feat: improve http transport configuration (#10)

src/transport/http.js

@@ -1,38 +1,53 @@
-import * as Transport from "./api.js"
-import fetch from "@web-std/fetch"
+import * as Transport from "./api.js";
+import * as CAR from "./car.js";
 
 /**
  * @template T
- * @param {URL} url
+ * @param {object} options
+ * @param {typeof fetch} [options.fetch]
+ * @param {URL} options.url
+ * @param {string} [options.method]
  * @returns {Transport.Channel<T>}
  */
-export const open = url => new Channel({ url })
+export const open = ({ url, fetch  =  globalThis.fetch, method = 'POST', }) => {
+  if (typeof fetch === 'undefined') {
+    throw new TypeError(`ucanto HTTP transport got undefined \`fetch\`. Try passing in a \`fetch\` implementation explicitly.`)
+  }
+  return new Channel({ fetch, url, method });
+}
+
 class Channel {
   /**
    * @param {object} options
    * @param {URL} options.url
+   * @param {typeof fetch} options.fetch
+   * @param {string} [options.method]
    */
-  constructor({ url }) {
-    this.url = url
+  constructor({ url, fetch, method }) {
+    this.fetch = fetch;
+    this.method = method;
+    this.url = url;
   }
   /**
    * @param {Transport.HTTPRequest} request
    * @returns {Promise<Transport.HTTPResponse>}
    */
   async request({ headers, body }) {
-    const response = await fetch(this.url.href, {
+    const decodedBody = await CAR.decode({ headers, body });
+    const response = await this.fetch(this.url.href, {
       headers,
       body,
-    })
+      method: this.method
+    });
 
     const buffer = response.ok
       ? await response.arrayBuffer()
-      : HTTPError.throw("HTTP Request failed", response)
+      : HTTPError.throw("HTTP Request failed", response);
 
     return {
       headers: Object.fromEntries(response.headers.entries()),
       body: new Uint8Array(buffer),
-    }
+    };
   }
 }
 
@@ -50,16 +65,16 @@ class HTTPError extends Error {
    * @returns {never}
    */
   static throw(message, options) {
-    throw new this(message, options)
+    throw new this(message, options);
   }
   /**
    * @param {string} message
    * @param {Options} options
    */
   constructor(message, { url, status = 500, statusText = "Server error" }) {
-    super(message)
-    this.url = url
-    this.status = status
-    this.statusText = statusText
+    super(message);
+    this.url = url;
+    this.status = status;
+    this.statusText = statusText;
   }
 }

test/client.spec.js

@@ -6,6 +6,12 @@ import * as Packet from "../src/transport/packet.js"
 import { writeCAR, writeCBOR, importActors } from "./util.js"
 import { isLink } from "../src/transport/packet.js"
 import * as Service from "./service.js"
+import polyfillFetch from "@web-std/fetch";
+
+// in node <17.5.0, globalThis.fetch is not defined, so use polyfill
+// https://nodejs.org/api/globals.html#fetch
+const fetch =
+  typeof globalThis.fetch !== "undefined" ? globalThis.fetch : polyfillFetch;
 
 describe("delegation", () => {
   it("delegation can be transpcoded as ucan", async () => {
@@ -168,10 +174,10 @@ describe("invoke", () => {
     const { alice, web3Storage } = await importActors()
     /** @type {Client.ConnectionView<Service.Service>} */
     const connection = Client.connect({
-      channel: HTTP.open(new URL("about:blank")),
+      channel: HTTP.open({ url: new URL("about:blank"), fetch }),
       encoder: Transport.CAR,
       decoder: Transport.CBOR,
-    })
+    });
 
     const car = await writeCAR([await writeCBOR({ hello: "world " })])
     const add = Client.invoke({
@@ -214,10 +220,10 @@ describe("invoke", () => {
 
     /** @type {Client.ConnectionView<Service.Service>} */
     const connection = Client.connect({
-      channel: HTTP.open(new URL("about:blank")),
+      channel: HTTP.open({ url: new URL("about:blank"), fetch }),
       encoder: Transport.CAR,
       decoder: Transport.CBOR,
-    })
+    });
 
     const proof = await Client.delegate({
       issuer: alice,