create-simple-monorepo

TypeScript Monorepo

This is a simple, yet powerful monorepo for TypeScript packages. It doesn't rely on any monorepo-specific libraries and uses TypeScript's project references feature to handle inter-package dependencies.

📦 Package Structure

Each package resides in its own directory under the packages/ directory. Each package has its own package.json and tsconfig.json files.

The package.json file includes the package's dependencies and scripts. The main field points to the CommonJS build, the types field points to the TypeScript declaration file of the CommonJS build, and the browser field points to the UMD build.

The tsconfig.json file extends the root tsconfig.json file and includes the compilerOptions.outDir option to specify the output directory for the TypeScript compiler.

🛠️ Scripts

Script	Description
yarn build	Compiles all TypeScript packages to CommonJS modules using the TypeScript compiler.
yarn build:cjs	Compiles TypeScript packages to CommonJS modules using the TypeScript compiler.
yarn build:umd	Builds UMD bundles for each package using esBuild.
yarn build:esm	Builds ESM modules for each package using esbuild.
yarn build:packageJson	Updates the package.json files in each package based on inter-package dependencies and paths to built files.
yarn publish:package	Publishes a package to the npm registry.
yarn publish:test	Publishes a package using Yalc for local testing.
yarn create:package	Creates a new package. It prompts for the package name, then creates the package directory and files.
yarn delete:package	Deletes a package. It prompts for the package name, then deletes the package directory and removes the package from the root tsconfig.json file.
yarn check:packages	Checks if each package is correctly configured in the root tsconfig.json and logs any errors.
yarn bump	Bumps the version of a package. It prompts for the package name and version type (major, minor, or patch), then updates the package's version.
yarn clean	Deletes the dist directory in each package. Useful for cleaning up build outputs before building again.

🚀 Getting Started

• Clone the repository: git clone <repository-url>.
• Install dependencies: yarn install.

🧱 Using one package inside another

In a monorepo setup, it's common to have one package depend on another. The order in which you perform the setup steps is very important. Here's the correct sequence:

• Declare the dependency: In the package.json file of the dependent package (e.g., bar), add a dependency to the package it depends on (e.g., foo):

"dependencies": {
  "foo": "*"
}

• add a reference to the dependency in tsconfig.json: In the tsconfig.json file of the dependent package (e.g., bar), add a reference to the package it depends on (e.g., foo):

"references": [
  { "path": "../foo" }
]

This tells TypeScript that bar depends on foo, so TypeScript will build foo first when you build bar.

• Import the dependency: In the TypeScript code of the dependent package, import the module it depends on using its package name:

import { foo } from 'foo';

• Build the packages: When building your packages, ensure that you build the dependencies before the dependent packages. You can use the provided scripts to build all packages:

yarn build

This will ensure that the compiled files of the dependencies are available for the dependent packages.

• Checking the configuration: To check if each package is correctly configured in the root tsconfig.json, you can use the provided script:

node scripts/check-packages.js

This script checks if each package in the packages directory is declared in both compilerOptions.paths and references in the root tsconfig.json. If a package is not declared in either of these, it logs an error message.