Fetch: align IDL testing with other standards

See whatwg/fetch#719.

fetch/api/idl.any.js

@@ -0,0 +1,18 @@
+// META: global=window,worker
+// META: script=/resources/WebIDLParser.js
+// META: script=/resources/idlharness.js
+
+promise_test(async() => {
+  const text = await (await fetch("/interfaces/fetch.idl")).text();
+  const idl_array = new IdlArray();
+  idl_array.add_idls(text);
+  idl_array.add_untested_idls("[Exposed=(Window,Worker)] interface AbortSignal {};");
+  idl_array.add_untested_idls("[Exposed=(Window,Worker)] interface ReadableStream {};");
+  idl_array.add_untested_idls("enum ReferrerPolicy {};");
+  idl_array.add_objects({
+    Headers: ["new Headers()"],
+    Request: ["new Request('about:blank')"],
+    Response: ["new Response()"],
+  });
+  idl_array.test();
+}, "Fetch Standard IDL");

interfaces/fetch.idl

@@ -0,0 +1,97 @@
+typedef (sequence<sequence<ByteString>> or record<ByteString, ByteString>) HeadersInit;
+
+[Constructor(optional HeadersInit init),
+ Exposed=(Window,Worker)]
+interface Headers {
+  void append(ByteString name, ByteString value);
+  void delete(ByteString name);
+  ByteString? get(ByteString name);
+  boolean has(ByteString name);
+  void set(ByteString name, ByteString value);
+  iterable<ByteString, ByteString>;
+};
+typedef (Blob or BufferSource or FormData or URLSearchParams or ReadableStream or USVString) BodyInit;
+interface mixin Body {
+  readonly attribute ReadableStream? body;
+  readonly attribute boolean bodyUsed;
+  [NewObject] Promise<ArrayBuffer> arrayBuffer();
+  [NewObject] Promise<Blob> blob();
+  [NewObject] Promise<FormData> formData();
+  [NewObject] Promise<any> json();
+  [NewObject] Promise<USVString> text();
+};
+typedef (Request or USVString) RequestInfo;
+
+[Constructor(RequestInfo input, optional RequestInit init),
+ Exposed=(Window,Worker)]
+interface Request {
+  readonly attribute ByteString method;
+  readonly attribute USVString url;
+  [SameObject] readonly attribute Headers headers;
+
+  readonly attribute RequestDestination destination;
+  readonly attribute USVString referrer;
+  readonly attribute ReferrerPolicy referrerPolicy;
+  readonly attribute RequestMode mode;
+  readonly attribute RequestCredentials credentials;
+  readonly attribute RequestCache cache;
+  readonly attribute RequestRedirect redirect;
+  readonly attribute DOMString integrity;
+  readonly attribute boolean keepalive;
+  readonly attribute boolean isReloadNavigation;
+  readonly attribute AbortSignal signal;
+
+  [NewObject] Request clone();
+};
+Request includes Body;
+
+dictionary RequestInit {
+  ByteString method;
+  HeadersInit headers;
+  BodyInit? body;
+  USVString referrer;
+  ReferrerPolicy referrerPolicy;
+  RequestMode mode;
+  RequestCredentials credentials;
+  RequestCache cache;
+  RequestRedirect redirect;
+  DOMString integrity;
+  boolean keepalive;
+  AbortSignal? signal;
+  any window; // can only be set to null
+};
+
+enum RequestDestination { "", "audio", "audioworklet", "document", "embed", "font", "image", "manifest", "object", "paintworklet", "report", "script", "sharedworker", "style",  "track", "video", "worker", "xslt" };
+enum RequestMode { "navigate", "same-origin", "no-cors", "cors" };
+enum RequestCredentials { "omit", "same-origin", "include" };
+enum RequestCache { "default", "no-store", "reload", "no-cache", "force-cache", "only-if-cached" };
+enum RequestRedirect { "follow", "error", "manual" };
+[Constructor(optional BodyInit? body = null, optional ResponseInit init), Exposed=(Window,Worker)]
+interface Response {
+  [NewObject] static Response error();
+  [NewObject] static Response redirect(USVString url, optional unsigned short status = 302);
+
+  readonly attribute ResponseType type;
+
+  readonly attribute USVString url;
+  readonly attribute boolean redirected;
+  readonly attribute unsigned short status;
+  readonly attribute boolean ok;
+  readonly attribute ByteString statusText;
+  [SameObject] readonly attribute Headers headers;
+  readonly attribute Promise<Headers> trailer;
+
+  [NewObject] Response clone();
+};
+Response includes Body;
+
+dictionary ResponseInit {
+  unsigned short status = 200;
+  ByteString statusText = "OK";
+  HeadersInit headers;
+};
+
+enum ResponseType { "basic", "cors", "default", "error", "opaque", "opaqueredirect" };
+partial interface mixin WindowOrWorkerGlobalScope {
+  [NewObject] Promise<Response> fetch(RequestInfo input, optional RequestInit init);
+};