How do you implement a plugin architecture in Node.js?

Question

Accepted Answer

**Plugin architecture** — extend functionality without modifying core code.

```javascript
// Plugin system
class PluginManager {
    constructor() {
        this.plugins = [];
        this.hooks = new Map();
    }

register(plugin) {
        this.plugins.push(plugin);
        if (plugin.hooks) {
            for (const [name, fn] of Object.entries(plugin.hooks)) {
                if (!this.hooks.has(name)) this.hooks.set(name, []);
                this.hooks.get(name).push(fn);
            }
        }
    }

async execute(hookName, context) {
        const hooks = this.hooks.get(hookName) || [];
        for (const hook of hooks) {
            await hook(context);
        }
        return context;
    }
}

// Plugin
const loggerPlugin = {
    name: "logger",
    hooks: {
        "request:start": async (ctx) => {
            console.log(`${ctx.method} ${ctx.url}`);
        },
        "request:end": async (ctx) => {
            console.log(`Finished in ${ctx.duration}ms`);
        },
    },
};

const manager = new PluginManager();
manager.register(loggerPlugin);
await manager.execute("request:start", { method: "GET", url: "/" });
```

**Key concepts:**
- Hooks for lifecycle events.
- Plugins register/unregister dynamically.
- Core remains unchanged.

Node.js: How do you implement a plugin architecture in Node.js?