add example for batch processing

Author: noxify

examples/batch-processing/.env.example

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+DATABASE_URL=postgresql://postgres:password@localhost:5432/queue_db

examples/batch-processing/drizzle.config.ts

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+import { defineConfig } from "drizzle-kit"
+
+export default defineConfig({
+  schema: "./src/schema.ts",
+  out: "./drizzle",
+  dialect: "postgresql",
+  dbCredentials: {
+    url: process.env.DATABASE_URL || "postgresql://postgres:postgres@localhost:5432/queue_tracking",
+  },
+})

examples/batch-processing/package.json

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+{
+  "name": "batch-processing-example",
+  "version": "1.0.0",
+  "description": "batch processing example using Drizzle ORM with postgres.js",
+  "type": "module",
+  "private": true,
+  "scripts": {
+    "dev": "tsx src/index.ts",
+    "db:push": "drizzle-kit push"
+  },
+  "dependencies": {
+    "@vorsteh-queue/adapter-drizzle": "workspace:*",
+    "@vorsteh-queue/core": "workspace:*",
+    "drizzle-orm": "^0.44.5",
+    "postgres": "^3.4.7"
+  },
+  "devDependencies": {
+    "drizzle-kit": "^0.31.4",
+    "tsx": "4.20.5",
+    "typescript": "^5.9.2"
+  }
+}

examples/batch-processing/readme.mdx

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+---
+title: Batch Processing Example
+navTitle: Batch Processing
+description: Demonstrates batch job processing. Shows how to register batch handlers, dispatch jobs in batches, and monitor batch events for robust, event-driven workflows.
+---
+
+## Setup
+
+Use the CLI to create this example:
+
+```bash
+npx create-vorsteh-queue@latest my-project --template batch-processing
+cd my-project
+cp .env.example .env
+# Edit .env with your PostgreSQL database URL
+pnpm db:push
+pnpm dev
+```

examples/batch-processing/src/database.ts

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+import { drizzle } from "drizzle-orm/postgres-js"
+import postgres from "postgres"
+
+import * as schema from "./schema"
+
+// Shared database connection
+const client = postgres(
+  process.env.DATABASE_URL || "postgresql://postgres:password@localhost:5432/queue_tracking",
+  { max: 10 } // Connection pool
+)
+
+export const db = drizzle(client, { schema })
+export { client }

examples/batch-processing/src/index.ts

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+import { PostgresQueueAdapter } from "@vorsteh-queue/adapter-drizzle"
+import { Queue } from "@vorsteh-queue/core"
+
+import { client, db } from "./database"
+
+// Queue setup with batch config
+const queue = new Queue(new PostgresQueueAdapter(db), {
+  name: "batch-demo",
+  batch: { minSize: 3, maxSize: 10, waitFor: 2000 },
+  removeOnComplete: 5,
+  removeOnFail: 3,
+})
+
+interface FilePayload {
+  file: string
+}
+interface FileResult {
+  ok: boolean
+}
+
+// Register a batch handler for processing files
+queue.registerBatch<FilePayload, FileResult>("process-files", async (jobs) => {
+  console.log(`Processing batch of ${jobs.length} files...`)
+  // Simulate processing
+  await Promise.all(
+    jobs.map(async (job) => {
+      await new Promise((resolve) => setTimeout(resolve, 200))
+      console.log(`  ✔️ Processed: ${job.payload.file}`)
+    }),
+  )
+  return jobs.map(() => ({ ok: true }))
+})
+
+// Listen to batch events
+queue.on("batch:processing", (jobs) => {
+  console.log(`Batch processing started: ${jobs.length} jobs`)
+})
+queue.on("batch:completed", (jobs) => {
+  console.log(`Batch completed: ${jobs.length} jobs`)
+})
+queue.on("batch:failed", ({ jobs, error }) => {
+  console.error(`Batch failed: ${jobs.length} jobs`, error)
+})
+
+async function main() {
+  console.log("🚀 Starting Batch Processing Example\n")
+
+  // Add jobs in a batch
+  await queue.addJobs("process-files", [
+    { file: "a.csv" },
+    { file: "b.csv" },
+    { file: "c.csv" },
+    { file: "d.csv" },
+  ])
+
+  // Start processing
+  queue.start()
+  console.log("🔄 Queue processing started!")
+
+  // Wait for batches to complete
+  setTimeout(async () => {
+    await queue.stop()
+    await client.end()
+    console.log("✅ Batch processing complete. Shutdown.")
+    process.exit(0)
+  }, 5000)
+}
+
+main().catch((error) => {
+  console.error("❌ Batch processing error:", error)
+  process.exit(1)
+})

examples/batch-processing/src/schema.ts

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+import { postgresSchema } from "@vorsteh-queue/adapter-drizzle"
+
+export const { queueJobs } = postgresSchema

examples/batch-processing/tsconfig.json

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+{
+  "compilerOptions": {
+    "target": "ES2022",
+    "module": "ESNext",
+    "moduleResolution": "bundler",
+    "strict": true,
+    "esModuleInterop": true,
+    "skipLibCheck": true,
+    "forceConsistentCasingInFileNames": true
+  },
+  "include": ["src/**/*"],
+  "exclude": ["node_modules", "dist"]
+}