feat(worker): add web streams support

Adds Web Streams API to worker context, and switches to the titelmedia fork of node-fetch which uses Web Streams instead of NodeJS ones. Also closes issue gja#39, as @titelmedia/node-fetch implements Response.redirect.

app/__tests__/worker_spec.js

@@ -1,7 +1,7 @@
 const express = require("express");
 const { Worker } = require("../worker");
 const { InMemoryKVStore } = require("../in-memory-kv-store");
-const { Headers } = require("node-fetch");
+const { Headers } = require("@titelmedia/node-fetch");
 
 describe("Workers", () => {
   test("It Can Create and Execute a Listener", () => {
@@ -103,6 +103,13 @@ describe("Workers", () => {
     expect(await response.text()).toBe("hello");
   });
 
+  test("It can return a redirect response", async () => {
+    const worker = new Worker("foo.com", 'addEventListener("fetch", (e) => e.respondWith(Response.redirect("http://bar.com", 302)))');
+    const response = await worker.executeFetchEvent("http://foo.com");
+    expect(response.status).toBe(302);
+    expect(response.headers.get("Location")).toBe("http://bar.com");
+  });
+
   describe("Cloudflare Headers", () => {
     it("Adds cloudflare headers", async () => {
       const worker = new Worker(

app/worker.js

@@ -1,12 +1,28 @@
 const { createContext, Script } = require("vm");
-const { Request, Response, Headers } = require("node-fetch");
+// The titelmedia node-fetch fork uses Web Streams instead of NodeJS ones
+const { Request, Response, Headers } = require("@titelmedia/node-fetch");
 const { URL } = require("url");
-const fetch = require("node-fetch");
+const fetch = require("@titelmedia/node-fetch");
 const atob = require("atob");
 const btoa = require("btoa");
 const crypto = new (require("node-webcrypto-ossl"))();
 const { TextDecoder, TextEncoder } = require("util");
 const { caches } = require("./caches");
+const {
+  ByteLengthQueuingStrategy,
+  CountQueuingStrategy,
+  ReadableByteStreamController,
+  ReadableStream,
+  ReadableStreamBYOBReader,
+  ReadableStreamBYOBRequest,
+  ReadableStreamDefaultController,
+  ReadableStreamDefaultReader,
+  TransformStream,
+  TransformStreamDefaultController,
+  WritableStream,
+  WritableStreamDefaultController,
+  WritableStreamDefaultWriter,
+} = require("web-streams-polyfill");
 
 function chomp(str) {
   return str.substr(0, str.length - 1);
@@ -106,7 +122,22 @@ class Worker {
       clearInterval,
 
       // Cache stubs
-      caches
+      caches,
+
+      // Streams
+      ByteLengthQueuingStrategy,
+      CountQueuingStrategy,
+      ReadableByteStreamController,
+      ReadableStream,
+      ReadableStreamBYOBReader,
+      ReadableStreamBYOBRequest,
+      ReadableStreamDefaultController,
+      ReadableStreamDefaultReader,
+      TransformStream,
+      TransformStreamDefaultController,
+      WritableStream,
+      WritableStreamDefaultController,
+      WritableStreamDefaultWriter
     };
     const script = new Script(workerContents);
     script.runInContext(

package.json

@@ -20,15 +20,16 @@
   "homepage": "https://github.com/gja/cloudflare-worker-local#readme",
   "dependencies": {
     "@iarna/toml": "^2.2.3",
+    "@titelmedia/node-fetch": "^3.1.1",
     "atob": "^2.1.2",
     "body-parser": "^1.18.3",
     "btoa": "^1.2.1",
     "express": "^4.16.4",
     "lodash.get": "^4.4.2",
     "lodash.merge": "^4.6.2",
     "mkdirp": "^1.0.4",
-    "node-fetch": "^2.3.0",
-    "node-webcrypto-ossl": "^1.0.48"
+    "node-webcrypto-ossl": "^1.0.48",
+    "web-streams-polyfill": "^3.0.1"
   },
   "optionalDependencies": {
     "minio": "^7.0.15"