added two other varieties of module registration

packages/server/package.json

@@ -28,7 +28,7 @@
     "fastify": "^4.23.2",
     "fastify-type-provider-zod": "^1.1.9",
     "mongodb": "^6.1.0",
-    "nanoid": "^4.0.2",
+    "nanoid": "^3.3.7",
     "reflect-metadata": "^0.2.2",
     "rxjs": "^7.8.1",
     "ts-byob": "^1.0.3",

packages/server/src/adapters/memory.module.ts

@@ -0,0 +1,30 @@
+import {DynamicModule} from "@nestjs/common";
+import {CART_REPO, ORDER_REPO, PRODUCT_REPO} from "./index";
+import {MemoryCartRepository} from "./cart.repo";
+import {InMemoryOrderRepository, InMemoryProductRepository} from "./fake";
+import {ProductTemplate} from "../types";
+
+
+export class MemoryModule {
+    static forTests(products: ProductTemplate[]): DynamicModule {
+        return {
+            module: MemoryModule,
+            providers: [
+
+                {
+                    provide: PRODUCT_REPO,
+                    useValue: new InMemoryProductRepository(products)
+                },
+                {
+                    provide: ORDER_REPO,
+                    useClass: InMemoryOrderRepository,
+                },
+                {
+                    provide: CART_REPO,
+                    useClass: MemoryCartRepository,
+                }
+            ],
+            exports: [PRODUCT_REPO, ORDER_REPO, CART_REPO]
+        }
+    }
+}

packages/server/src/adapters/mongodb.module.ts

@@ -0,0 +1,42 @@
+import {MongoClient} from "mongodb";
+import {DynamicModule} from "@nestjs/common";
+import {CART_REPO, ORDER_REPO, PRODUCT_REPO} from "./index";
+import {MongoDBProductRepository} from "./product.repo";
+import {MongoDBOrderRepository} from "./order.repo";
+import {MemoryCartRepository} from "./cart.repo";
+
+export class MongoDBModule {
+    static forRoot(uri: string): DynamicModule {
+
+        return {
+            module: MongoDBModule,
+            providers: [
+                {
+                    provide: "storeDB",
+                    useFactory: async () => {
+                        const mongo = await new MongoClient(uri, {
+                            connectTimeoutMS: 100,
+                            serverSelectionTimeoutMS: 100,
+                            socketTimeoutMS: 100
+                        }).connect();
+
+                        return mongo.db("store");
+                    },
+                },
+                {
+                    provide: PRODUCT_REPO,
+                    useClass: MongoDBProductRepository
+                },
+                {
+                    provide: ORDER_REPO,
+                    useClass: MongoDBOrderRepository,
+                },
+                {
+                    provide: CART_REPO,
+                    useClass: MemoryCartRepository,
+                }
+            ],
+            exports: [PRODUCT_REPO, ORDER_REPO, CART_REPO]
+        }
+    }
+}

packages/server/src/adapters/order.repo.ts

@@ -1,6 +1,6 @@
 import { Collection, Db, ObjectId, WithId } from "mongodb";
 import { Order } from "../types";
-import {Injectable} from "@nestjs/common";
+import {Inject, Injectable} from "@nestjs/common";
 
 type MongoOrder = Omit<Order, "id">;
 const docToOrder = ({_id, ...rest}: WithId<MongoOrder>) => Order.parse({id: _id.toString(), ...rest});
@@ -9,7 +9,7 @@ const docToOrder = ({_id, ...rest}: WithId<MongoOrder>) => Order.parse({id: _id.
 export class MongoDBOrderRepository {
     private orders: Collection<MongoOrder>;
 
-    constructor(db: Db) {
+    constructor(@Inject("storeDB") db: Db) {
         this.orders = db.collection("orders");
     }
 

packages/server/src/adapters/product.repo.ts

@@ -1,14 +1,14 @@
 import { Collection, Db, ObjectId, WithId } from "mongodb";
 import { Product, ProductTemplate } from "../types";
-import {Injectable} from "@nestjs/common";
+import {Inject, Injectable} from "@nestjs/common";
 
 const docToProduct = ({_id, ...rest}: WithId<ProductTemplate>) => Product.parse({id: _id.toString(), ...rest});
 
