Make zod parsing failures look more like real API 400s

oxide-openapi-gen-ts/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@oxide/openapi-gen-ts",
-  "version": "0.2.2",
+  "version": "0.3.0",
   "description": "OpenAPI client generator used to generate Oxide TypeScript SDK",
   "keywords": [
     "oxide",

oxide-openapi-gen-ts/src/client/msw-handlers.ts

@@ -90,10 +90,10 @@ export function generateMSWHandlers(spec: OpenAPIV3.Document, destDir: string) {
         ? `body: Json<Api.${bodyType}>,`
         : "";
     const pathParams = conf.parameters?.filter(
-      (param) => "name" in param && param.schema && param.in === "path"
+      (param) => "name" in param && param.schema && param.in === "path",
     );
     const queryParams = conf.parameters?.filter(
-      (param) => "name" in param && param.schema && param.in === "query"
+      (param) => "name" in param && param.schema && param.in === "query",
     );
     const pathParamsType = pathParams?.length
       ? `path: Api.${snakeToPascal(opId)}PathParams,`
@@ -133,9 +133,10 @@ export function generateMSWHandlers(spec: OpenAPIV3.Document, destDir: string) {
 
       // if any of the errors come from path params, just 404 — the resource cannot
       // exist if there's no valid name
-      const { issues } = result.error
-      const status = issues.some(e => e.path[0] === 'path') ? 404 : 400
-      return { paramsErr: json(issues, { status }) }
+      const status = result.error.issues.some((e) => e.path[0] === 'path') ? 404 : 400
+      const error_code = status === 404 ? 'NotFound' : 'InvalidRequest'
+      const message = 'Zod error for params: ' + JSON.stringify(result.error)
+      return { paramsErr: json({ error_code, message }, { status }) }
     }
 
     const handler = (handler: MSWHandlers[keyof MSWHandlers], paramSchema: ZodSchema | null, bodySchema: ZodSchema | null) => 
@@ -151,15 +152,18 @@ export function generateMSWHandlers(spec: OpenAPIV3.Document, destDir: string) {
         const { params, paramsErr } = paramSchema
           ? validateParams(paramSchema, req, pathParams)
           : { params: {}, paramsErr: undefined };
-        if (paramsErr) return json(paramsErr, { status: 400 });
+        if (paramsErr) return paramsErr;
 
         const { path, query } = params
 
         let body = undefined
         if (bodySchema) {
           const rawBody = await req.json()
           const result = bodySchema.transform(snakeify).safeParse(rawBody);
-          if (!result.success) return json(result.error.issues, { status: 400 })
+          if (!result.success) {
+            const message = 'Zod error for body: ' + JSON.stringify(result.error)
+            return json({ error_code: 'InvalidRequest', message }, { status: 400 })
+          }
           body = result.data
         }
 
@@ -172,9 +176,6 @@ export function generateMSWHandlers(spec: OpenAPIV3.Document, destDir: string) {
           if (typeof result === "number") {
             return new HttpResponse(null, { status: result });
           }
-          if (typeof result === "function") {
-            return result();
-          }
           if (result instanceof Response) {
             return result;
           }
@@ -183,17 +184,23 @@ export function generateMSWHandlers(spec: OpenAPIV3.Document, destDir: string) {
           if (typeof thrown === 'number') {
             return new HttpResponse(null, { status: thrown });
           } 
-          if (typeof thrown === "function") {
-            return thrown();
-          }
           if (typeof thrown === "string") {
             return json({ message: thrown }, { status: 400 });
           }
           if (thrown instanceof Response) {
             return thrown;
           }
+
+          // if it's not one of those, then we don't know what to do with it
           console.error('Unexpected mock error', thrown)
-          return json({ message: "Unknown Server Error" }, { status: 500 });
+          if (typeof thrown === 'function') {
+            console.error(
+              "It looks like you've accidentally thrown an error constructor function from a mock handler without calling it!"
+            )
+          }
+          // rethrow so everything breaks because this isn't supposed to happen
+          throw thrown
+
         }
       }
 
@@ -215,8 +222,8 @@ export function generateMSWHandlers(spec: OpenAPIV3.Document, destDir: string) {
 
     w(
       `http.${method}('${formatPath(
-        path
-      )}', handler(handlers['${handler}'], ${paramSchema}, ${bodySchema})),`
+        path,
+      )}', handler(handlers['${handler}'], ${paramSchema}, ${bodySchema})),`,
     );
   }
   w(`]}`);