feat(#1): Set up monorepo scaffold with pnpm workspaces + TurboRepo

Implements the foundational project structure including:
- pnpm workspaces configuration
- TurboRepo for build orchestration
- NestJS 11.1.12 API (apps/api)
- Next.js 16.1.6 web app (apps/web)
- Shared packages (config, shared, ui)
- TypeScript strict mode configuration
- ESLint + Prettier setup
- Vitest for unit testing (19 passing tests)

Fixes #1

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

apps/api/.swcrc

@@ -0,0 +1,18 @@
+{
+  "sourceMaps": true,
+  "jsc": {
+    "target": "es2022",
+    "parser": {
+      "syntax": "typescript",
+      "decorators": true
+    },
+    "transform": {
+      "legacyDecorator": true,
+      "decoratorMetadata": true
+    },
+    "keepClassNames": true
+  },
+  "module": {
+    "type": "es6"
+  }
+}

apps/api/nest-cli.json

@@ -0,0 +1,8 @@
+{
+  "$schema": "https://json.schemastore.org/nest-cli",
+  "collection": "@nestjs/schematics",
+  "sourceRoot": "src",
+  "compilerOptions": {
+    "deleteOutDir": true
+  }
+}

apps/api/package.json

@@ -0,0 +1,40 @@
+{
+  "name": "@mosaic/api",
+  "version": "0.0.1",
+  "private": true,
+  "scripts": {
+    "build": "nest build",
+    "dev": "nest start --watch",
+    "start": "node dist/main",
+    "start:debug": "nest start --debug --watch",
+    "start:prod": "node dist/main",
+    "lint": "eslint \"src/**/*.ts\"",
+    "lint:fix": "eslint \"src/**/*.ts\" --fix",
+    "typecheck": "tsc --noEmit",
+    "clean": "rm -rf dist",
+    "test": "vitest run",
+    "test:watch": "vitest",
+    "test:coverage": "vitest run --coverage",
+    "test:e2e": "vitest run --config ./vitest.e2e.config.ts"
+  },
+  "dependencies": {
+    "@nestjs/common": "^11.1.12",
+    "@nestjs/core": "^11.1.12",
+    "@nestjs/platform-express": "^11.1.12",
+    "@mosaic/shared": "workspace:*",
+    "reflect-metadata": "^0.2.2",
+    "rxjs": "^7.8.1"
+  },
+  "devDependencies": {
+    "@mosaic/config": "workspace:*",
+    "@nestjs/cli": "^11.0.6",
+    "@nestjs/schematics": "^11.0.1",
+    "@nestjs/testing": "^11.1.12",
+    "@swc/core": "^1.10.18",
+    "@types/express": "^5.0.1",
+    "@types/node": "^22.13.4",
+    "typescript": "^5.8.2",
+    "unplugin-swc": "^1.5.2",
+    "vitest": "^3.0.8"
+  }
+}

apps/api/src/app.controller.d.ts

@@ -0,0 +1,14 @@
+import { AppService } from "./app.service";
+import type { ApiResponse } from "@mosaic/shared/types";
+interface HealthStatus {
+    status: string;
+    timestamp: string;
+}
+export declare class AppController {
+    private readonly appService;
+    constructor(appService: AppService);
+    getHello(): string;
+    getHealth(): ApiResponse<HealthStatus>;
+}
+export {};
+//# sourceMappingURL=app.controller.d.ts.map

apps/api/src/app.controller.d.ts.map

@@ -0,0 +1 @@
+{"version":3,"file":"app.controller.d.ts","sourceRoot":"","sources":["app.controller.ts"],"names":[],"mappings":"AACA,OAAO,EAAE,UAAU,EAAE,MAAM,eAAe,CAAC;AAC3C,OAAO,KAAK,EAAE,WAAW,EAAE,MAAM,sBAAsB,CAAC;AAExD,UAAU,YAAY;IACpB,MAAM,EAAE,MAAM,CAAC;IACf,SAAS,EAAE,MAAM,CAAC;CACnB;AAED,qBACa,aAAa;IACZ,OAAO,CAAC,QAAQ,CAAC,UAAU;gBAAV,UAAU,EAAE,UAAU;IAGnD,QAAQ,IAAI,MAAM;IAKlB,SAAS,IAAI,WAAW,CAAC,YAAY,CAAC;CASvC"}

