Initial commit (by create-cloudflare CLI)

node_modules/wrangler/templates/middleware/loader-sw.ts

@@ -0,0 +1,228 @@
+import {
+	Awaitable,
+	Dispatcher,
+	IncomingRequest,
+	Middleware,
+	__facade_invoke__,
+	__facade_register__,
+	__facade_registerInternal__,
+} from "./common";
+export { __facade_register__, __facade_registerInternal__ };
+
+// Miniflare 2's `EventTarget` follows the spec and doesn't allow exceptions to
+// be caught by `dispatchEvent`. Instead it has a custom `ThrowingEventTarget`
+// class that rethrows errors from event listeners in `dispatchEvent`.
+// We'd like errors to be propagated to the top-level `addEventListener`, so
+// we'd like to use `ThrowingEventTarget`. Unfortunately, `ThrowingEventTarget`
+// isn't exposed on the global scope, but `WorkerGlobalScope` (which extends
+// `ThrowingEventTarget`) is. Therefore, we get at it in this nasty way.
+let __FACADE_EVENT_TARGET__: EventTarget;
+if ((globalThis as any).MINIFLARE) {
+	__FACADE_EVENT_TARGET__ = new (Object.getPrototypeOf(WorkerGlobalScope))();
+} else {
+	__FACADE_EVENT_TARGET__ = new EventTarget();
+}
+
+function __facade_isSpecialEvent__(
+	type: string
+): type is "fetch" | "scheduled" {
+	return type === "fetch" || type === "scheduled";
+}
+const __facade__originalAddEventListener__ = globalThis.addEventListener;
+const __facade__originalRemoveEventListener__ = globalThis.removeEventListener;
+const __facade__originalDispatchEvent__ = globalThis.dispatchEvent;
+
+globalThis.addEventListener = function (type, listener, options) {
+	if (__facade_isSpecialEvent__(type)) {
+		__FACADE_EVENT_TARGET__.addEventListener(
+			type,
+			listener as EventListenerOrEventListenerObject,
+			options
+		);
+	} else {
+		__facade__originalAddEventListener__(type, listener, options);
+	}
+};
+globalThis.removeEventListener = function (type, listener, options) {
+	if (__facade_isSpecialEvent__(type)) {
+		__FACADE_EVENT_TARGET__.removeEventListener(
+			type,
+			listener as EventListenerOrEventListenerObject,
+			options
+		);
+	} else {
+		__facade__originalRemoveEventListener__(type, listener, options);
+	}
+};
+globalThis.dispatchEvent = function (event) {
+	if (__facade_isSpecialEvent__(event.type)) {
+		return __FACADE_EVENT_TARGET__.dispatchEvent(event);
+	} else {
+		return __facade__originalDispatchEvent__(event);
+	}
+};
+
+declare global {
+	var addMiddleware: typeof __facade_register__;
+	var addMiddlewareInternal: typeof __facade_registerInternal__;
+}
+globalThis.addMiddleware = __facade_register__;
+globalThis.addMiddlewareInternal = __facade_registerInternal__;
+
+const __facade_waitUntil__ = Symbol("__facade_waitUntil__");
+const __facade_response__ = Symbol("__facade_response__");
+const __facade_dispatched__ = Symbol("__facade_dispatched__");
+
+class __Facade_ExtendableEvent__ extends Event {
+	[__facade_waitUntil__]: Awaitable<unknown>[] = [];
+
+	waitUntil(promise: Awaitable<any>) {
+		if (!(this instanceof __Facade_ExtendableEvent__)) {
+			throw new TypeError("Illegal invocation");
+		}
+		this[__facade_waitUntil__].push(promise);
+	}
+}
+
+interface FetchEventInit extends EventInit {
+	request: Request;
+	passThroughOnException: FetchEvent["passThroughOnException"];
+}
+
+class __Facade_FetchEvent__ extends __Facade_ExtendableEvent__ {
+	#request: Request;
+	#passThroughOnException: FetchEvent["passThroughOnException"];
+	[__facade_response__]?: Awaitable<Response>;
+	[__facade_dispatched__] = false;
+
+	constructor(type: "fetch", init: FetchEventInit) {
+		super(type);