 @Injectable()
 export class MongoDBProductRepository {
     private products: Collection<ProductTemplate>;
 
-    constructor(db: Db) {
+    constructor(@Inject("storeDB") db: Db) {
         this.products = db.collection("products");
     }
 

packages/server/src/app.module.ts → packages/server/src/app.module.ioc.ts

@@ -6,10 +6,10 @@ import {CART_REPO, ORDER_REPO, PRODUCT_REPO} from "./adapters";
 import {MemoryCartRepository} from "./adapters/cart.repo";
 
 @Module({})
-export class AppModule {
+export class AppModuleInversionOfControl {
     static register(productRepo: ProductRepository, orderRepo: OrderRepository): DynamicModule {
         return {
-            module: AppModule,
+            module: AppModuleInversionOfControl,
             providers: [
                 {
                     provide: PRODUCT_REPO,

packages/server/src/app.module.overrides.ts

@@ -0,0 +1,11 @@
+import { Module} from "@nestjs/common";
+import {CartController, CheckoutController, OrderController, ProductController} from "./controllers";
+import {MongoDBModule} from "./adapters/mongodb.module";
+
+@Module({
+    imports: [MongoDBModule.forRoot(`mongodb://root:[email protected]`)],
+    controllers: [CartController, ProductController, OrderController, CheckoutController]
+})
+export class AppModuleOverrides {
+
+}

packages/server/src/app.module.register.ts

@@ -0,0 +1,14 @@
+import {DynamicModule, Module} from "@nestjs/common";
+import {CartController, CheckoutController, OrderController, ProductController} from "./controllers";
+
+
+@Module({})
+export class AppModuleWithRegister {
+    static register(adapters: DynamicModule) {
+        return {
+            imports: [adapters],
+            controllers: [CartController, ProductController, OrderController, CheckoutController],
+            module: AppModuleWithRegister
+        }
+    }
+}

packages/server/src/index.ts

@@ -2,9 +2,13 @@ import { MongoClient } from "mongodb";
 import { MongoDBOrderRepository } from "./adapters/order.repo";
 import { MongoDBProductRepository } from "./adapters/product.repo";
 import {NestFactory} from "@nestjs/core";
-import {AppModule} from "./app.module";
+import {AppModuleInversionOfControl} from "./app.module.ioc";
+import {AppModuleOverrides} from "./app.module.overrides";
+import {AppModuleWithRegister} from "./app.module.register";
+import {MongoDBModule} from "./adapters/mongodb.module";
 
-async function startServer() {
+// @ts-ignore
+async function startServerIoC() {
   const mongo = await new MongoClient(
     `mongodb://root:[email protected]?retryWrites=true&writeConcern=majority`
   ).connect();
@@ -13,11 +17,26 @@ async function startServer() {
   const productRepo = new MongoDBProductRepository(db);
   const orderRepo = new MongoDBOrderRepository(db);
 
-  const app = await NestFactory.create(AppModule.register(productRepo, orderRepo))
+  const app = await NestFactory.create(AppModuleInversionOfControl.register(productRepo, orderRepo))
   app.enableCors({origin: "*"});
   await app.listen(8080);
 }
 
-void startServer();
+// @ts-ignore
+async function startServerOverrides() {
+  const app = await NestFactory.create(AppModuleOverrides)
+  app.enableCors({origin: "*"});
+  await app.listen(8080);
+}
+
+async function startServerRegister() {
+  const app = await NestFactory.create(AppModuleWithRegister.register(
+      MongoDBModule.forRoot(`mongodb://root:[email protected]`)
+  ));
+  app.enableCors({origin: "*"});
+  await app.listen(8080);
+}
+
+void startServerRegister();
 