apps/api/src/app.controller.js

@@ -0,0 +1,50 @@
+"use strict";
+var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
+    var c = arguments.length, r = c < 3 ? target : desc === null ? desc = Object.getOwnPropertyDescriptor(target, key) : desc, d;
+    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") r = Reflect.decorate(decorators, target, key, desc);
+    else for (var i = decorators.length - 1; i >= 0; i--) if (d = decorators[i]) r = (c < 3 ? d(r) : c > 3 ? d(target, key, r) : d(target, key)) || r;
+    return c > 3 && r && Object.defineProperty(target, key, r), r;
+};
+var __metadata = (this && this.__metadata) || function (k, v) {
+    if (typeof Reflect === "object" && typeof Reflect.metadata === "function") return Reflect.metadata(k, v);
+};
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.AppController = void 0;
+const common_1 = require("@nestjs/common");
+const app_service_1 = require("./app.service");
+let AppController = class AppController {
+    appService;
+    constructor(appService) {
+        this.appService = appService;
+    }
+    getHello() {
+        return this.appService.getHello();
+    }
+    getHealth() {
+        return {
+            success: true,
+            data: {
+                status: "healthy",
+                timestamp: new Date().toISOString(),
+            },
+        };
+    }
+};
+exports.AppController = AppController;
+__decorate([
+    (0, common_1.Get)(),
+    __metadata("design:type", Function),
+    __metadata("design:paramtypes", []),
+    __metadata("design:returntype", String)
+], AppController.prototype, "getHello", null);
+__decorate([
+    (0, common_1.Get)("health"),
+    __metadata("design:type", Function),
+    __metadata("design:paramtypes", []),
+    __metadata("design:returntype", Object)
+], AppController.prototype, "getHealth", null);
+exports.AppController = AppController = __decorate([
+    (0, common_1.Controller)(),
+    __metadata("design:paramtypes", [app_service_1.AppService])
+], AppController);
+//# sourceMappingURL=app.controller.js.map

apps/api/src/app.controller.js.map

@@ -0,0 +1 @@
+{"version":3,"file":"app.controller.js","sourceRoot":"","sources":["app.controller.ts"],"names":[],"mappings":";;;;;;;;;;;;AAAA,2CAAiD;AACjD,+CAA2C;AASpC,IAAM,aAAa,GAAnB,MAAM,aAAa;IACK;IAA7B,YAA6B,UAAsB;QAAtB,eAAU,GAAV,UAAU,CAAY;IAAG,CAAC;IAGvD,QAAQ;QACN,OAAO,IAAI,CAAC,UAAU,CAAC,QAAQ,EAAE,CAAC;IACpC,CAAC;IAGD,SAAS;QACP,OAAO;YACL,OAAO,EAAE,IAAI;YACb,IAAI,EAAE;gBACJ,MAAM,EAAE,SAAS;gBACjB,SAAS,EAAE,IAAI,IAAI,EAAE,CAAC,WAAW,EAAE;aACpC;SACF,CAAC;IACJ,CAAC;CACF,CAAA;AAlBY,sCAAa;AAIxB;IADC,IAAA,YAAG,GAAE;;;;6CAGL;AAGD;IADC,IAAA,YAAG,EAAC,QAAQ,CAAC;;;;8CASb;wBAjBU,aAAa;IADzB,IAAA,mBAAU,GAAE;qCAE8B,wBAAU;GADxC,aAAa,CAkBzB"}

