Method start

src/tools/launch-tool/utils/dev-server-manager.ts:155–210

(options: { timeoutMs: number } = { timeoutMs: 60_000 })

    }

    async start(options: { timeoutMs: number } = { timeoutMs: 60_000 }): Promise<DevServerHandle> {
        if (this.handle) {
            return this.handle;
        }

        const port = await getFreeHashPort(this.params.appPath);
        const url = buildDevServerUrl(port);
        const { executable, args, needsDoubleDash } = parseCommandWithPortSupport(this.params.runCommand);
        const normalizedExecutable = normalizeExecutable(executable);
        const commandArgs = needsDoubleDash ? [...args, '--', '--port', String(port)] : [...args, '--port', String(port)];

        logger.printInfoLog(`Starting dev server: ${normalizedExecutable} ${commandArgs.join(' ')}`);

        const child = spawn(normalizedExecutable, commandArgs, {
            cwd: this.params.appPath,
            stdio: ['ignore', 'pipe', 'pipe'],
            env: {
                ...process.env,
                PORT: String(port),
                FORCE_COLOR: '1',
            },
        });

        const maxBytes = 1_000_000;
        let out = '';
        const push = (chunk: Buffer) => {
            out += chunk.toString('utf-8');
            if (out.length > maxBytes) {
                out = out.slice(out.length - maxBytes);
            }
        };
        child.stdout?.on('data', push);
        child.stderr?.on('data', push);

        // If our process exits, try to stop the child to avoid orphans.
        process.once('exit', () => {
            terminateChildProcess(child);
        });

        const ready = await waitForServerReady(url, options.timeoutMs);
        if (!ready) {
            const tail = out.trim();
            terminateChildProcess(child);
            throw new Error(`Dev server did not become ready at ${url} within ${options.timeoutMs}ms.\n${tail}`);
        }

        this.handle = {
            child,
            port,
            url,
            outputTail: () => out.trim(),
        };

        logger.printSuccessLog(`Dev server ready at ${url}`);
        return this.handle;
    }

    async stop(): Promise<void> {