test: extraction middleware, module registry, and event flow test suites

Dockerfile

@@ -0,0 +1,14 @@
+FROM node:20-alpine AS builder
+WORKDIR /app
+COPY package*.json ./
+RUN npm ci
+COPY . .
+RUN npx nx build api --skip-nx-cache
+
+FROM node:20-alpine AS runner
+WORKDIR /app
+COPY --from=builder /app/dist/apps/api ./dist
+COPY --from=builder /app/node_modules ./node_modules
+COPY --from=builder /app/package.json ./
+EXPOSE 3000
+CMD ["node", "dist/main.js"]

apps/api/next.config.js

@@ -1,5 +1,24 @@
 /** @type {import('next').NextConfig} */
 const path = require('path');
+const webpack = require('webpack');
+
+const LIBS = path.resolve(__dirname, '../../libs');
+
+// Mirror tsconfig.base.json paths for webpack
+const pathMappings = [
+  // /internal subpaths first (more specific)
+  ['@tiny-store/modules-inventory/internal', 'modules/inventory/src/internal.ts'],
+  ['@tiny-store/modules-orders/internal', 'modules/orders/src/internal.ts'],
+  ['@tiny-store/modules-payments/internal', 'modules/payments/src/internal.ts'],
+  ['@tiny-store/modules-shipments/internal', 'modules/shipments/src/internal.ts'],
+  // Public APIs
+  ['@tiny-store/modules-inventory', 'modules/inventory/src/index.ts'],
+  ['@tiny-store/modules-orders', 'modules/orders/src/index.ts'],
+  ['@tiny-store/modules-payments', 'modules/payments/src/index.ts'],
+  ['@tiny-store/modules-shipments', 'modules/shipments/src/index.ts'],
+  ['@tiny-store/shared-infrastructure', 'shared/infrastructure/src/index.ts'],
+  ['@tiny-store/shared-domain', 'shared/domain/src/index.ts'],
+];
 
 const nextConfig = {
   serverExternalPackages: ['typeorm', 'sqlite3', 'reflect-metadata'],
@@ -9,10 +28,24 @@ const nextConfig = {
         ...config.resolve.alias,
         '@/lib': path.resolve(__dirname, 'src/app/lib'),
       };
+
+      // Use NormalModuleReplacementPlugin for @tiny-store/* paths
+      for (const [from, to] of pathMappings) {
+        const escaped = from.replace(/[.*+?^${}()|[\]\\\/]/g, '\\$&');
+        config.plugins.push(
+          new webpack.NormalModuleReplacementPlugin(
+            new RegExp(`^${escaped}$`),
+            path.join(LIBS, to)
+          )
+        );
+      }
+
+      if (!config.resolve.extensions.includes('.ts')) {
+        config.resolve.extensions.push('.ts');
+      }
     }
     return config;
   },
 };
 
 module.exports = nextConfig;
-

apps/api/src/app/lib/register-listeners.ts

@@ -7,6 +7,7 @@ import { EventStoreRepository } from '@tiny-store/shared-infrastructure';
 import { OrderPlacedListener } from '@tiny-store/modules-inventory';
 import { OrderCancelledListener } from '@tiny-store/modules-inventory';
 import { OrderPaymentFailedListener } from '@tiny-store/modules-inventory';
+import { registerStockSyncWorker } from '@tiny-store/modules-inventory';
 
 // Orders
 import { InventoryReservedListener } from '@tiny-store/modules-orders';
@@ -16,69 +17,31 @@ import { PaymentFailedListener } from '@tiny-store/modules-orders';
 import { ShipmentCreatedListener } from '@tiny-store/modules-orders';
 
 // Payments
-import { OrderConfirmedListener } from '@tiny-store/modules-payments';
 import { ProcessPaymentHandler } from '@tiny-store/modules-payments';
-
-// Payments - Jobs
 import { registerPaymentProcessingWorker } from '@tiny-store/modules-payments';
 
-// Inventory - Jobs
-import { registerStockSyncWorker } from '@tiny-store/modules-inventory';
-
 // Shipments
-import { OrderPaidListener } from '@tiny-store/modules-shipments';
 import { CreateShipmentHandler } from '@tiny-store/modules-shipments';
 import { registerLabelGenerationWorker } from '@tiny-store/modules-shipments';
 
-// Orders - for accessing order details
+// Orders - for accessing order details (used by payments + shipments)
 import { GetOrderHandler } from '@tiny-store/modules-orders';
 