apps/api/src/app.controller.test.ts

@@ -0,0 +1,31 @@
+import { describe, expect, it } from "vitest";
+import { AppService } from "./app.service";
+import { AppController } from "./app.controller";
+
+describe("AppController", () => {
+  const appService = new AppService();
+  const controller = new AppController(appService);
+
+  describe("getHello", () => {
+    it('should return "Mosaic Stack API"', () => {
+      expect(controller.getHello()).toBe("Mosaic Stack API");
+    });
+  });
+
+  describe("getHealth", () => {
+    it("should return health status", () => {
+      const result = controller.getHealth();
+      expect(result.success).toBe(true);
+      expect(result.data.status).toBe("healthy");
+      expect(result.data.timestamp).toBeDefined();
+    });
+  });
+});
+
+describe("AppService", () => {
+  const service = new AppService();
+
+  it('should return "Mosaic Stack API"', () => {
+    expect(service.getHello()).toBe("Mosaic Stack API");
+  });
+});

apps/api/src/app.controller.ts

@@ -0,0 +1,29 @@
+import { Controller, Get } from "@nestjs/common";
+import { AppService } from "./app.service";
+import type { ApiResponse } from "@mosaic/shared";
+
+interface HealthStatus {
+  status: string;
+  timestamp: string;
+}
+
+@Controller()
+export class AppController {
+  constructor(private readonly appService: AppService) {}
+
+  @Get()
+  getHello(): string {
+    return this.appService.getHello();
+  }
+
+  @Get("health")
+  getHealth(): ApiResponse<HealthStatus> {
+    return {
+      success: true,
+      data: {
+        status: "healthy",
+        timestamp: new Date().toISOString(),
+      },
+    };
+  }
+}

apps/api/src/app.module.d.ts

@@ -0,0 +1,3 @@
+export declare class AppModule {
+}
+//# sourceMappingURL=app.module.d.ts.map

apps/api/src/app.module.d.ts.map

@@ -0,0 +1 @@
+{"version":3,"file":"app.module.d.ts","sourceRoot":"","sources":["app.module.ts"],"names":[],"mappings":"AAIA,qBAKa,SAAS;CAAG"}

apps/api/src/app.module.js

@@ -0,0 +1,23 @@
+"use strict";
+var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
+    var c = arguments.length, r = c < 3 ? target : desc === null ? desc = Object.getOwnPropertyDescriptor(target, key) : desc, d;
+    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") r = Reflect.decorate(decorators, target, key, desc);
+    else for (var i = decorators.length - 1; i >= 0; i--) if (d = decorators[i]) r = (c < 3 ? d(r) : c > 3 ? d(target, key, r) : d(target, key)) || r;
+    return c > 3 && r && Object.defineProperty(target, key, r), r;
+};
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.AppModule = void 0;
+const common_1 = require("@nestjs/common");
+const app_controller_1 = require("./app.controller");
+const app_service_1 = require("./app.service");
+let AppModule = class AppModule {
+};
+exports.AppModule = AppModule;
+exports.AppModule = AppModule = __decorate([
+    (0, common_1.Module)({
+        imports: [],
+        controllers: [app_controller_1.AppController],
+        providers: [app_service_1.AppService],
+    })
+], AppModule);
+//# sourceMappingURL=app.module.js.map

apps/api/src/app.module.js.map

@@ -0,0 +1 @@
+{"version":3,"file":"app.module.js","sourceRoot":"","sources":["app.module.ts"],"names":[],"mappings":";;;;;;;;;AAAA,2CAAwC;AACxC,qDAAiD;AACjD,+CAA2C;AAOpC,IAAM,SAAS,GAAf,MAAM,SAAS;CAAG,CAAA;AAAZ,8BAAS;oBAAT,SAAS;IALrB,IAAA,eAAM,EAAC;QACN,OAAO,EAAE,EAAE;QACX,WAAW,EAAE,CAAC,8BAAa,CAAC;QAC5B,SAAS,EAAE,CAAC,wBAAU,CAAC;KACxB,CAAC;GACW,SAAS,CAAG"}

apps/api/src/app.module.ts

@@ -0,0 +1,10 @@
+import { Module } from "@nestjs/common";
+import { AppController } from "./app.controller";
+import { AppService } from "./app.service";
+
+@Module({
+  imports: [],
+  controllers: [AppController],
+  providers: [AppService],
+})
+export class AppModule {}

apps/api/src/app.service.d.ts

@@ -0,0 +1,4 @@
+export declare class AppService {
+    getHello(): string;
+}
+//# sourceMappingURL=app.service.d.ts.map