 

packages/server/src/server.testkit.ts

@@ -1,17 +1,68 @@
 import {ProductTemplate} from "./types";
 import {Test} from "@nestjs/testing";
 import {InMemoryOrderRepository, InMemoryProductRepository} from "./adapters/fake";
-import {AppModule} from "./app.module";
-export async function createTestingModule(products: ProductTemplate[] = []) {
+import {AppModuleInversionOfControl} from "./app.module.ioc";
+import {AppModuleOverrides} from "./app.module.overrides";
+import {ORDER_REPO, PRODUCT_REPO} from "./adapters";
+import {MongoDBModule} from "./adapters/mongodb.module";
+import {Module} from "@nestjs/common";
+import {AppModuleWithRegister} from "./app.module.register";
+import {MemoryModule} from "./adapters/memory.module";
+export async function createTestingModuleWithIoC(products: ProductTemplate[] = []) {
     const productRepo = new InMemoryProductRepository(products);
     const orderRepo = new InMemoryOrderRepository();
     const testingModule = await Test.createTestingModule({
-        imports: [AppModule.register(productRepo, orderRepo)],
+        imports: [AppModuleInversionOfControl.register(productRepo, orderRepo)],
     })
         .compile();
 
     const nest = testingModule.createNestApplication();
     nest.enableCors({origin: "*"});
     await nest.init();
     return {nest, orderRepo, productRepo};
-}
+}
+
+export async function createTestingModuleWithOverrides(products: ProductTemplate[] = []) {
+    const productRepo = new InMemoryProductRepository(products);
+    const orderRepo = new InMemoryOrderRepository();
+    const testingModule = await Test.createTestingModule({
+        imports: [AppModuleOverrides],
+    })
+        .overrideModule(MongoDBModule).useModule(NopModule) // this doesn't actually do anything, MongoDB needs to be available for connection even though we don't use it
+        .overrideProvider(PRODUCT_REPO).useValue(productRepo)
+        .overrideProvider(ORDER_REPO).useValue(orderRepo)
+        .compile();
+
+    const nest = testingModule.createNestApplication();
+    nest.enableCors({origin: "*"});
+    await nest.init();
+    return {nest, orderRepo, productRepo};
+}
+
+export async function createTestingModuleWithRegister(products: ProductTemplate[] = []) {
+
+    const testingModule = await Test.createTestingModule({
+        imports: [AppModuleWithRegister.register(MemoryModule.forTests(products))],
+    })
+        .compile();
+
+    const productRepo: InMemoryProductRepository = testingModule.get(PRODUCT_REPO);
+    const orderRepo: InMemoryOrderRepository = testingModule.get(ORDER_REPO);
+
+    const nest = testingModule.createNestApplication();
+    nest.enableCors({origin: "*"});
+    await nest.init();
+    return {nest, orderRepo, productRepo};
+}
+
+// export const createTestingModule = createTestingModuleWithOverrides;
+// export const createTestingModule = createTestingModuleWithIoC;
+export const createTestingModule = createTestingModuleWithRegister;
+
+@Module({
+    providers: [{
+        provide: "storeDB",
+        useValue: null
+    }],
+})
+class NopModule{}

yarn.lock

@@ -1964,7 +1964,7 @@ __metadata:
     fastify-type-provider-zod: ^1.1.9
     jest: ^28.1.3
     mongodb: ^6.1.0
-    nanoid: ^4.0.2
+    nanoid: ^3.3.7
     nodemon: ^3.0.1
     reflect-metadata: ^0.2.2
     rxjs: ^7.8.1
@@ -6611,6 +6611,15 @@ __metadata:
   languageName: node
   linkType: hard
 
+"nanoid@npm:^3.3.7":
+  version: 3.3.7
+  resolution: "nanoid@npm:3.3.7"
+  bin:
+    nanoid: bin/nanoid.cjs
+  checksum: d36c427e530713e4ac6567d488b489a36582ef89da1d6d4e3b87eded11eb10d7042a877958c6f104929809b2ab0bafa17652b076cdf84324aa75b30b722204f2
+  languageName: node
+  linkType: hard
+
 "nanoid@npm:^4.0.2":
   version: 4.0.2
   resolution: "nanoid@npm:4.0.2"