ltomaszewski · July 9, 2025 06:36 · Jul 9, 2025
diff --git a/init-monorepo.js b/init-monorepo.js
@@ -0,0 +1,338 @@
+// Filename: init-monorepo.js
+// Description: A project-agnostic script to bootstrap a complete Node.js/TypeScript monorepo.
+// Usage: node init-monorepo.js
+
+const fs = require('fs');
+const path =require('path');
+const { execSync } = require('child_process');
+const readline = require('readline');
+
+// --- Helper Functions ---
+
+function createFile(filePath, content) {
+  const dir = path.dirname(filePath);
+  if (!fs.existsSync(dir)) {
+    fs.mkdirSync(dir, { recursive: true });
+  }
+  fs.writeFileSync(filePath, content.trim());
+  console.log(`✅ Created ${filePath}`);
+}
+
+function toPascalCase(str) {
+  return str.split('-').map(word => word.charAt(0).toUpperCase() + word.slice(1)).join('');
+}
+
+// --- File Content Templates ---
+
+const fileTemplates = {
+  gitignore: `
+# ## General Node.js ##
+# Logs
+logs
+*.log
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+lerna-debug.log*
+pnpm-debug.log*
+
+# Runtime data
+pids
+*.pid
+*.seed
+*.pid.lock
+
+# Dependency directories
+node_modules/
+
+# Optional npm cache directory
+.npm
+
+# Optional eslint cache
+.eslintcache
+
+# Output of 'npm pack'
+*.tgz
+
+# dotenv environment variables file
+.env
+.env.test
+.env.production
+.env.local
+.env.*.local
+
+# Mac files
+.DS_Store
+
+# ## TypeScript & Build Output ##
+/packages/*/dist
+/apps/*/dist
+*.tsbuildinfo
+
+# ## Project Specific ##
+.idea/
+.vscode/
+`,
+
+  rootPackageJson: (projectName) => JSON.stringify({
+    name: projectName,
+    private: true,
+    version: "1.0.0",
+    description: "A modular monorepo.",
+    main: "index.js",
+    scripts: {
+      "create:package": `node scripts/create-package.js`,
+      "create:app": `node scripts/create-package.js --app`,
+      "build": "npx tsc --build",
+      "test": "npm run test --workspaces",
+      "clean": "npm run clean --workspaces"
+    },
+    keywords: [],
+    author: "",
+    license: "ISC",
+    workspaces: [
+      "packages/*",
+      "apps/*"
+    ]
+  }, null, 2),
+
+  jestConfig: `
+/** @type {import('ts-jest').JestConfigWithTsJest} */
+module.exports = {
+  // Use ts-jest as a preset
+  preset: 'ts-jest',
+
+  // Set the test environment to Node.js
+  testEnvironment: 'node',
+
+  // Ignore the compiled 'dist' folder when running tests
+  testPathIgnorePatterns: ['/node_modules/', '/dist/'],
+};
+`,
+
+  tsconfigBase: `
+{
+  "compilerOptions": {
+    "target": "es2020",
+    "module": "commonjs",
+    "sourceMap": true,
+    "strict": true,
+    "moduleResolution": "node",
+    "esModuleInterop": true,
+    "forceConsistentCasingInFileNames": true,
+    "skipLibCheck": true,
+    "noEmitOnError": true,
+    "composite": true,
+    "declaration": true,
+    "declarationMap": true,
+    "incremental": true
+  }
+}
+`,
+
+  rootTsconfig: `
+{
+  "files": [],
+  "references": []
+}
+`,
+
+  createPackageScript: (scopeName) => `
+const fs = require('fs');
+const path = require('path');
+
+const scope = '@${scopeName}';
+const args = process.argv.slice(2);
+const isApp = args.includes('--app');
+const packageName = args.find(arg => !arg.startsWith('--'));
+
+if (!packageName) {
+  console.error('Error: Please provide a package name.');
+  console.log('Usage: node scripts/create-package.js [--app] <package-name>');
+  process.exit(1);
+}
+
+const baseDir = isApp ? 'apps' : 'packages';
+const templatesDir = path.join(__dirname, 'templates');
+
+function toPascalCase(str) {
+  return str.split('-').map(word => word.charAt(0).toUpperCase() + word.slice(1)).join('');
+}
+
+const className = toPascalCase(packageName);
+const fullPackageName = \`\${scope}/\${packageName}\`;
+const packagePath = path.join(baseDir, packageName);
+const srcPath = path.join(packagePath, 'src');
+const testsPath = path.join(srcPath, '__tests__');
+
+console.log(\`Creating \${isApp ? 'app' : 'package'}: \${fullPackageName} at \${packagePath}\`);
+
+if (fs.existsSync(packagePath)) {
+  console.error(\`Error: Directory already exists at \${packagePath}\`);
+  process.exit(1);
+}
+
+fs.mkdirSync(testsPath, { recursive: true });
+
+function createFileFromTemplate(templateName, destinationPath, replacements = {}) {
+  const templatePath = path.join(templatesDir, templateName);
+  let content = fs.readFileSync(templatePath, 'utf8');
+  for (const key in replacements) {
+    // Using string concatenation to build the RegExp to avoid nested template literal issues.
