feat(ext/fetch): fetch method (WIP)

feat(ext/fetch): fetch method

Author: load1n9

examples/fetch.ts

@@ -0,0 +1,10 @@
+const foo = async () => {
+  try {
+    const res = await fetch("https://developer.mozilla.org");
+    console.log(res);
+  } catch (e) {
+    console.error(e);
+  }
+};
+
+foo();

runtime/src/ext/fetch/fetch/mod.ts

@@ -0,0 +1,99 @@
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at https://mozilla.org/MPL/2.0/.
+
+/**
+ * Implementation of the fetch API for Andromeda
+ * Based on: https://developer.mozilla.org/ja/docs/Web/API/Window/fetch
+ * Spec: https://fetch.spec.whatwg.org/#fetch-method/
+ */
+
+type RequestInfo = Request | URL;
+
+/** The fetch(input, init) method steps are: */
+const fetch = (input: RequestInfo, init = undefined) => {
+  // 1. Let p be a new promise.
+  let p = createDeferredPromise();
+
+  // 2. Let requestObject be the result of invoking the initial value
+  // of Request as constructor with input and init as arguments.
+  // If this throws an exception, reject p with it and return p.
+  let request: any;
+
+  try {
+    // 3. Let request be requestObject’s request.
+    // @ts-ignore deno lint stuff
+    request = new Request(input, init);
+  } catch (e) {
+    p.reject(e);
+    return p.promise;
+  }
+
+  // 4. If requestObject’s signal is aborted, then:
+  // if (request.signal.aborted) {
+  // 1. Abort the fetch() call with p, request, null, and
+  // requestObject’s signal’s abort reason.
+  //
+  // TODO: abortFetch
+  //
+  // 2. Return p.
+  // return p.promise;
+  // }
+
+  // 5. Let globalObject be request’s client’s global object.
+  // const globalObject = request.client.globalObject;
+
+  // 6. If globalObject is a ServiceWorkerGlobalScope object,
+  // then set request’s service-workers mode to "none".
+  // if (globalObject?.constructor?.name === "ServiceWorkerGlobalScope") {
+  //   request.serviceWorkers = "none";
+  // }
+
+  // 7. Let responseObject be null.
+  let responseObject = null;
+
+  // 8. Let relevantRealm be this’s relevant realm.
+  // 9. Let locallyAborted be false.
+  // NOTE: This lets us reject promises with predictable timing,
+  // when the request to abort comes from the same thread as
+  // the call to fetch.
+  let locallyAborted = false;
+
+  // 10. Let controller be null.
+  let controller = null;
+
+  // TODO: abort controller
+  // 11. Add the following abort steps to requestObject’s signal:
+  //  1. Set locallyAborted to true.
+  //  2. Assert: controller is non-null.
+  //  3. Abort controller with requestObject’s signal’s abort reason.
+  //  4. Abort the fetch() call with p, request, responseObject,
+  //     and requestObject’s signal’s abort reason.
+
+  // 12. Set controller to the result of calling fetch given request
+  //     and processResponse given response being these steps:
+  //  1. If locallyAborted is true, then abort these steps.
+  //  2. If response’s aborted flag is set, then:
+  //    1. Let deserializedError be the result of deserialize a serialized abort reason given controller’s serialized abort reason and relevantRealm.
+  //    2. Abort the fetch() call with p, request, responseObject, and deserializedError.
+  //    3. Abort these steps.
+  //  3. If response is a network error, then reject p with a TypeError and abort these steps.
+  //  4. Set responseObject to the result of creating a Response object, given response, "immutable", and relevantRealm.
+  //  5. Resolve p with responseObject.
+
+  // 13. Return p.
+  return p;
+};
+
+(globalThis as unknown as { fetch: typeof fetch }).fetch = fetch;
+
+function createDeferredPromise() {
+  let res: any;
+  let rej: any;
+  const promise = new Promise((resolve, reject) => {
+    res = resolve;
+    rej = reject;
+  });
+
+  return { promise, resolve: res, reject: rej };
+}

runtime/src/ext/fetch/mod.rs

@@ -6,6 +6,21 @@ mod headers;
 mod request;
 mod response;
 
+use andromeda_core::Extension;
 pub use headers::*;
 pub use request::*;
 pub use response::*;
+
+#[derive(Default)]
+pub struct FetchExt;
+
+impl FetchExt {
+    pub fn new_extension() -> Extension {
+        Extension {
+            name: "fetch",
+            ops: vec![],
+            storage: None,
+            files: vec![include_str!("./fetch/mod.ts")],
+        }
+    }
+}

runtime/src/ext/fetch/request/mod.ts

@@ -103,7 +103,10 @@ class Request {
   [bodySymbol]: any = null;
 
   /** https://fetch.spec.whatwg.org/#request-class */
-  constructor(input: RequestInfo, init: RequestInit = { __proto__: null } as any) {
+  constructor(
+    input: RequestInfo,
+    init: RequestInit = { __proto__: null } as any,
+  ) {
     // 1. Let request be null.
     let request: any = null;
 
@@ -396,13 +399,6 @@ class Request {
     // 42. Set this’s request’s body to finalBody.
     request.body = finalBody;
 
-    const url = request.url;
-    console.log("url", url);
-    const method = request.method;
-    console.log("method", method);
-    const credentials = request.credentials;
-    console.log("credentials", credentials);
-
     this[requestSymbol] = request;
   }
 

runtime/src/ext/local_storage/mod.rs

@@ -131,7 +131,7 @@ impl LocalStorageExt {
         args: ArgumentsList,
         gc: GcScope<'gc, '_>,
     ) -> JsResult<'gc, Value<'gc>> {
-        let persistent = if args.len() > 0 {
+        let persistent = if !args.is_empty() {
             match args.get(0) {
                 Value::Boolean(b) => b,
                 _ => true, // default to localStorage

runtime/src/recommended.rs

@@ -8,6 +8,7 @@ use nova_vm::ecmascript::execution::agent::{GcAgent, RealmRoot};
 use crate::{
     //BroadcastChannelExt,
     ConsoleExt,
+    FetchExt,
     FsExt,
     HeadersExt,
     ProcessExt,
@@ -31,6 +32,7 @@ pub fn recommended_extensions() -> Vec<Extension> {
         // BroadcastChannelExt::new_extension(),
         RequestExt::new_extension(),
         ResponseExt::new_extension(),
+        FetchExt::new_extension(),
         #[cfg(feature = "canvas")]
         crate::CanvasExt::new_extension(),
         #[cfg(feature = "crypto")]