Function runOneClient

e2e/local/cli-mcp-daemon-attach-stress.test.ts:142–187

(
  id: number,
  dataDir: string,
  callCount: number,
)

 * always close. Never throws — failures are captured in the report so the
 * scenario can assert across the whole fleet. */
const runOneClient = async (
  id: number,
  dataDir: string,
  callCount: number,
): Promise<ClientReport> => {
  const transport = new StdioClientTransport({
    command: "bun",
    args: ["run", "dev:cli", "mcp", "--scope", testScope],
    cwd: repoRoot,
    env: { ...process.env, EXECUTOR_DATA_DIR: dataDir },
    stderr: "pipe",
  });
  const client = new Client({ name: `stress-client-${id}`, version: "1.0.0" });
  const results: string[] = [];
  let errBuf = "";
  transport.stderr?.on("data", (d: Buffer) => {
    errBuf += d.toString();
  });
  // oxlint-disable-next-line executor/no-try-catch-or-throw -- boundary: capture per-client failure for fleet-wide assertions
  try {
    await client.connect(transport);
    const { tools } = await client.listTools();
    for (let i = 0; i < callCount; i++) {
      // A value unique to (client, call) so a misrouted reply is detectable.
      const expr = `return ${id} * 1000 + ${i}`;
      const r = await client.callTool({ name: "execute", arguments: { code: expr } });
      const text = (r.content as Array<{ type: string; text: string }>)[0]?.text ?? "";
      results.push(text);
    }
    return { id, ok: true, tools: tools.length, results };
  } catch (error) {
    return {
      id,
      ok: false,
      tools: 0,
      results,
      error:
        (error instanceof Error ? error.message : String(error)) +
        (errBuf
          ? `\n     stderr: ${errBuf.trim().split("\n").slice(-6).join("\n             ")}`
          : ""),
    };
  } finally {
    await transport.close().catch(() => undefined);
  }
};

const withTempData = Effect.acquireRelease(
  Effect.sync(() => {