response is backed

packages/http-client/package.json

@@ -15,6 +15,7 @@
   "license": "ISC",
   "dependencies": {
     "@foxify/events": "^2.1.0",
+    "@ollierelph/sensible-fetch": "workspace:*",
     "@ollierelph/result4t": "^0.3.0"
   },
   "devDependencies": {

packages/http-client/src/ImmutableHeaders.ts

@@ -3,11 +3,13 @@ import { Headers, SpecIterableIterator, SpecIterator } from "undici";
 export class ImmutableHeaders implements Readonly<Headers> {
   readonly #headers: Headers;
 
-  constructor(nextHeaders?: Headers | Record<string, string>) {
+  constructor(nextHeaders?: Headers | Record<string, string> | null) {
     this.#headers =
       nextHeaders instanceof Headers
         ? nextHeaders
-        : new Headers(nextHeaders) ?? new Headers();
+        : nextHeaders
+        ? new Headers(nextHeaders)
+        : new Headers();
   }
 
   append(name: string, value: string) {

packages/http-client/src/ImmutableResponse.ts

@@ -1,13 +1,138 @@
+import { IncomingHttpResponse } from "@ollierelph/sensible-fetch";
 import { ImmutableHeaders } from "~/src/ImmutableHeaders";
+import { ImmutableURL } from "~/src/ImmutableURL";
 
-export class ImmutableResponse {
-  constructor(
-    public status: number,
-    private body: unknown,
-    public headers: ImmutableHeaders = new ImmutableHeaders(),
-  ) {}
+type StatusCode =
+  | 100
+  | 101
+  | 102
+  | 103
+  | 200
+  | 201
+  | 202
+  | 203
+  | 204
+  | 205
+  | 206
+  | 207
+  | 208
+  | 218
+  | 226
+  | 300
+  | 301
+  | 302
+  | 303
+  | 304
+  | 306
+  | 307
+  | 308
+  | 400
+  | 401
+  | 402
+  | 403
+  | 404
+  | 405
+  | 406
+  | 407
+  | 408
+  | 409
+  | 410
+  | 411
+  | 412
+  | 413
+  | 414
+  | 415
+  | 416
+  | 417
+  | 418
+  | 419
+  | 420
+  | 421
+  | 422
+  | 423
+  | 424
+  | 426
+  | 428
+  | 429
+  | 431
+  | 440
+  | 444
+  | 449
+  | 450
+  | 451
+  | 494
+  | 495
+  | 496
+  | 497
+  | 498
+  | 499
+  | 500
+  | 501
+  | 502
+  | 503
+  | 504
+  | 505
+  | 506
+  | 507
+  | 508
+  | 509
+  | 510
+  | 511
+  | 520
+  | 521
+  | 522
+  | 523
+  | 524
+  | 525
+  | 526
+  | 527
+  | 530
+  | 598;
+
+export class ImmutableResponse<Status extends StatusCode>
+  implements Readonly<IncomingHttpResponse<ImmutableURL, Status>>
+{
+  #response: IncomingHttpResponse;
+  #status: Status;
+  protected constructor(status: Status, response: IncomingHttpResponse) {
+    this.#status = status;
+    this.#response = response;
+  }
+
+  fromResponse(response: IncomingHttpResponse) {
+    return new ImmutableResponse(response.status as StatusCode, response);
+  }
+
+  get status() {
+    return this.#status;
+  }
+  get statusText() {
+    return this.#response.statusText;
+  }
+  get type() {
+    return this.#response.type;
+  }
+  get url() {
+    return new ImmutableURL(this.#response.url);
+  }
+  get body() {
+    return this.#response.body;
+  }
+  get headers() {
+    return new ImmutableHeaders(this.#response.headers);
+  }
 
   json(): Promise<unknown> {
-    return Promise.resolve(this.body);
+    return this.clone().json();
+  }
+  blob(): Promise<Blob> {
+    return this.clone().blob();
+  }
+  text(): Promise<string> {
+    return this.clone().text();
+  }
+
+  clone() {
+    return new ImmutableResponse(this.status, this.#response);
   }
 }

packages/sensible-fetch/src/index.ts

@@ -140,9 +140,12 @@ export interface HttpFormData {
   readonly [Symbol.iterator]: () => SpecIterator<[string, string]>;
 }
 
-export interface IncomingHttpResponse {
-  readonly url: string;
-  readonly status: number;
+/**
+ * An approximation of Response
+ */
+export interface IncomingHttpResponse<URL = string, Status = number> {
+  readonly url: URL;
+  readonly status: Status;
   readonly statusText: string;
   readonly type:
     | "default"
@@ -153,7 +156,7 @@ export interface IncomingHttpResponse {
     | "opaqueredirect";
   readonly body: ReadableStream | null;
   readonly headers: Headers | null;
-  clone(): IncomingHttpResponse;
+  clone(): IncomingHttpResponse<URL, Status>;
   json(): Promise<unknown>;
   text(): Promise<string>;
   blob(): Promise<Blob>;