fix issue with openapi error response examples

modules/openapi/src/software/amazon/smithy/openapi/fromsmithy/protocols/AlloyAbstractRestProtocol.scala

@@ -32,6 +32,7 @@ import software.amazon.smithy.openapi.model._
 import java.util
 import java.util.function.Function
 import scala.jdk.CollectionConverters._
+import software.amazon.smithy.model.traits.ExamplesTrait.Example
 
 /*
  * Copyright 2019 Amazon.com, Inc. or its affiliates. All Rights Reserved.
@@ -426,16 +427,49 @@ abstract class AlloyAbstractRestProtocol[T <: Trait]
     result.asScala
   }
 
+  private def reorganizeExampleTraits(
+      operation: OperationShape,
+      shape: StructureShape
+  ): Shape = {
+    val isErrorShape = shape.hasTrait(classOf[ErrorTrait])
+    val operationOrError =
+      if (isErrorShape) shape
+      else operation
+
+    val allExamples: List[Example] =
+      operation
+        .getTrait(classOf[ExamplesTrait])
+        .asScala
+        .toList
+        .flatMap(_.getExamples.asScala)
+    val allRelevantExamples: List[Example] =
+      // error response so only include examples that are matching to this error shape
+      if (isErrorShape)
+        allExamples
+          .filter(
+            _.getError().asScala.map(_.getShapeId).contains(shape.toShapeId)
+          )
+      // not an error response so no error examples should be included
+      else allExamples.filter(_.getError().isEmpty())
+    val newExamplesTraitBuilder = ExamplesTrait.builder()
+    allRelevantExamples.foreach { ex => newExamplesTraitBuilder.addExample(ex) }
+    val exTrait: Trait = newExamplesTraitBuilder.build()
+    val newShape: Shape =
+      (Shape.shapeToBuilder(operationOrError): AbstractShapeBuilder[_, _])
+        .addTrait(exTrait)
+        .build()
+
+    newShape
+  }
+
   private def updateResponsesMapWithResponseStatusAndObject(
       context: Context[T],
       bindingIndex: HttpBindingIndex,
       operation: OperationShape,
       shape: StructureShape,
       responses: util.Map[String, ResponseObject]
   ) = {
-    val operationOrError =
-      if (shape.hasTrait(classOf[ErrorTrait])) shape
-      else operation
+    val operationOrError = reorganizeExampleTraits(operation, shape)
     val statusCode = context.getOpenApiProtocol.getOperationResponseStatusCode(
       context,
       operationOrError

modules/openapi/src/software/amazon/smithy/openapi/fromsmithy/protocols/ExampleNode.scala

@@ -69,9 +69,11 @@ object ExampleNode {
       memberNames: List[String]
   ): ExampleNode = {
     val members: List[(String, Node)] = memberNames.flatMap(name =>
-      example.getOutput.asScala.flatMap(
-        _.getMember(name).asScala.map(name -> _)
-      )
+      example.getOutput.asScala
+        .orElse(example.getError.asScala.map(_.getContent))
+        .flatMap(
+          _.getMember(name).asScala.map(name -> _)
+        )
     )
     ExampleNode(example, members)
   }

modules/openapi/test/resources/foo.json

@@ -129,6 +129,79 @@
         }
       }
     },
+    "/test_errors": {
+      "post": {
+        "operationId": "TestErrorsInExamples",
+        "requestBody": {
+          "content": {
+            "application/json": {
+              "schema": {
+                "$ref": "#/components/schemas/TestErrorsInExamplesRequestContent"
+              },
+              "examples": {
+                "ONE": {
+                  "value": {
+                    "in": "testinput"
+                  }
+                },
+                "TWO": {
+                  "value": {
+                    "in": "testinputtwo"
+                  }
+                }
+              }
+            }
+          },
+          "required": true
+        },
+        "responses": {
+          "200": {
+            "description": "TestErrorsInExamples200response",
+            "content": {
+              "application/json": {
+                "schema": {
+                  "$ref": "#/components/schemas/TestErrorsInExamplesResponseContent"
+                },
+                "examples": {
+                  "ONE": {
+                    "value": {
+                      "out": "testoutput"
+                    }
+                  }
+                }
+              }
+            }
+          },
+          "404": {
+            "description": "NotFound404response",
+            "content": {
+              "application/json": {
+                "schema": {
+                  "$ref": "#/components/schemas/NotFoundResponseContent"
+                },
+                "examples": {
+                  "TWO": {
+                    "value": {
+                      "message": "Notfoundmessage"
+                    }
+                  }
+                }
+              }
+            }
+          },
+          "500": {
+            "description": "GeneralServerError500response",
+            "content": {
+              "application/json": {
+                "schema": {
+                  "$ref": "#/components/schemas/GeneralServerErrorResponseContent"
+                }
+              }
+            }
+          }
+        }
+      }
+    },
     "/values": {
       "get": {
         "operationId": "GetValues",
@@ -340,6 +413,17 @@
           }
         ]
       },
+      "NotFoundResponseContent": {
+        "type": "object",
+        "properties": {
+          "message": {
+            "type": "string"
+          }
+        },
+        "required": [
+          "message"
+        ]
+      },
       "SomeValue": {
         "oneOf": [
           {
@@ -352,6 +436,28 @@
             "format": "int32"
           }
         ]
+      },
+      "TestErrorsInExamplesRequestContent": {
+        "type": "object",
+        "properties": {
+          "in": {
+            "type": "string"
+          }
+        },
+        "required": [
+          "in"
+        ]
+      },
+      "TestErrorsInExamplesResponseContent": {
+        "type": "object",
+        "properties": {
+          "out": {
+            "type": "string"
+          }
+        },
+        "required": [
+          "out"
+        ]
       }
     }
   },

modules/openapi/test/resources/foo.smithy

@@ -1,3 +1,5 @@
+$version: "2"
+
 namespace foo
 
 use alloy#simpleRestJson
@@ -14,7 +16,7 @@ use alloy#dataExamples
 service HelloWorldService {
   version: "0.0.1",
   errors: [GeneralServerError],
-  operations: [Greet, GetUnion, GetValues]
+  operations: [Greet, GetUnion, GetValues, TestErrorsInExamples]
 }
 
 @externalDocumentation(
@@ -28,6 +30,49 @@ operation Greet {
   output: Greeting
 }
 
+@error("client")
+@httpError(404)
+structure NotFound {
+  @required
+  message: String
+}
+
+@examples([
+  {
+    title: "ONE"
+    input: {
+        in: "test input"
+    }
+    output: {
+        out: "test output"
+    }
+  }
+  {
+    title: "TWO"
+    input: {
+        in: "test input two"
+    }
+    error: {
+        shapeId: NotFound
+        content: {
+            message: "Not found message"
+        }
+    }
+  }
+])
+@http(method: "POST", uri: "/test_errors")
+operation TestErrorsInExamples {
+  input := {
+    @required
+    in: String
+  }
+  output := {
+    @required
+    out: String
+  }
+  errors: [NotFound]
+}
+
 @readonly
 @http(method: "GET", uri: "/default")
 operation GetUnion {