[breadboard/remote] Add proxy end-to-end test.

seeds/breadboard/tests/helpers/_test-kit.ts

@@ -66,4 +66,16 @@ export const TestKit = new KitBuilder({
 
     return await runnableBoard.runOnce(args, context);
   },
+  /**
+   * Reverses provided string inputs. Will crash if provided non-string inputs.
+   * @param inputs InputValues
+   */
+  reverser: async (inputs) => {
+    return Object.fromEntries(
+      Object.entries(inputs).map(([key, value]) => [
+        key,
+        (inputs[key] = [...(value as string)].reverse().join("")),
+      ])
+    );
+  },
 });

seeds/breadboard/tests/remote/proxy.ts

@@ -0,0 +1,69 @@
+/**
+ * @license
+ * Copyright 2023 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import test from "ava";
+import { MockHTTPConnection } from "../helpers/_test-transport.js";
+import { ProxyClient, ProxyServer } from "../../src/remote/proxy.js";
+import {
+  HTTPClientTransport,
+  HTTPServerTransport,
+} from "../../src/remote/http.js";
+import {
+  AnyProxyRequestMessage,
+  AnyProxyResponseMessage,
+} from "../../src/remote/protocol.js";
+import { Board } from "../../src/board.js";
+import { TestKit } from "../helpers/_test-kit.js";
+
+test("ProxyServer can use HTTPServerTransport", async (t) => {
+  const board = new Board();
+  board.addKit(TestKit);
+
+  const request = {
+    body: [
+      "proxy",
+      { node: { id: "id", type: "noop" }, inputs: { hello: "world" } },
+    ] as AnyProxyRequestMessage,
+  };
+  const response = {
+    write: (response: unknown) => {
+      const data = JSON.parse(response as string);
+      t.deepEqual(data, ["proxy", { outputs: { hello: "world" } }]);
+      return true;
+    },
+    end: () => {
+      t.pass();
+    },
+  };
+  const transport = new HTTPServerTransport(request, response);
+  const server = new ProxyServer(transport);
+  await server.serve(board);
+});
+
+test("End-to-end proxy works with HTTP transports", async (t) => {
+  const connection = new MockHTTPConnection<AnyProxyRequestMessage>();
+  connection.onRequest(async (request, response) => {
+    const serverBoard = new Board();
+    serverBoard.addKit(TestKit);
+
+    const serverTransport = new HTTPServerTransport<
+      AnyProxyRequestMessage,
+      AnyProxyResponseMessage
+    >(request, response);
+    const server = new ProxyServer(serverTransport);
+    await server.serve(serverBoard);
+  });
+  const clientTransport = new HTTPClientTransport<
+    AnyProxyRequestMessage,
+    AnyProxyResponseMessage
+  >("http://example.com", { fetch: connection.fetch });
+  const client = new ProxyClient(clientTransport);
+  const result = await client.proxy(
+    { id: "id", type: "reverser" },
+    { hello: "world" }
+  );
+  t.deepEqual(result, { hello: "dlrow" });
+});