feat: AI conversation persistence with DB-backed history

.gitignore

@@ -17,6 +17,9 @@ logs/security/
 data/*
 !data/.gitkeep
 
+# Test and coverage outputs
+coverage/
+
 # Verification scripts
 verify-*.js
 VERIFICATION_GUIDE.md

biome.json

@@ -0,0 +1,36 @@
+{
+  "$schema": "https://biomejs.dev/schemas/2.3.14/schema.json",
+  "files": {
+    "includes": [
+      "src/db.js",
+      "src/index.js",
+      "src/modules/ai.js",
+      "tests/**/*.js",
+      "!node_modules/**",
+      "!coverage/**",
+      "!logs/**",
+      "!data/**"
+    ]
+  },
+  "linter": {
+    "enabled": true,
+    "rules": {
+      "suspicious": {
+        "noConsole": "error"
+      }
+    }
+  },
+  "formatter": {
+    "enabled": true,
+    "indentStyle": "space",
+    "indentWidth": 2,
+    "lineWidth": 100
+  },
+  "javascript": {
+    "formatter": {
+      "quoteStyle": "single",
+      "trailingCommas": "all",
+      "semicolons": "always"
+    }
+  }
+}

config.json

@@ -4,7 +4,9 @@
     "model": "claude-sonnet-4-20250514",
     "maxTokens": 1024,
     "systemPrompt": "You are Volvox Bot, the friendly AI assistant for the Volvox developer community Discord server.\n\nYou're witty, snarky (but warm), and deeply knowledgeable about programming, software development, and tech.\n\nKey traits:\n- Helpful but not boring\n- Can roast people lightly when appropriate\n- Enthusiastic about cool tech and projects\n- Supportive of beginners learning to code\n- Concise - this is Discord, not an essay\n\n⚠️ CRITICAL RULES:\n- NEVER type @.everyone or @.here (remove the dots) - these ping hundreds of people\n- NEVER use mass mention pings under any circumstances\n- If you need to address the group, say \"everyone\" or \"folks\" without the @ symbol\n\nKeep responses under 2000 chars. Use Discord markdown when helpful.",
-    "channels": []
+    "channels": [],
+    "historyLength": 20,
+    "historyTTLDays": 30
   },
   "chimeIn": {
     "enabled": false,

package.json

@@ -8,11 +8,17 @@
   "scripts": {
     "start": "node src/index.js",
     "dev": "node --watch src/index.js",
-    "deploy": "node src/deploy-commands.js"
+    "deploy": "node src/deploy-commands.js",
+    "test": "vitest run",
+    "test:watch": "vitest",
+    "test:coverage": "vitest run --coverage",
+    "lint": "biome check src/ tests/",
+    "lint:fix": "biome check --write src/ tests/",
+    "format": "biome format --write src/ tests/"
   },
   "dependencies": {
     "discord.js": "^14.25.1",
-    "dotenv": "^17.2.3",
+    "dotenv": "^17.2.4",
     "pg": "^8.18.0",
     "winston": "^3.19.0",
     "winston-daily-rotate-file": "^5.0.0"
@@ -24,5 +30,10 @@
   },
   "engines": {
     "node": ">=18.0.0"
+  },
+  "devDependencies": {
+    "@biomejs/biome": "^2.3.14",
+    "@vitest/coverage-v8": "^4.0.18",
+    "vitest": "^4.0.18"
   }
 }

src/db.js

@@ -96,6 +96,22 @@ export async function initDb() {
         )
       `);
 
+      await pool.query(`
+        CREATE TABLE IF NOT EXISTS conversations (
+          id SERIAL PRIMARY KEY,
+          channel_id TEXT NOT NULL,
+          role TEXT NOT NULL,
+          content TEXT NOT NULL,
+          username TEXT,
+          created_at TIMESTAMPTZ DEFAULT NOW()
+        )
+      `);
+
+      await pool.query(`
+        CREATE INDEX IF NOT EXISTS idx_conversations_channel_created
+        ON conversations (channel_id, created_at)
+      `);
+
       info('Database schema initialized');
     } catch (err) {
       // Clean up the pool so getPool() doesn't return an unusable instance

src/index.js

@@ -11,19 +11,26 @@
  * - Structured logging
  */
 
-import { Client, GatewayIntentBits, Collection } from 'discord.js';
+import { existsSync, mkdirSync, readdirSync, readFileSync, writeFileSync } from 'node:fs';
+import { dirname, join } from 'node:path';
+import { fileURLToPath } from 'node:url';
+import { Client, Collection, GatewayIntentBits } from 'discord.js';
 import { config as dotenvConfig } from 'dotenv';
-import { readdirSync, writeFileSync, readFileSync, existsSync, mkdirSync } from 'fs';
-import { join, dirname } from 'path';
-import { fileURLToPath } from 'url';
-import { info, warn, error } from './logger.js';
-import { initDb, closeDb } from './db.js';
-import { loadConfig, getConfig } from './modules/config.js';
+import { closeDb, initDb } from './db.js';
+import { error, info, warn } from './logger.js';
+import {
+  getConversationHistory,
+  initConversationHistory,
+  setConversationHistory,
+  setPool,
+  startConversationCleanup,
+  stopConversationCleanup,
+} from './modules/ai.js';
+import { loadConfig } from './modules/config.js';
 import { registerEventHandlers } from './modules/events.js';
 import { HealthMonitor } from './utils/health.js';
+import { getPermissionError, hasPermission } from './utils/permissions.js';
 import { registerCommands } from './utils/registerCommands.js';
-import { hasPermission, getPermissionError } from './utils/permissions.js';
-import { getConversationHistory, setConversationHistory } from './modules/ai.js';
 