apps/api/src/app.service.d.ts.map

@@ -0,0 +1 @@
+{"version":3,"file":"app.service.d.ts","sourceRoot":"","sources":["app.service.ts"],"names":[],"mappings":"AAEA,qBACa,UAAU;IACrB,QAAQ,IAAI,MAAM;CAGnB"}

apps/api/src/app.service.js

@@ -0,0 +1,20 @@
+"use strict";
+var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
+    var c = arguments.length, r = c < 3 ? target : desc === null ? desc = Object.getOwnPropertyDescriptor(target, key) : desc, d;
+    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") r = Reflect.decorate(decorators, target, key, desc);
+    else for (var i = decorators.length - 1; i >= 0; i--) if (d = decorators[i]) r = (c < 3 ? d(r) : c > 3 ? d(target, key, r) : d(target, key)) || r;
+    return c > 3 && r && Object.defineProperty(target, key, r), r;
+};
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.AppService = void 0;
+const common_1 = require("@nestjs/common");
+let AppService = class AppService {
+    getHello() {
+        return "Mosaic Stack API";
+    }
+};
+exports.AppService = AppService;
+exports.AppService = AppService = __decorate([
+    (0, common_1.Injectable)()
+], AppService);
+//# sourceMappingURL=app.service.js.map

apps/api/src/app.service.js.map

@@ -0,0 +1 @@
+{"version":3,"file":"app.service.js","sourceRoot":"","sources":["app.service.ts"],"names":[],"mappings":";;;;;;;;;AAAA,2CAA4C;AAGrC,IAAM,UAAU,GAAhB,MAAM,UAAU;IACrB,QAAQ;QACN,OAAO,kBAAkB,CAAC;IAC5B,CAAC;CACF,CAAA;AAJY,gCAAU;qBAAV,UAAU;IADtB,IAAA,mBAAU,GAAE;GACA,UAAU,CAItB"}

apps/api/src/app.service.ts

@@ -0,0 +1,8 @@
+import { Injectable } from "@nestjs/common";
+
+@Injectable()
+export class AppService {
+  getHello(): string {
+    return "Mosaic Stack API";
+  }
+}

apps/api/src/main.d.ts

@@ -0,0 +1,2 @@
+export {};
+//# sourceMappingURL=main.d.ts.map

apps/api/src/main.d.ts.map

@@ -0,0 +1 @@
+{"version":3,"file":"main.d.ts","sourceRoot":"","sources":["main.ts"],"names":[],"mappings":""}

apps/api/src/main.js

@@ -0,0 +1,16 @@
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+const core_1 = require("@nestjs/core");
+const app_module_1 = require("./app.module");
+async function bootstrap() {
+    const app = await core_1.NestFactory.create(app_module_1.AppModule);
+    app.enableCors();
+    const port = process.env["PORT"] ?? 3001;
+    await app.listen(port);
+    console.log(`API running on http://localhost:${port}`);
+}
+bootstrap().catch((err) => {
+    console.error("Failed to start application:", err);
+    process.exit(1);
+});
+//# sourceMappingURL=main.js.map

apps/api/src/main.js.map

@@ -0,0 +1 @@
+{"version":3,"file":"main.js","sourceRoot":"","sources":["main.ts"],"names":[],"mappings":";;AAAA,uCAA2C;AAC3C,6CAAyC;AAEzC,KAAK,UAAU,SAAS;IACtB,MAAM,GAAG,GAAG,MAAM,kBAAW,CAAC,MAAM,CAAC,sBAAS,CAAC,CAAC;IAChD,GAAG,CAAC,UAAU,EAAE,CAAC;IAEjB,MAAM,IAAI,GAAG,OAAO,CAAC,GAAG,CAAC,MAAM,CAAC,IAAI,IAAI,CAAC;IACzC,MAAM,GAAG,CAAC,MAAM,CAAC,IAAI,CAAC,CAAC;IAEvB,OAAO,CAAC,GAAG,CAAC,mCAAmC,IAAI,EAAE,CAAC,CAAC;AACzD,CAAC;AAED,SAAS,EAAE,CAAC,KAAK,CAAC,CAAC,GAAY,EAAE,EAAE;IACjC,OAAO,CAAC,KAAK,CAAC,8BAA8B,EAAE,GAAG,CAAC,CAAC;IACnD,OAAO,CAAC,IAAI,CAAC,CAAC,CAAC,CAAC;AAClB,CAAC,CAAC,CAAC"}

