Support bijection in OptionDefaultVisitor

modules/bootstrapped/test/src/smithy4s/http/MetadataDecoderSpec.scala

@@ -0,0 +1,44 @@
+package smithy4s.http
+
+import munit._
+import smithy4s.schema.Schema
+import smithy.api
+// import smithy4s.schema.Field
+
+final class MetadataDecoderSpec extends FunSuite {
+  test("Optional header") {
+    case class Foo(deviceType: Option[String])
+    val schema =
+      Schema
+        .struct(
+          Schema.string
+            .optional[Foo]("deviceType", _.deviceType)
+            .addHints(api.HttpHeader("x-device-type"))
+            .addHints(api.Input())
+        )(Foo(_))
+        .addHints(smithy4s.internals.InputOutput.Input.widen)
+
+    val decoder = Metadata.Decoder.fromSchema(schema)
+    val result = decoder.decode(Metadata())
+
+    assertEquals(result, Right(Foo(None)))
+  }
+
+  test("Optional bijection header") {
+    case class Foo(name: Option[String])
+    val schema: Schema[Foo] = {
+      val field = Schema.string.option
+        .biject[Option[String]](identity[Option[String]](_))(identity(_))
+        .required[Foo]("name", _.name)
+        .addHints(smithy.api.HttpHeader("X-Name"))
+      Schema
+        .struct(field)(Foo(_))
+        .addHints(smithy4s.internals.InputOutput.Input.widen)
+    }
+
+    val decoder = Metadata.Decoder.fromSchema(schema)
+    val result = decoder.decode(Metadata())
+
+    assertEquals(result, Right(Foo(None)))
+  }
+}

modules/core/src/smithy4s/schema/Schema.scala

@@ -291,6 +291,8 @@ object Schema {
   private object OptionDefaultVisitor extends SchemaVisitor.Default[Option] {
     def default[A] : Option[A] = None
     override def option[A](schema: Schema[A]) : Option[Option[A]] = Some(None)
+    override def biject[A, B](schema: Schema[A], bijection: Bijection[A, B]): Option[B] =
+      this.apply(schema).map(bijection.to)
   }
 
   def operation(id: ShapeId): OperationSchema[Unit, Nothing, Unit, Nothing, Nothing] =