tpe.schema
+ val avroSchema = tpe.avroSchema
+ val pt = ensureSerializable(tpe)
+
  val name = className[T]
 
  property(s"$name.avro2parquet") {

parquet/src/test/scala/magnolify/parquet/ParquetTypeSuite.scala

@@ -44,7 +44,10 @@ class ParquetTypeSuite extends MagnolifySuite {
  t: ParquetType[T],
  eq: Eq[T]
  ): Unit = {
+ // Ensure serializable even after evaluation of `schema`
+ val parquetSchema = t.schema
  val tpe = ensureSerializable(t)
+
  property(className[T]) {
  Prop.forAll { t: T =>
  val out = new TestOutputFile