fix(node-host): guard Claude CLI pipe errors (#109794)

* fix(node-host): guard Claude CLI stdout/stderr pipe errors

Co-authored-by: Cursor <cursoragent@cursor.com>

* fix(node-host): make request mock generic to fix test-types CI failure

* test(node-host): harden child pipe regression

---------

Co-authored-by: Cursor <cursoragent@cursor.com>
Co-authored-by: Peter Steinberger <steipete@gmail.com>

src/node-host/invoke-agent-cli-claude-pipe-error.test.ts

@@ -0,0 +1,69 @@
+import { afterEach, describe, expect, it, vi } from "vitest";
+
+const spawnMock = vi.hoisted(() => vi.fn());
+
+vi.mock("node:child_process", () => ({
+  spawn: spawnMock,
+}));
+
+import type { NodeHostClient } from "./client.js";
+import type { NodeInvokeRequestPayload } from "./invoke.js";
+
+function frame(params: unknown): NodeInvokeRequestPayload {
+  return {
+    id: "invoke-pipe-error",
+    nodeId: "node-pipe-error",
+    command: "agent.cli.claude.run.v1",
+    paramsJSON: JSON.stringify(params),
+  };
+}
+
+function client(): NodeHostClient {
+  return {
+    async request<T = Record<string, unknown>>() {
+      return {} as T;
+    },
+  };
+}
+
+describe("Claude CLI node command pipe errors", () => {
+  let realChild: import("node:child_process").ChildProcessWithoutNullStreams | undefined;
+
+  afterEach(() => {
+    if (realChild && !realChild.killed) {
+      realChild.kill("SIGKILL");
+    }
+    realChild = undefined;
+    spawnMock.mockReset();
+    vi.resetModules();
+  });
+
+  it("guards real child stdout/stderr pipe error events", async () => {
+    const childProcess =
+      await vi.importActual<typeof import("node:child_process")>("node:child_process");
+    realChild = childProcess.spawn(process.execPath, ["-e", "setInterval(() => {}, 1000)"], {
+      stdio: ["pipe", "pipe", "pipe"],
+    });
+    spawnMock.mockReturnValueOnce(realChild as never);
+    const { runClaudeCliNodeCommand } = await import("./invoke-agent-cli-claude.js");
+
+    const request = { argv: ["-p"], idleTimeoutMs: 100, timeoutMs: 5_000 };
+
+    const run = runClaudeCliNodeCommand({
+      client: client(),
+      frame: frame(request),
+      request,
+      argv: [process.execPath, ...request.argv],
+      cwd: undefined,
+      env: process.env as Record<string, string>,
+      timeoutMs: request.timeoutMs,
+    });
+
+    expect(() => realChild?.stdout.emit("error", new Error("stdout pipe failure"))).not.toThrow();
+    expect(() => realChild?.stderr.emit("error", new Error("stderr pipe failure"))).not.toThrow();
+    realChild.kill("SIGKILL");
+
+    await expect(run).resolves.toMatchObject({ success: false });
+    expect(spawnMock).toHaveBeenCalledOnce();
+  });
+});

src/node-host/invoke-agent-cli-claude.ts

@@ -165,6 +165,10 @@ export async function runClaudeCliNodeCommand(params: {
           terminalLineTouchesTruncation = false;
         }
       };
+      // Output pipes can fail independently; child close/error remains authoritative.
+      const ignoreOutputStreamError = () => {};
+      child.stdout.on("error", ignoreOutputStreamError);
+      child.stderr.on("error", ignoreOutputStreamError);
       child.stdout.on("data", (raw: Buffer) => {
         const retained = retain(raw);
         if (retained.length > 0) {