fix(custom-widgets): address v2 merge review (#6446)

e2e/shared/mock-api-server.ts

@@ -0,0 +1,50 @@
+import { createServer } from "node:http";
+import { getContainerRuntimeClient, TestContainers } from "testcontainers";
+
+import type { Server } from "node:http";
+
+const TESTCONTAINERS_SSHD_LABEL = "org.testcontainers.sshd";
+
+export interface MockApiServer {
+  url: string;
+  close: () => Promise<void>;
+}
+
+export async function startMockApiServerAsync(responseBody: unknown): Promise<MockApiServer> {
+  const body = JSON.stringify(responseBody);
+  const server: Server = await new Promise((resolve) => {
+    const candidate = createServer((_request, response) => {
+      response.writeHead(200, { "content-type": "application/json" });
+      response.end(body);
+    });
+    candidate.listen(0, "0.0.0.0", () => resolve(candidate));
+  });
+  const address = server.address();
+  if (!address || typeof address === "string") {
+    server.close();
+    throw new Error("Failed to start mock API server");
+  }
+
+  try {
+    await TestContainers.exposeHostPorts(address.port);
+    const client = await getContainerRuntimeClient();
+    const forwarder = (await client.container.list()).find(
+      (container) => container.State === "running" && container.Labels[TESTCONTAINERS_SSHD_LABEL] === "true",
+    );
+    const forwarderAddress = forwarder
+      ? Object.values(forwarder.NetworkSettings.Networks).find((network) => network.IPAddress)?.IPAddress
+      : undefined;
+    if (!forwarderAddress) throw new Error("Failed to locate the Testcontainers host-port forwarder");
+
+    return {
+      url: `http://${forwarderAddress}:${address.port}`,
+      close: () =>
+        new Promise((resolve, reject) => {
+          server.close((error) => (error ? reject(error) : resolve()));
+        }),
+    };
+  } catch (error) {
+    server.close();
+    throw error;
+  }
+}