expect(callToolMock).not.toHaveBeenCalled();

expect(closeMock).toHaveBeenCalled();

});

it("keeps only a byte-bounded plugin-tools MCP stderr tail on call failures", async () => {

listToolsMock.mockResolvedValueOnce({

tools: [{ name: "plugin.echo" }] as never[],

});

callToolMock.mockImplementationOnce(async () => {

const stderrListener = stderrOnMock.mock.calls[0]?.[1] as

| ((chunk: unknown) => void)

| undefined;

stderrListener?.(

Buffer.from(`old stderr${"x".repeat(12_000)}\nrecent MCP stderr tail`),

);

throw new Error("tool call failed");

});

const error = await callPluginToolsMcp({

env: {

gateway: {

tempRoot: gatewayTempRoot,

runtimeEnv: {

PATH: "/usr/bin",

},

},

repoRoot,

} as never,

toolName: "plugin.echo",

args: { text: "hello" },

}).catch((value: unknown) => value);

expect(error).toBeInstanceOf(Error);

const message = error instanceof Error ? error.message : String(error);

expect(message).toContain("tool call failed");

expect(message).toContain("MCP stderr tail:");

expect(message).toContain("MCP stderr truncated to last");

expect(message).toContain("recent MCP stderr tail");

expect(message).not.toContain("old stderr");

expect(closeMock).toHaveBeenCalled();

});

});

import path from "node:path";

import { Client } from "@modelcontextprotocol/sdk/client/index.js";

import { StdioClientTransport } from "@modelcontextprotocol/sdk/client/stdio.js";

import {

appendQaChildOutputTail,

createQaChildOutputTail,

formatQaChildOutputTail,

} from "./child-output.js";

import { extractQaToolPayload } from "./extract-tool-payload.js";

import { resolveQaNodeExecPath } from "./node-exec.js";

import type {

cwd: params.env.gateway.tempRoot,

env: transportEnv,

});

let stderrTail = "";

const stderrTail = createQaChildOutputTail(MCP_STDERR_TAIL_LIMIT);

const stderr = transport.stderr;

if (stderr && typeof stderr.on === "function") {

stderr.on("data", (chunk: unknown) => {

stderrTail = `${stderrTail}${String(chunk)}`.slice(-MCP_STDERR_TAIL_LIMIT);

appendQaChildOutputTail(stderrTail, chunk);

});

}

const client = new Client({ name: "openclaw-qa-suite", version: "0.0.0" }, {});

{ timeout: MCP_REQUEST_TIMEOUT_MS },

);

} catch (error) {

const tail = stderrTail.trim();

const tail = formatQaChildOutputTail(stderrTail, "MCP stderr").trim();

if (!tail || !(error instanceof Error)) {

throw error;

}