Converting Smithy4s Schemas and Services to Smithy

Using the smithy4s dynamic module you can convert a smithy4s service or schema into a smithy model. This guide will walk through the steps to do this.

Creating a DynamicSchemaIndex

The first step is to take the services and schemas you'd like included in your smithy model and add them to a DynamicSchemaIndex using the provided builder.

import smithy4s.dynamic.DynamicSchemaIndex

val dynamicSchemaIndex = DynamicSchemaIndex.builder
  .addService[smithy4s.example.KVStoreGen]
  .addSchema[smithy4s.example.FaceCard]
  .build()
// dynamicSchemaIndex: DynamicSchemaIndex = smithy4s.dynamic.DynamicSchemaIndex$BuilderImpl$$anon$1@4ac6bdb8

Converting to Smithy Model

Now that we have a DynamicSchemaIndex, we can convert to a smithy model object from the smithy-model Java library. This feature is only supported on the JVM and not ScalaJS or Scala Native.

val model = dynamicSchemaIndex.toSmithyModel
// model: software.amazon.smithy.model.Model = software.amazon.smithy.model.Model@38521e1d

Rendering as a String

If you wish to render the smithy Model as a String, smithy-model provides a method to accomplish this.

import software.amazon.smithy.model.shapes.SmithyIdlModelSerializer
import scala.jdk.CollectionConverters._
import java.nio.file.Path

val smithyFiles: Map[Path, String] = 
  SmithyIdlModelSerializer
      .builder()
      .build()
      .serialize(model)
      .asScala
      .toMap
// smithyFiles: Map[Path, String] = Map(
//   smithy4s.example.smithy -> """$version: "2.0"
// 
// namespace smithy4s.example
// 
// service KVStore {
//     operations: [
//         Delete
//         Get
//         Put
//     ]
// }
// 
// operation Delete {
//     input: Key
//     output: Unit
//     errors: [
//         KeyNotFoundError
//         UnauthorizedError
//     ]
// }
// 
// operation Get {
//     input: Key
//     output: Value
//     errors: [
//         KeyNotFoundError
//         UnauthorizedError
//     ]
// }
// 
// operation Put {
//     input: KeyValue
//     output: Unit
//     errors: [
//         UnauthorizedError
//     ]
// }
// 
// structure Key {
//     @required()
//     key: String
// }
// 
// @error("client")
// structure KeyNotFoundError {
//     @required()
//     message: String
// }
// ...