[http] Expose isKibanaReponse helper in public API (#182392)

For some other changes I'm working on, I need to be able to distinguish
if a route handler returned a `IKibanaResponse` / `KibanaResponse`
object or some other object that needs to be wrapped before being sent
back.

Rather than duplicating this little helper I want to expose it as part
of the public API of `core.http`.

packages/core/http/core-http-router-server-internal/index.ts

@@ -25,9 +25,4 @@ export type {
 export { isKibanaRequest, isRealRequest, ensureRawRequest, CoreKibanaRequest } from './src/request';
 export { isSafeMethod } from './src/route';
 export { HapiResponseAdapter } from './src/response_adapter';
-export {
-  kibanaResponseFactory,
-  lifecycleResponseFactory,
-  isKibanaResponse,
-  KibanaResponse,
-} from './src/response';
+export { kibanaResponseFactory, lifecycleResponseFactory, KibanaResponse } from './src/response';

packages/core/http/core-http-router-server-internal/src/response.ts

@@ -24,10 +24,6 @@ import type {
 } from '@kbn/core-http-server';
 import mime from 'mime';
 
-export function isKibanaResponse(response: Record<string, any>): response is IKibanaResponse {
-  return typeof response.status === 'number' && typeof response.options === 'object';
-}
-
 /**
  * A response data object, expected to returned as a result of {@link RequestHandler} execution
  * @internal

packages/core/http/core-http-server-internal/src/lifecycle/auth.ts

@@ -18,12 +18,12 @@ import type {
   AuthResultRedirected,
   AuthToolkit,
 } from '@kbn/core-http-server';
+import { isKibanaResponse } from '@kbn/core-http-server';
 import { AuthResultType } from '@kbn/core-http-server';
 import {
   HapiResponseAdapter,
   CoreKibanaRequest,
   lifecycleResponseFactory,
-  isKibanaResponse,
 } from '@kbn/core-http-router-server-internal';
 
 const authResult = {

packages/core/http/core-http-server-internal/src/lifecycle/on_post_auth.ts

@@ -14,12 +14,12 @@ import type {
   OnPostAuthResult,
   OnPostAuthHandler,
 } from '@kbn/core-http-server';
+import { isKibanaResponse } from '@kbn/core-http-server';
 import { OnPostAuthResultType } from '@kbn/core-http-server';
 import {
   HapiResponseAdapter,
   CoreKibanaRequest,
   lifecycleResponseFactory,
-  isKibanaResponse,
 } from '@kbn/core-http-router-server-internal';
 
 const postAuthResult = {

packages/core/http/core-http-server-internal/src/lifecycle/on_pre_auth.ts

@@ -14,11 +14,11 @@ import type {
   OnPreAuthHandler,
   OnPreAuthToolkit,
 } from '@kbn/core-http-server';
+import { isKibanaResponse } from '@kbn/core-http-server';
 import { OnPreAuthResultType } from '@kbn/core-http-server';
 import {
   HapiResponseAdapter,
   CoreKibanaRequest,
-  isKibanaResponse,
   lifecycleResponseFactory,
 } from '@kbn/core-http-router-server-internal';
 

packages/core/http/core-http-server-internal/src/lifecycle/on_pre_routing.ts

@@ -16,11 +16,11 @@ import type {
   OnPreRoutingResult,
   OnPreRoutingHandler,
 } from '@kbn/core-http-server';
+import { isKibanaResponse } from '@kbn/core-http-server';
 import { OnPreRoutingResultType } from '@kbn/core-http-server';
 import {
   HapiResponseAdapter,
   CoreKibanaRequest,
-  isKibanaResponse,
   lifecycleResponseFactory,
 } from '@kbn/core-http-router-server-internal';
 

packages/core/http/core-http-server/index.ts

@@ -112,6 +112,7 @@ export {
   getRequestValidation,
   getResponseValidation,
   isFullValidatorContainer,
+  isKibanaResponse,
 } from './src/router';
 
 export type { ICspConfig } from './src/csp';

packages/core/http/core-http-server/src/router/index.ts

@@ -42,6 +42,7 @@ export type {
   ErrorHttpResponseOptions,
   FileHttpResponseOptions,
 } from './response';
+export { isKibanaResponse } from './response';
 export type {
   RouteConfigOptions,
   RouteMethod,

packages/core/http/core-http-server/src/router/response.test.ts

@@ -0,0 +1,85 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+import { isKibanaResponse } from './response';
+
+describe('isKibanaResponse', () => {
+  it('expects the status to be a number', () => {
+    expect(
+      isKibanaResponse({
+        status: 200,
+        options: {},
+      })
+    ).toEqual(true);
+
+    expect(
+      isKibanaResponse({
+        status: '200',
+        options: {},
+      })
+    ).toEqual(false);
+  });
+
+  it('expects the options to be an object', () => {
+    expect(
+      isKibanaResponse({
+        status: 200,
+        options: {},
+      })
+    ).toEqual(true);
+
+    expect(
+      isKibanaResponse({
+        status: 200,
+        options: [],
+      })
+    ).toEqual(false);
+    expect(
+      isKibanaResponse({
+        status: 200,
+        options: null,
+      })
+    ).toEqual(false);
+    expect(
+      isKibanaResponse({
+        status: 200,
+        options: 'a string',
+      })
+    ).toEqual(false);
+    expect(
+      isKibanaResponse({
+        status: 200,
+        options: new Set(),
+      })
+    ).toEqual(false);
+    expect(
+      isKibanaResponse({
+        status: 200,
+        options: () => {},
+      })
+    ).toEqual(false);
+  });
+
+  it('allows a payload but no other properties', () => {
+    expect(
+      isKibanaResponse({
+        status: 200,
+        options: {},
+        payload: 'My stuff',
+      })
+    ).toEqual(true);
+
+    expect(
+      isKibanaResponse({
+        status: 200,
+        options: {},
+        data: 'Not allowed',
+      })
+    ).toEqual(false);
+  });
+});

packages/core/http/core-http-server/src/router/response.ts

@@ -55,6 +55,22 @@ export interface IKibanaResponse<T extends HttpResponsePayload | ResponseError =
   readonly options: HttpResponseOptions;
 }
 
+export function isKibanaResponse(response: Record<string, any>): response is IKibanaResponse {
+  const { status, options, payload, ...rest } = response;
+
+  if (Object.keys(rest).length !== 0) {
+    return false;
+  }
+
+  return (
+    typeof status === 'number' &&
+    typeof options === 'object' &&
+    !Array.isArray(options) &&
+    options !== null &&
+    !(options instanceof Set)
+  );
+}
+
 /**
  * HTTP response parameters for a response with adjustable status code.
  * @public