+		this.#request = init.request;
+		this.#passThroughOnException = init.passThroughOnException;
+	}
+
+	get request() {
+		return this.#request;
+	}
+
+	respondWith(response: Awaitable<Response>) {
+		if (!(this instanceof __Facade_FetchEvent__)) {
+			throw new TypeError("Illegal invocation");
+		}
+		if (this[__facade_response__] !== undefined) {
+			throw new DOMException(
+				"FetchEvent.respondWith() has already been called; it can only be called once.",
+				"InvalidStateError"
+			);
+		}
+		if (this[__facade_dispatched__]) {
+			throw new DOMException(
+				"Too late to call FetchEvent.respondWith(). It must be called synchronously in the event handler.",
+				"InvalidStateError"
+			);
+		}
+		this.stopImmediatePropagation();
+		this[__facade_response__] = response;
+	}
+
+	passThroughOnException() {
+		if (!(this instanceof __Facade_FetchEvent__)) {
+			throw new TypeError("Illegal invocation");
+		}
+		// Need to call native method immediately in case uncaught error thrown
+		this.#passThroughOnException();
+	}
+}
+
+interface ScheduledEventInit extends EventInit {
+	scheduledTime: number;
+	cron: string;
+	noRetry: ScheduledEvent["noRetry"];
+}
+
+class __Facade_ScheduledEvent__ extends __Facade_ExtendableEvent__ {
+	#scheduledTime: number;
+	#cron: string;
+	#noRetry: ScheduledEvent["noRetry"];
+
+	constructor(type: "scheduled", init: ScheduledEventInit) {
+		super(type);
+		this.#scheduledTime = init.scheduledTime;
+		this.#cron = init.cron;
+		this.#noRetry = init.noRetry;
+	}
+
+	get scheduledTime() {
+		return this.#scheduledTime;
+	}
+
+	get cron() {
+		return this.#cron;
+	}
+
+	noRetry() {
+		if (!(this instanceof __Facade_ScheduledEvent__)) {
+			throw new TypeError("Illegal invocation");
+		}
+		// Need to call native method immediately in case uncaught error thrown
+		this.#noRetry();
+	}
+}
+
+__facade__originalAddEventListener__("fetch", (event) => {
+	const ctx: ExecutionContext = {
+		waitUntil: event.waitUntil.bind(event),
+		passThroughOnException: event.passThroughOnException.bind(event),
+	};
+
+	const __facade_sw_dispatch__: Dispatcher = function (type, init) {
+		if (type === "scheduled") {
+			const facadeEvent = new __Facade_ScheduledEvent__("scheduled", {
+				scheduledTime: Date.now(),
+				cron: init.cron ?? "",
+				noRetry() {},
+			});
+
+			__FACADE_EVENT_TARGET__.dispatchEvent(facadeEvent);
+			event.waitUntil(Promise.all(facadeEvent[__facade_waitUntil__]));
+		}
+	};
+
+	const __facade_sw_fetch__: Middleware = function (request, _env, ctx) {
+		const facadeEvent = new __Facade_FetchEvent__("fetch", {
+			request,
+			passThroughOnException: ctx.passThroughOnException,
+		});
+
+		__FACADE_EVENT_TARGET__.dispatchEvent(facadeEvent);
+		facadeEvent[__facade_dispatched__] = true;
+		event.waitUntil(Promise.all(facadeEvent[__facade_waitUntil__]));
+
+		const response = facadeEvent[__facade_response__];
+		if (response === undefined) {
+			throw new Error("No response!"); // TODO: proper error message
+		}
+		return response;
+	};
+
+	event.respondWith(
+		__facade_invoke__(
+			event.request as IncomingRequest,
+			globalThis,
+			ctx,
+			__facade_sw_dispatch__,
+			__facade_sw_fetch__
+		)
+	);
+});
+
+__facade__originalAddEventListener__("scheduled", (event) => {
+	const facadeEvent = new __Facade_ScheduledEvent__("scheduled", {
+		scheduledTime: event.scheduledTime,
+		cron: event.cron,
+		noRetry: event.noRetry.bind(event),
+	});
+
+	__FACADE_EVENT_TARGET__.dispatchEvent(facadeEvent);
+	event.waitUntil(Promise.all(facadeEvent[__facade_waitUntil__]));
+});