-export function registerListeners(dataSource: DataSource): void {
-  const eventBus = EventBus.getInstance();
-  const eventStoreRepository = new EventStoreRepository(dataSource);
-
-  // Store all events
-  eventBus.subscribe('OrderPlaced', async (event) => {
-    await eventStoreRepository.save(event);
-  });
-  eventBus.subscribe('OrderConfirmed', async (event) => {
-    await eventStoreRepository.save(event);
-  });
-  eventBus.subscribe('OrderRejected', async (event) => {
-    await eventStoreRepository.save(event);
-  });
-  eventBus.subscribe('OrderPaid', async (event) => {
-    await eventStoreRepository.save(event);
-  });
-  eventBus.subscribe('OrderPaymentFailed', async (event) => {
-    await eventStoreRepository.save(event);
-  });
-  eventBus.subscribe('OrderShipped', async (event) => {
-    await eventStoreRepository.save(event);
-  });
-  eventBus.subscribe('OrderCancelled', async (event) => {
-    await eventStoreRepository.save(event);
-  });
-  eventBus.subscribe('InventoryReserved', async (event) => {
-    await eventStoreRepository.save(event);
-  });
-  eventBus.subscribe('InventoryReservationFailed', async (event) => {
-    await eventStoreRepository.save(event);
-  });
-  eventBus.subscribe('InventoryReleased', async (event) => {
-    await eventStoreRepository.save(event);
-  });
-  eventBus.subscribe('PaymentProcessed', async (event) => {
-    await eventStoreRepository.save(event);
-  });
-  eventBus.subscribe('PaymentFailed', async (event) => {
-    await eventStoreRepository.save(event);
-  });
-  eventBus.subscribe('ShipmentCreated', async (event) => {
-    await eventStoreRepository.save(event);
-  });
-
-  // Inventory listeners
+// ── Extraction Configuration ────────────────────────────────
+// Modules listed in EXTRACTED_MODULES run as independent services
+// and are skipped during monolith listener registration.
+const EXTRACTED_MODULES = new Set(
+  (process.env['EXTRACTED_MODULES'] || '')
+    .split(',')
+    .map((m) => m.trim().toLowerCase())
+    .filter(Boolean)
+);
+
+// ── Per-Module Registration Functions ───────────────────────
+// Each module defines its own listener wiring. Adding a new module
+// means adding one function and one entry to MODULE_REGISTRY.
+
+function registerInventoryListeners(dataSource: DataSource, eventBus: EventBus): void {
   const orderPlacedListener = new OrderPlacedListener(dataSource);
   eventBus.subscribe('OrderPlaced', (event) => orderPlacedListener.handle(event));
 
@@ -90,7 +53,12 @@ export function registerListeners(dataSource: DataSource): void {
     orderPaymentFailedListener.handle(event)
   );
 
-  // Orders listeners
+  registerStockSyncWorker(async (data: any) => {
+    console.log(`[StockSync] Processing ${data.items.length} items from ${data.source}`);
+  });
+}
+
+function registerOrdersListeners(dataSource: DataSource, eventBus: EventBus): void {
   const inventoryReservedListener = new InventoryReservedListener(dataSource);
   eventBus.subscribe('InventoryReserved', (event) =>
     inventoryReservedListener.handle(event)
@@ -109,11 +77,12 @@ export function registerListeners(dataSource: DataSource): void {
 
   const shipmentCreatedListener = new ShipmentCreatedListener(dataSource);
   eventBus.subscribe('ShipmentCreated', (event) => shipmentCreatedListener.handle(event));
+}
 
-  // Payments listener (custom implementation to get order amount)
+function registerPaymentsListeners(dataSource: DataSource, eventBus: EventBus): void {
   const processPaymentHandler = new ProcessPaymentHandler(dataSource);
   const getOrderHandler = new GetOrderHandler(dataSource);
-  
+
   eventBus.subscribe('OrderConfirmed', async (event) => {
     const { orderId } = event.payload;
     try {
@@ -127,9 +96,20 @@ export function registerListeners(dataSource: DataSource): void {
     }
   });
 
-  // Shipments listener (custom implementation to get shipping address)
+  registerPaymentProcessingWorker(async (data: any) => {
+    try {
+      await processPaymentHandler.handle(data);
+    } catch (error) {
+      console.error('Error processing payment via queue:', error);
+      throw error;
+    }
+  });
+}
+
+function registerShipmentsListeners(dataSource: DataSource, eventBus: EventBus): void {
   const createShipmentHandler = new CreateShipmentHandler(dataSource);
-
+  const getOrderHandler = new GetOrderHandler(dataSource);
+
   eventBus.subscribe('OrderPaid', async (event) => {
     const { orderId } = event.payload;
     try {
@@ -143,21 +123,49 @@ export function registerListeners(dataSource: DataSource): void {
     }
   });
 
-  // Register queue workers
   registerLabelGenerationWorker();
-  registerPaymentProcessingWorker(async (data) => {
-    try {
-      await processPaymentHandler.handle(data);
-    } catch (error) {
-      console.error('Error processing payment via queue:', error);
-      throw error; // Re-throw to trigger retry
-    }
-  });
-  registerStockSyncWorker(async (data) => {
-    console.log(`[StockSync] Processing ${data.items.length} items from ${data.source}`);
-    // In production: iterate items and call UpdateProductStockHandler per SKU
-  });
-
-  console.log('✅ Event listeners registered');
 }
 
