fix(type-safe-api): fix duplicate 200 response for operations with de…

…fault responses

OpenAPI generator treated "default" responses as responses with code 0, however parseOpenapi treats
default as 200. Adjust code generation to follow OpenAPI for backwards compatibility and to avoid
duplicate 200 responses. Note that this should be revisited such that code generation allows for
any response code other than those defined to be returned for the default response, rather than 0.

References #841

packages/type-safe-api/scripts/type-safe-api/generators/generate-next.ts

@@ -15,9 +15,11 @@ import _kebabCase from "lodash/kebabCase";
 import _orderBy from "lodash/orderBy";
 import _uniq from "lodash/uniq";
 import _uniqBy from "lodash/uniqBy";
+import _isEqual from "lodash/isEqual";
 import { OpenAPIV3 } from "openapi-types";
 import * as parseOpenapi from "parse-openapi";
 import { getOperationResponses } from "parse-openapi/dist/parser/getOperationResponses";
+import { getOperationResponse } from "parse-openapi/dist/parser/getOperationResponse";
 
 const TSAPI_WRITE_FILE_START = "###TSAPI_WRITE_FILE###";
 const TSAPI_WRITE_FILE_END = "###/TSAPI_WRITE_FILE###";
@@ -453,12 +455,24 @@ const buildData = (inSpec: OpenAPIV3.Document, metadata: any) => {
         // Add all response models to the response model imports
         responseModelImports.push(...responses.filter(r => r.export === "reference").map(r => r.type));
 
-        // parseOpenapi does not distinguish between returning an "any" or returning "void"
-        // We distinguish this by looking back each response in the spec, and checking whether it
-        // has content
+        const defaultResponse = resolveIfRef(spec, specOp.responses?.['default']);
+
         [...responses, ...op.results].forEach((response) => {
+          // Check whether this response is actually the "default" response.
+          if (response.code === 200 && defaultResponse && _isEqual(response, getOperationResponse(spec, defaultResponse, 200))) {
+            // For backwards compatibility with OpenAPI generator, we set the response code for the default response to 0.
+            // See: https://github.com/OpenAPITools/openapi-generator/blob/8f2676c5c2bcbcc41942307e5c8648cee38bcc44/modules/openapi-generator/src/main/java/org/openapitools/codegen/CodegenResponse.java#L622
+            // TODO: we should likely revisit this to make the handler wrappers more intuitive for the default response case, as
+            // the code 0 would actually need to be returned by the server for marshalling etc to work for the model associated with
+            // the default response.
+            response.code = 0;
+          }
+
           const matchingSpecResponse = specOp.responses[`${response.code}`];
 
+          // parseOpenapi does not distinguish between returning an "any" or returning "void"
+          // We distinguish this by looking back each response in the spec, and checking whether it
+          // has content
           if (matchingSpecResponse) {
             // Resolve the ref if necessary
             const specResponse = resolveIfRef(spec, matchingSpecResponse);

packages/type-safe-api/test/resources/specs/default-response.yaml

@@ -0,0 +1,51 @@
+openapi: 3.0.3
+info:
+  version: 1.0.0
+  title: My API
+  description: See https://github.com/aws/aws-pdk/issues/841
+paths:
+  /hello:
+    get:
+      operationId: sayHello
+      x-handler:
+        language: typescript
+      parameters:
+        - in: query
+          name: name
+          schema:
+            type: string
+          required: true
+      responses:
+        200:
+          description: Successful response
+          content:
+            'application/json':
+              schema:
+                $ref: '#/components/schemas/SayHelloResponseContent'
+        default:
+          description: An error due to the client not being authorized to access the resource
+          content:
+            'application/json':
+              schema:
+                $ref: '#/components/schemas/ServiceUnavailableErrorResponseContent'
+components:
+  schemas:
+    SayHelloResponseContent:
+      type: object
+      properties:
+        id:
+          $ref: '#/components/schemas/HelloId'
+        message:
+          type: string
+      required:
+        - message
+    HelloId:
+      type: string
+      format: uuid
+    ServiceUnavailableErrorResponseContent:
+      type: object
+      properties:
+        message:
+          type: string
+      required:
+        - message