apps/api/src/main.ts

@@ -0,0 +1,17 @@
+import { NestFactory } from "@nestjs/core";
+import { AppModule } from "./app.module";
+
+async function bootstrap() {
+  const app = await NestFactory.create(AppModule);
+  app.enableCors();
+
+  const port = process.env["PORT"] ?? 3001;
+  await app.listen(port);
+
+  console.log(`API running on http://localhost:${port}`);
+}
+
+bootstrap().catch((err: unknown) => {
+  console.error("Failed to start application:", err);
+  process.exit(1);
+});

apps/api/tsconfig.json

@@ -0,0 +1,13 @@
+{
+  "extends": "@mosaic/config/typescript/nestjs",
+  "compilerOptions": {
+    "outDir": "./dist",
+    "rootDir": "./src",
+    "baseUrl": "./",
+    "paths": {
+      "@/*": ["src/*"]
+    }
+  },
+  "include": ["src/**/*"],
+  "exclude": ["node_modules", "dist", "**/*.spec.ts", "**/*.test.ts"]
+}

apps/api/vitest.config.ts

@@ -0,0 +1,27 @@
+import swc from "unplugin-swc";
+import { defineConfig } from "vitest/config";
+import path from "path";
+
+export default defineConfig({
+  test: {
+    globals: false,
+    environment: "node",
+    include: ["src/**/*.test.ts", "src/**/*.spec.ts"],
+    coverage: {
+      provider: "v8",
+      reporter: ["text", "json", "html"],
+      exclude: ["node_modules/", "dist/"],
+    },
+    setupFiles: ["./vitest.setup.ts"],
+  },
+  resolve: {
+    alias: {
+      "@": path.resolve(__dirname, "./src"),
+    },
+  },
+  plugins: [
+    swc.vite({
+      module: { type: "es6" },
+    }),
+  ],
+});

apps/api/vitest.setup.ts

@@ -0,0 +1 @@
+import "reflect-metadata";

apps/web/next-env.d.ts

@@ -0,0 +1,6 @@
+/// <reference types="next" />
+/// <reference types="next/image-types/global" />
+import "./.next/types/routes.d.ts";
+
+// NOTE: This file should not be edited
+// see https://nextjs.org/docs/app/api-reference/config/typescript for more information.

apps/web/next.config.ts

@@ -0,0 +1,7 @@
+import type { NextConfig } from "next";
+
+const nextConfig: NextConfig = {
+  transpilePackages: ["@mosaic/ui", "@mosaic/shared"],
+};
+
+export default nextConfig;

apps/web/package.json

@@ -0,0 +1,36 @@
+{
+  "name": "@mosaic/web",
+  "version": "0.0.1",
+  "private": true,
+  "scripts": {
+    "build": "next build",
+    "dev": "next dev --turbopack --port 3000",
+    "start": "next start",
+    "lint": "next lint",
+    "lint:fix": "next lint --fix",
+    "typecheck": "tsc --noEmit",
+    "clean": "rm -rf .next",
+    "test": "vitest run",
+    "test:watch": "vitest",
+    "test:coverage": "vitest run --coverage"
+  },
+  "dependencies": {
+    "@mosaic/shared": "workspace:*",
+    "@mosaic/ui": "workspace:*",
+    "next": "^16.1.6",
+    "react": "^19.0.0",
+    "react-dom": "^19.0.0"
+  },
+  "devDependencies": {
+    "@mosaic/config": "workspace:*",
+    "@testing-library/jest-dom": "^6.6.3",
+    "@testing-library/react": "^16.2.0",
+    "@types/node": "^22.13.4",
+    "@types/react": "^19.0.8",
+    "@types/react-dom": "^19.0.3",
+    "@vitejs/plugin-react": "^4.3.4",
+    "jsdom": "^26.0.0",
+    "typescript": "^5.8.2",
+    "vitest": "^3.0.8"
+  }
+}