+// ── Module Registry ─────────────────────────────────────────
+// Single place to add or remove modules. Extraction is controlled
+// entirely by the EXTRACTED_MODULES environment variable.
+const MODULE_REGISTRY: Record<string, (ds: DataSource, eb: EventBus) => void> = {
+  inventory: registerInventoryListeners,
+  orders: registerOrdersListeners,
+  payments: registerPaymentsListeners,
+  shipments: registerShipmentsListeners,
+};
+
+// ── Event Store (always active) ─────────────────────────────
+const ALL_EVENTS = [
+  'OrderPlaced', 'OrderConfirmed', 'OrderRejected',
+  'OrderPaid', 'OrderPaymentFailed', 'OrderShipped', 'OrderCancelled',
+  'InventoryReserved', 'InventoryReservationFailed', 'InventoryReleased',
+  'PaymentProcessed', 'PaymentFailed', 'ShipmentCreated',
+];
+
+// ── Orchestrator ────────────────────────────────────────────
+export function registerListeners(dataSource: DataSource): void {
+  const eventBus = EventBus.getInstance();
+  const eventStoreRepository = new EventStoreRepository(dataSource);
+
+  // Event store captures all events regardless of extraction
+  for (const eventName of ALL_EVENTS) {
+    eventBus.subscribe(eventName, (event) => eventStoreRepository.save(event));
+  }
+
+  // Register each non-extracted module
+  for (const [moduleName, register] of Object.entries(MODULE_REGISTRY)) {
+    if (EXTRACTED_MODULES.has(moduleName)) {
+      console.log(`⏭️  ${moduleName} listeners skipped (module extracted)`);
+      continue;
+    }
+    register(dataSource, eventBus);
+  }
+
+  if (EXTRACTED_MODULES.size > 0) {
+    console.log(`✅ Event listeners registered (extracted: ${[...EXTRACTED_MODULES].join(', ')})`);
+  } else {
+    console.log('✅ Event listeners registered');
+  }
+}

apps/api/src/middleware.ts

@@ -0,0 +1,44 @@
+/**
+ * L3 Extraction Middleware
+ *
+ * When EXTRACTED_MODULES is set (e.g., "orders"), the monolith
+ * rejects requests to extracted module routes with 410 Gone.
+ * A reverse proxy (nginx, API gateway) forwards these to the
+ * extracted service; this middleware is the safety net.
+ *
+ * This demonstrates that extraction is a configuration change,
+ * not a code change.
+ */
+import { NextRequest, NextResponse } from 'next/server';
+
+const EXTRACTED_MODULES = (process.env['EXTRACTED_MODULES'] || '')
+  .split(',')
+  .map((m) => m.trim().toLowerCase())
+  .filter(Boolean);
+
+const MODULE_ROUTE_PREFIXES: Record<string, string> = {
+  orders: '/api/orders',
+  inventory: '/api/inventory',
+  // Future: payments, shipments, etc.
+};
+
+export function middleware(request: NextRequest) {
+  for (const mod of EXTRACTED_MODULES) {
+    const prefix = MODULE_ROUTE_PREFIXES[mod];
+    if (prefix && request.nextUrl.pathname.startsWith(prefix)) {
+      return NextResponse.json(
+        {
+          error: 'Gone',
+          message: `The ${mod} module has been extracted to a dedicated service.`,
+          service: `${mod}-service`,
+        },
+        { status: 410 }
+      );
+    }
+  }
+  return NextResponse.next();
+}
+
+export const config = {
+  matcher: '/api/:path*',
+};

apps/orders-service/Dockerfile

@@ -0,0 +1,18 @@
+# Orders Service — L3 Extraction
+# Uses the same libs/modules/orders code as the monolith.
+# Only the entry point and database connection differ.
+
+FROM node:20-alpine AS builder
+WORKDIR /app
+COPY package*.json ./
+RUN npm ci
+COPY . .
+RUN npx tsc -p apps/orders-service/tsconfig.json
+
+FROM node:20-alpine AS runner
+WORKDIR /app
+COPY --from=builder /app/dist/apps/orders-service ./dist
+COPY --from=builder /app/node_modules ./node_modules
+COPY --from=builder /app/package.json ./
+EXPOSE 3001
+CMD ["node", "dist/apps/orders-service/src/main.js"]

apps/orders-service/project.json

@@ -0,0 +1,20 @@
+{
+  "name": "orders-service",
+  "root": "apps/orders-service",
+  "sourceRoot": "apps/orders-service/src",
+  "projectType": "application",
+  "targets": {
+    "build": {
+      "executor": "nx:run-commands",
+      "options": {
+        "command": "npx tsc -p apps/orders-service/tsconfig.json"
+      }
+    },
+    "serve": {
+      "executor": "nx:run-commands",
+      "options": {
+        "command": "npx ts-node -r tsconfig-paths/register apps/orders-service/src/main.ts"
+      }
+    }
+  }
+}