feat(protocol-http): add reason to HttpResponse (#4772)

Adds `reason` property to HttpResponse, which is a simple message
explaining the status code. The property is optional, so adding it
is backward compatible. Http handlers were updated to populate this
property when constructing the HttpResponse, except for the Node http2
handler, because http2 doesn't support an equivalent.

Tests were added to Http handlers to make sure the property is populated
when available.

packages/fetch-http-handler/src/fetch-http-handler.spec.ts

@@ -290,6 +290,28 @@ describe(FetchHttpHandler.name, () => {
     expect(mockRequest.mock.calls[0][1]).not.toHaveProperty("signal");
   });
 
+  it("creates correct HTTPResponse object", async () => {
+    const mockResponse = {
+      headers: {
+        entries: jest.fn().mockReturnValue([["foo", "bar"]]),
+      },
+      blob: jest.fn().mockResolvedValue(new Blob(["FOO"])),
+      status: 200,
+      statusText: "foo",
+    };
+    const mockFetch = jest.fn().mockResolvedValue(mockResponse);
+    (global as any).fetch = mockFetch;
+
+    const fetchHttpHandler = new FetchHttpHandler();
+    const { response } = await fetchHttpHandler.handle({} as any, {});
+
+    expect(mockFetch.mock.calls.length).toBe(1);
+    expect(response.headers).toStrictEqual({ foo: "bar" });
+    expect(response.reason).toBe("foo");
+    expect(response.statusCode).toBe(200);
+    expect(await blobToText(response.body)).toBe("FOO");
+  });
+
   describe("#destroy", () => {
     it("should be callable and return nothing", () => {
       const httpHandler = new FetchHttpHandler();

packages/fetch-http-handler/src/fetch-http-handler.ts

@@ -91,6 +91,7 @@ export class FetchHttpHandler implements HttpHandler {
           return response.blob().then((body) => ({
             response: new HttpResponse({
               headers: transformedHeaders,
+              reason: response.statusText,
               statusCode: response.status,
               body,
             }),
@@ -100,6 +101,7 @@ export class FetchHttpHandler implements HttpHandler {
         return {
           response: new HttpResponse({
             headers: transformedHeaders,
+            reason: response.statusText,
             statusCode: response.status,
             body: response.body,
           }),

packages/node-http-handler/src/node-http-handler.spec.ts

@@ -141,6 +141,7 @@ describe("NodeHttpHandler", () => {
     it("can send http requests", async () => {
       const mockResponse = {
         statusCode: 200,
+        statusText: "OK",
         headers: {},
         body: "test",
       };
@@ -160,6 +161,7 @@ describe("NodeHttpHandler", () => {
       );
 
       expect(response.statusCode).toEqual(mockResponse.statusCode);
+      expect(response.reason).toEqual(mockResponse.statusText);
       expect(response.headers).toBeDefined();
       expect(response.headers).toMatchObject(mockResponse.headers);
       expect(response.body).toBeDefined();

packages/node-http-handler/src/node-http-handler.ts

@@ -134,6 +134,7 @@ export class NodeHttpHandler implements HttpHandler {
       const req = requestFunc(nodeHttpsOptions, (res) => {
         const httpResponse = new HttpResponse({
           statusCode: res.statusCode || -1,
+          reason: res.statusMessage,
           headers: getTransformedHeaders(res.headers),
           body: res,
         });

packages/protocol-http/src/httpResponse.ts

@@ -2,17 +2,20 @@ import { HeaderBag, HttpMessage, HttpResponse as IHttpResponse } from "@aws-sdk/
 
 type HttpResponseOptions = Partial<HttpMessage> & {
   statusCode: number;
+  reason?: string;
 };
 
 export interface HttpResponse extends IHttpResponse {}
 
 export class HttpResponse {
   public statusCode: number;
+  public reason?: string;
   public headers: HeaderBag;
   public body?: any;
 
   constructor(options: HttpResponseOptions) {
     this.statusCode = options.statusCode;
+    this.reason = options.reason;
     this.headers = options.headers || {};
     this.body = options.body;
   }

packages/types/src/http.ts

@@ -98,6 +98,7 @@ export interface HttpRequest extends HttpMessage, Endpoint {
  */
 export interface HttpResponse extends HttpMessage {
   statusCode: number;
+  reason?: string;
 }
 
 /**