 // ES module dirname equivalent
 const __filename = fileURLToPath(import.meta.url);
@@ -125,7 +132,7 @@ function loadState() {
  */
 async function loadCommands() {
   const commandsPath = join(__dirname, 'commands');
-  const commandFiles = readdirSync(commandsPath).filter(file => file.endsWith('.js'));
+  const commandFiles = readdirSync(commandsPath).filter((file) => file.endsWith('.js'));
 
   for (const file of commandFiles) {
     const filePath = join(commandsPath, file);
@@ -152,12 +159,7 @@ client.once('clientReady', async () => {
     const commands = Array.from(client.commands.values());
     const guildId = process.env.GUILD_ID || null;
 
-    await registerCommands(
-      commands,
-      client.user.id,
-      process.env.DISCORD_TOKEN,
-      guildId
-    );
+    await registerCommands(commands, client.user.id, process.env.DISCORD_TOKEN, guildId);
   } catch (err) {
     error('Command registration failed', { error: err.message });
   }
@@ -189,7 +191,7 @@ client.on('interactionCreate', async (interaction) => {
     if (!hasPermission(member, commandName, config)) {
       await interaction.reply({
         content: getPermissionError(commandName),
-        ephemeral: true
+        ephemeral: true,
       });
       warn('Permission denied', { user: interaction.user.tag, command: commandName });
       return;
@@ -200,7 +202,7 @@ client.on('interactionCreate', async (interaction) => {
     if (!command) {
       await interaction.reply({
         content: '❌ Command not found.',
-        ephemeral: true
+        ephemeral: true,
       });
       return;
     }
@@ -212,7 +214,7 @@ client.on('interactionCreate', async (interaction) => {
 
     const errorMessage = {
       content: '❌ An error occurred while executing this command.',
-      ephemeral: true
+      ephemeral: true,
     };
 
     if (interaction.replied || interaction.deferred) {
@@ -236,8 +238,8 @@ async function gracefulShutdown(signal) {
     info('Waiting for pending requests', { count: pendingRequests.size });
     const startTime = Date.now();
 
-    while (pendingRequests.size > 0 && (Date.now() - startTime) < SHUTDOWN_TIMEOUT) {
-      await new Promise(resolve => setTimeout(resolve, 100));
+    while (pendingRequests.size > 0 && Date.now() - startTime < SHUTDOWN_TIMEOUT) {
+      await new Promise((resolve) => setTimeout(resolve, 100));
     }
 
     if (pendingRequests.size > 0) {
@@ -247,23 +249,26 @@ async function gracefulShutdown(signal) {
     }
   }
 
-  // 2. Save state after pending requests complete
+  // 2. Stop conversation cleanup timer
+  stopConversationCleanup();
+
+  // 3. Save state after pending requests complete
   info('Saving conversation state');
   saveState();
 
-  // 3. Close database pool
+  // 4. Close database pool
   info('Closing database connection');
   try {
     await closeDb();
   } catch (err) {
     error('Failed to close database pool', { error: err.message });
   }
 
-  // 4. Destroy Discord client
+  // 5. Destroy Discord client
   info('Disconnecting from Discord');
   client.destroy();
 
-  // 5. Log clean exit
+  // 6. Log clean exit
   info('Shutdown complete');
   process.exit(0);
 }
@@ -277,15 +282,15 @@ client.on('error', (err) => {
   error('Discord client error', {
     error: err.message,
     stack: err.stack,
-    code: err.code
+    code: err.code,
   });
 });
 
 process.on('unhandledRejection', (err) => {
   error('Unhandled promise rejection', {
     error: err?.message || String(err),
     stack: err?.stack,
-    type: typeof err
+    type: typeof err,
   });
 });
 
@@ -307,8 +312,9 @@ if (!token) {
  */
 async function startup() {
   // Initialize database
+  let dbPool = null;
   if (process.env.DATABASE_URL) {
-    await initDb();
+    dbPool = await initDb();
     info('Database initialized');
   } else {
     warn('DATABASE_URL not set — using config.json only (no persistence)');
@@ -318,9 +324,20 @@ async function startup() {
   config = await loadConfig();
   info('Configuration loaded', { sections: Object.keys(config) });
 
-  // Load previous conversation state
+  // Set up AI module's DB pool reference
+  if (dbPool) {
+    setPool(dbPool);
+  }
+
+  // Load previous conversation state from file (fallback)
   loadState();
 
+  // Hydrate conversation history from DB (overwrites file state if DB is available)
+  await initConversationHistory();
+
+  // Start periodic conversation cleanup
+  startConversationCleanup();
+
   // Register event handlers with live config reference
   registerEventHandlers(client, config, healthMonitor);