+    content = content.replace(new RegExp('{{' + key + '}}', 'g'), replacements[key]);
+  }
+  fs.writeFileSync(destinationPath, content);
+}
+
+const packageJsonTemplate = JSON.parse(fs.readFileSync(path.join(templatesDir, 'package.json.template'), 'utf8'));
+const finalPackageJson = { name: fullPackageName, ...packageJsonTemplate };
+fs.writeFileSync(path.join(packagePath, 'package.json'), JSON.stringify(finalPackageJson, null, 2));
+
+createFileFromTemplate('tsconfig.json.template', path.join(packagePath, 'tsconfig.json'));
+createFileFromTemplate('jest.config.js.template', path.join(packagePath, 'jest.config.js'));
+createFileFromTemplate('index.ts.template', path.join(srcPath, 'index.ts'), { className });
+createFileFromTemplate('index.test.ts.template', path.join(testsPath, 'index.test.ts'), { className });
+
+const rootTsconfigPath = path.join(__dirname, '..', 'tsconfig.json');
+try {
+  const rootTsconfigContent = fs.readFileSync(rootTsconfigPath, 'utf8');
+  const rootTsconfigJson = JSON.parse(rootTsconfigContent);
+  const newReference = { path: \`\${baseDir}/\${packageName}\` };
+  if (!rootTsconfigJson.references.some(ref => ref.path === newReference.path)) {
+    rootTsconfigJson.references.push(newReference);
+    rootTsconfigJson.references.sort((a, b) => a.path.localeCompare(b.path));
+  }
+  fs.writeFileSync(rootTsconfigPath, JSON.stringify(rootTsconfigJson, null, 2) + '\\n');
+  console.log('✅ Automatically updated root tsconfig.json');
+} catch (error) {
+  console.error('⚠️  Could not update root tsconfig.json. Please add the reference manually.', error);
+}
+
+console.log(\`✅ Successfully created \${fullPackageName}.\`);
+console.log('Next steps:');
+console.log('Run \`npm install\` to link the new package.');
+`,
+
+  scaffold_packageJson: `
+{
+  "version": "1.0.0",
+  "main": "dist/index.js",
+  "types": "dist/index.d.ts",
+  "scripts": {
+    "build": "tsc --build",
+    "test": "tsc --build && jest",
+    "clean": "rm -rf dist tsconfig.tsbuildinfo"
+  },
+  "dependencies": {},
+  "description": "",
+  "keywords": [],
+  "author": "",
+  "license": "ISC",
+  "type": "commonjs"
+}
+`,
+
+  scaffold_tsconfig: `
+{
+  "extends": "../../tsconfig.base.json",
+  "compilerOptions": {
+    "outDir": "./dist",
+    "rootDir": "./src"
+  },
+  "include": ["src/**/*"],
+  "references": []
+}
+`,
+
+  scaffold_jestConfig: `
+// Import the root configuration
+const rootConfig = require("../../jest.config.js");
+
+module.exports = {
+  // Extend the root configuration
+  ...rootConfig,
+};
+`,
+
+  scaffold_indexTs: `
+/**
+ * A utility class for {{className}}.
+ */
+export class {{className}} {
+  /**
+   * Returns a greeting string.
+   * @returns A string that says "Hello from {{className}}!".
+   */
+  public static getGreeting(): string {
+    return "Hello from {{className}}!";
+  }
+}
+`,
+
+  scaffold_indexTestTs: `
+import { {{className}} } from "../index";
+
+describe("{{className}}", () => {
+  it("should return a greeting", () => {
+    expect({{className}}.getGreeting()).toBe("Hello from {{className}}!");
+  });
+});
+`
+};
+
+
+// --- Main Execution ---
+
+const rl = readline.createInterface({
+  input: process.stdin,
+  output: process.stdout
+});
+
+rl.question('Enter the project name (e.g., my-new-project): ', (projectName) => {
+  rl.question('Enter the NPM scope name (e.g., my-org): ', (scopeName) => {
+    console.log(`\n🚀 Initializing monorepo "${projectName}" with scope "@${scopeName}"...`);
+
+    // Create root project directory
+    if (fs.existsSync(projectName)) {
+      console.error(`Error: Directory "${projectName}" already exists.`);
+      rl.close();
+      return;
+    }
+    fs.mkdirSync(projectName);
+    process.chdir(projectName);
+
+    // Create core config files from templates
+    createFile('.gitignore', fileTemplates.gitignore);
+    createFile('package.json', fileTemplates.rootPackageJson(projectName));
+    createFile('jest.config.js', fileTemplates.jestConfig);
+    createFile('tsconfig.base.json', fileTemplates.tsconfigBase);
+    createFile('tsconfig.json', fileTemplates.rootTsconfig);
+
+    // Create scaffolding script and its templates
+    const scriptsDir = 'scripts';
+    const templatesDir = path.join(scriptsDir, 'templates');
+    fs.mkdirSync(templatesDir, { recursive: true });
+
+    createFile(path.join(scriptsDir, 'create-package.js'), fileTemplates.createPackageScript(scopeName));
+    createFile(path.join(templatesDir, 'package.json.template'), fileTemplates.scaffold_packageJson);
+    createFile(path.join(templatesDir, 'tsconfig.json.template'), fileTemplates.scaffold_tsconfig);
+    createFile(path.join(templatesDir, 'jest.config.js.template'), fileTemplates.scaffold_jestConfig);
+    createFile(path.join(templatesDir, 'index.ts.template'), fileTemplates.scaffold_indexTs);
+    createFile(path.join(templatesDir, 'index.test.ts.template'), fileTemplates.scaffold_indexTestTs);
+
+    // Install root dependencies
+    console.log('\n📦 Installing root dependencies...');
+    try {
+      execSync('npm install typescript ts-node jest ts-jest @types/node @types/jest --save-dev', { stdio: 'inherit' });
+    } catch (error) {
+      console.error('\n❌ Failed to install root dependencies.');
+      process.exit(1);
+    }
+
+    console.log('\n🎉 Monorepo setup complete!');
+    console.log(`\nNavigate to your new project: \`cd ${projectName}\``);
+    console.log('To create your first package, run: `npm run create:package -- my-first-package`');
+
+    rl.close();
+  });
+});