apps/web/src/app/globals.css

@@ -0,0 +1,20 @@
+@tailwind base;
+@tailwind components;
+@tailwind utilities;
+
+:root {
+  --foreground-rgb: 0, 0, 0;
+  --background-rgb: 255, 255, 255;
+}
+
+@media (prefers-color-scheme: dark) {
+  :root {
+    --foreground-rgb: 255, 255, 255;
+    --background-rgb: 0, 0, 0;
+  }
+}
+
+body {
+  color: rgb(var(--foreground-rgb));
+  background: rgb(var(--background-rgb));
+}

apps/web/src/app/layout.tsx

@@ -0,0 +1,16 @@
+import type { Metadata } from "next";
+import type { ReactNode } from "react";
+import "./globals.css";
+
+export const metadata: Metadata = {
+  title: "Mosaic Stack",
+  description: "Mosaic Stack Web Application",
+};
+
+export default function RootLayout({ children }: { children: ReactNode }) {
+  return (
+    <html lang="en">
+      <body>{children}</body>
+    </html>
+  );
+}

apps/web/src/app/page.test.tsx

@@ -0,0 +1,22 @@
+import { describe, expect, it, afterEach } from "vitest";
+import { render, screen, cleanup } from "@testing-library/react";
+import Home from "./page";
+
+afterEach(() => {
+  cleanup();
+});
+
+describe("Home", () => {
+  it("should render the title", () => {
+    render(<Home />);
+    expect(screen.getByRole("heading", { level: 1 })).toHaveTextContent("Mosaic Stack");
+  });
+
+  it("should render the buttons", () => {
+    render(<Home />);
+    const buttons = screen.getAllByRole("button");
+    expect(buttons.length).toBe(2);
+    expect(buttons[0]).toHaveTextContent("Get Started");
+    expect(buttons[1]).toHaveTextContent("Learn More");
+  });
+});

apps/web/src/app/page.tsx

@@ -0,0 +1,16 @@
+import { Button } from "@mosaic/ui";
+
+export default function Home() {
+  return (
+    <main className="flex min-h-screen flex-col items-center justify-center p-24">
+      <h1 className="text-4xl font-bold mb-8">Mosaic Stack</h1>
+      <p className="text-lg text-gray-600 mb-8">
+        Welcome to the Mosaic Stack monorepo
+      </p>
+      <div className="flex gap-4">
+        <Button variant="primary">Get Started</Button>
+        <Button variant="secondary">Learn More</Button>
+      </div>
+    </main>
+  );
+}

apps/web/tsconfig.json

@@ -0,0 +1,11 @@
+{
+  "extends": "@mosaic/config/typescript/nextjs",
+  "compilerOptions": {
+    "baseUrl": ".",
+    "paths": {
+      "@/*": ["./src/*"]
+    }
+  },
+  "include": ["next-env.d.ts", "**/*.ts", "**/*.tsx", ".next/types/**/*.ts"],
+  "exclude": ["node_modules"]
+}

apps/web/vitest.config.ts

@@ -0,0 +1,23 @@
+import { defineConfig } from "vitest/config";
+import path from "path";
+import react from "@vitejs/plugin-react";
+
+export default defineConfig({
+  plugins: [react()],
+  test: {
+    globals: false,
+    environment: "jsdom",
+    include: ["src/**/*.test.tsx", "src/**/*.test.ts"],
+    coverage: {
+      provider: "v8",
+      reporter: ["text", "json", "html"],
+      exclude: ["node_modules/", ".next/"],
+    },
+    setupFiles: ["./vitest.setup.ts"],
+  },
+  resolve: {
+    alias: {
+      "@": path.resolve(__dirname, "./src"),
+    },
+  },
+});

apps/web/vitest.setup.ts

@@ -0,0 +1 @@
+import "@testing-library/jest-dom/vitest";