fix for discriminated union transform

modules/openapi/src/alloy/openapi/AlloyOpenApiExtension.scala

@@ -49,7 +49,8 @@ final class AlloyOpenApiExtension() extends Smithy2OpenApiExtension {
     new UntaggedUnions(),
     new DataExamplesMapper(),
     new ExternalDocumentationMapperJsonSchema(),
-    new NullableMapper()
+    new NullableMapper(),
+    new DiscriminatedUnionShapeId()
   ).asJava
 
 }

modules/openapi/src/alloy/openapi/DiscriminatedUnionMemberComponents.scala

@@ -40,11 +40,20 @@ class DiscriminatedUnionMemberComponents() extends OpenApiMapper {
       .getModel()
       .getUnionShapesWithTrait(classOf[DiscriminatedUnionTrait])
     val componentBuilder = openapi.getComponents().toBuilder()
-    val componentSchemas: Map[String, Schema] = openapi
+    val componentSchemas: Map[ShapeId, Schema] = openapi
       .getComponents()
       .getSchemas()
       .asScala
       .toMap
+      .flatMap { case (_, schema) =>
+        schema
+          .getExtension(DiscriminatedUnionShapeId.SHAPE_ID_KEY)
+          .asScala
+          .flatMap { node =>
+            node.toNode.asStringNode.asScala
+              .map(s => ShapeId.from(s.getValue) -> schema)
+          }
+      }
     unions.asScala.foreach { union =>
       val unionMixinName = union.getId().getName() + "Mixin"
       val unionMixinId =
@@ -82,19 +91,19 @@ class DiscriminatedUnionMemberComponents() extends OpenApiMapper {
         componentBuilder.putSchema(syntheticMemberName, syntheticUnionMember)
       }
 
-      val existingSchemaBuilder = componentSchemas
-        .get(union.toShapeId.getName)
-        .map(_.toBuilder())
-        .getOrElse(Schema.builder())
-      componentBuilder.putSchema(
-        union.toShapeId.getName,
-        updateDiscriminatedUnion(
-          union,
-          existingSchemaBuilder,
-          discriminatorField
-        )
-          .build()
-      )
+      componentSchemas.get(union.toShapeId).foreach { sch =>
+        if (!sch.getOneOf.isEmpty) {
+          componentBuilder.putSchema(
+            union.toShapeId.getName,
+            updateDiscriminatedUnion(
+              union,
+              sch.toBuilder(),
+              discriminatorField
+            )
+              .build()
+          )
+        }
+      }
 
     }
     openapi.toBuilder.components(componentBuilder.build()).build()
@@ -130,6 +139,7 @@ class DiscriminatedUnionMemberComponents() extends OpenApiMapper {
         .asJava
     )
     schemaBuilder
+      .removeExtension(DiscriminatedUnionShapeId.SHAPE_ID_KEY)
       .oneOf(schemas)
       .putExtension(
         "discriminator",

modules/openapi/src/alloy/openapi/DiscriminatedUnionShapeId.scala

@@ -0,0 +1,44 @@
+/* Copyright 2022 Disney Streaming
+ *
+ * Licensed under the Tomorrow Open Source Technology License, Version 1.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    https://disneystreaming.github.io/TOST-1.0.txt
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package alloy.openapi
+
+import _root_.software.amazon.smithy.jsonschema.JsonSchemaConfig
+import _root_.software.amazon.smithy.jsonschema.JsonSchemaMapper
+import _root_.software.amazon.smithy.jsonschema.Schema.Builder
+import _root_.software.amazon.smithy.model.shapes.Shape
+import alloy.DiscriminatedUnionTrait
+
+import software.amazon.smithy.model.node.Node
+
+class DiscriminatedUnionShapeId() extends JsonSchemaMapper {
+
+  import DiscriminatedUnionShapeId._
+
+  override def updateSchema(
+      shape: Shape,
+      schemaBuilder: Builder,
+      config: JsonSchemaConfig
+  ): Builder = if (shape.hasTrait(classOf[DiscriminatedUnionTrait])) {
+    schemaBuilder.putExtension(
+      SHAPE_ID_KEY,
+      Node.from(shape.toShapeId.toString)
+    )
+  } else schemaBuilder
+}
+
+object DiscriminatedUnionShapeId {
+  private[openapi] val SHAPE_ID_KEY: String = "SHAPE_ID"
+}

modules/openapi/test/resources/bar.json

@@ -0,0 +1,67 @@
+{
+  "openapi": "3.0.2",
+  "info": {
+    "title": "BarService",
+    "version": ""
+  },
+  "paths": {
+    "/bar": {
+      "get": {
+        "operationId": "BarOp",
+        "responses": {
+          "200": {
+            "description": "BarOp200response",
+            "content": {
+              "application/json": {
+                "schema": {
+                  "$ref": "#/components/schemas/BarOpResponseContent"
+                }
+              }
+            }
+          }
+        }
+      }
+    }
+  },
+  "components": {
+    "schemas": {
+      "BarOpResponseContent": {
+        "type": "object",
+        "properties": {
+          "out": {
+            "$ref": "#/components/schemas/CatOrDog"
+          }
+        }
+      },
+      "CatOrDog": {
+        "oneOf": [
+          {
+            "type": "object",
+            "title": "one",
+            "properties": {
+              "one": {
+                "type": "string"
+              }
+            },
+            "required": [
+              "one"
+            ]
+          },
+          {
+            "type": "object",
+            "title": "two",
+            "properties": {
+              "two": {
+                "type": "integer",
+                "format": "int32"
+              }
+            },
+            "required": [
+              "two"
+            ]
+          }
+        ]
+      }
+    }
+  }
+}

modules/openapi/test/resources/bar.smithy

@@ -0,0 +1,22 @@
+$version: "2"
+
+namespace bar
+
+use alloy#simpleRestJson
+
+@simpleRestJson
+service BarService {
+    operations: [BarOp]
+}
+
+@http(method: "GET", uri: "/bar")
+operation BarOp {
+    output := {
+        out: CatOrDog
+    }
+}
+
+union CatOrDog {
+    one: String
+    two: Integer
+}

modules/openapi/test/src/alloy/openapi/OpenApiConversionSpec.scala

@@ -48,6 +48,30 @@ final class OpenApiConversionSpec extends munit.FunSuite {
     assertEquals(result, expected)
   }
 
+  test(
+    "OpenAPI conversion from alloy#simpleRestJson protocol with multiple namespaces"
+  ) {
+    val model = Model
+      .assembler()
+      .addImport(getClass().getClassLoader().getResource("foo.smithy"))
+      .addImport(getClass().getClassLoader().getResource("bar.smithy"))
+      .discoverModels()
+      .assemble()
+      .unwrap()
+
+    val result = convert(model, Some(Set("bar")))
+      .map(_.contents)
+      .mkString
+      .filterNot(_.isWhitespace)
+
+    val expected = Using
+      .resource(Source.fromResource("bar.json"))(
+        _.getLines().mkString.filterNot(_.isWhitespace)
+      )
+
+    assertEquals(result, expected)
+  }
+
   test("OpenAPI conversion from testJson protocol") {
     val model = Model
       .assembler()