@weaverslab/feature-flags/dist/index.js

Feature flags for CodeWeavers

import dotenv from 'dotenv';
import { sql } from 'drizzle-orm';
import { drizzle } from 'drizzle-orm/postgres-js';
import EventEmitter from 'events';
import { LRUCache } from 'lru-cache';
import { Pool } from 'pg';
dotenv.config();
class FeatureFlagService {
    constructor() {
        this.db = drizzle(new Pool({ connectionString: process.env.DATABASE_URL }));
        this.cache = new LRUCache({ max: 100, ttl: 60000 });
        this.events = new EventEmitter();
        this.initialize();
    }
    async initialize() {
        await this.loadFeatureFlags();
        this.listenForChanges();
    }
    async loadFeatureFlags() {
        const flags = await this.db.execute(sql `SELECT name, enabled FROM hub_feature_flag`);
        flags.forEach((flag) => this.cache.set(flag.name, flag.enabled));
    }
    async listenForChanges() {
        const client = new Pool({ connectionString: process.env.DATABASE_URL });
        const pgClient = await client.connect();
        pgClient.query('LISTEN feature_flag_changes');
        pgClient.on('notification', async () => {
            await this.loadFeatureFlags();
            this.events.emit('update');
        });
    }
    isEnabled(flagName) {
        return this.cache.get(flagName) ?? false;
    }
    onUpdate(callback) {
        this.events.on('update', callback);
    }
    static setDatabaseUrl(url) {
        process.env.DATABASE_URL = url;
    }
}
export { FeatureFlagService };