refactor(channels): dedupe transport and gateway test scaffolds

src/gateway/test-with-server.ts

@@ -0,0 +1,41 @@
+import { afterAll, beforeAll } from "vitest";
+import { startServerWithClient } from "./test-helpers.js";
+import { connectOk } from "./test-helpers.js";
+
+type StartServerWithClient = typeof startServerWithClient;
+export type GatewayWs = Awaited<ReturnType<StartServerWithClient>>["ws"];
+export type GatewayServer = Awaited<ReturnType<StartServerWithClient>>["server"];
+
+export async function withServer<T>(run: (ws: GatewayWs) => Promise<T>): Promise<T> {
+  const { server, ws, envSnapshot } = await startServerWithClient("secret");
+  try {
+    return await run(ws);
+  } finally {
+    ws.close();
+    await server.close();
+    envSnapshot.restore();
+  }
+}
+
+export function installConnectedControlUiServerSuite(
+  onReady: (started: { server: GatewayServer; ws: GatewayWs; port: number }) => void,
+): void {
+  let started: Awaited<ReturnType<StartServerWithClient>> | null = null;
+
+  beforeAll(async () => {
+    started = await startServerWithClient(undefined, { controlUiEnabled: true });
+    onReady({
+      server: started.server,
+      ws: started.ws,
+      port: started.port,
+    });
+    await connectOk(started.ws);
+  });
+
+  afterAll(async () => {
+    started?.ws.close();
+    if (started?.server) {
+      await started.server.close();
+    }
+  });
+}