MCP Vision Relay

import { spawn } from "node:child_process"; export interface RunCommandOptions { cwd?: string; env?: NodeJS.ProcessEnv; timeoutMs?: number; onStdoutChunk?: (chunk: string) => void; onStderrChunk?: (chunk: string) => void; } export interface CommandResult { stdout: string; stderr: string; exitCode: number | null; signal: NodeJS.Signals | null; durationMs: number; } export class CommandError extends Error { constructor( message: string, public readonly result: CommandResult ) { super(message); this.name = "CommandError"; } } export async function runCommand( command: string, args: string[], options: RunCommandOptions = {} ): Promise<CommandResult> { const { cwd, env, timeoutMs, onStdoutChunk, onStderrChunk, } = options; return new Promise<CommandResult>((resolve, reject) => { const start = Date.now(); const child = spawn(command, args, { cwd, env: env ? { ...process.env, ...env } : process.env, stdio: ["ignore", "pipe", "pipe"], }); let stdout = ""; let stderr = ""; let settled = false; const timer = typeof timeoutMs === "number" ? setTimeout(() => { if (!settled) { child.kill("SIGTERM"); settled = true; reject( new CommandError("Command timed out", { stdout, stderr, exitCode: null, signal: "SIGTERM", durationMs: Date.now() - start, }) ); } }, timeoutMs) : undefined; child.stdout?.on("data", (chunk: Buffer) => { const text = chunk.toString("utf8"); stdout += text; onStdoutChunk?.(text); }); child.stderr?.on("data", (chunk: Buffer) => { const text = chunk.toString("utf8"); stderr += text; onStderrChunk?.(text); }); child.on("error", (error) => { if (settled) { return; } settled = true; if (timer) { clearTimeout(timer); } reject( new CommandError(error.message, { stdout, stderr, exitCode: null, signal: null, durationMs: Date.now() - start, }) ); }); child.on("close", (code, signal) => { if (settled) { return; } settled = true; if (timer) { clearTimeout(timer); } const result: CommandResult = { stdout, stderr, exitCode: code, signal, durationMs: Date.now() - start, }; if (code === 0) { resolve(result); } else { reject( new CommandError( `Command "${command}" exited with code ${code}`, result ) ); } }); }); }