How to create a local module in TypeScript

By the sounds of it, what you're wanting to do is package up your local my-module so that it can be used in the same way you'd install and use a package from the npm registry.

When you're doing local development, its easy to configure a dependency to reference to your module as a file path - though you need to have your typescript transpiled for it to work in your case.

Here's the method I'm using for local development, in an environment where we have many utility modules for a microservices architecture. I package the module into an archive and install it using npm install:

• Use npm pack to package the module into a .tgz. Our package.json defines the target directory to be packaged, and the build script performs the transpile into the target (obviously adjust for your needs):

  ...
  "main": "dist/index.js",
  "types": "dist/index.d.ts",
  "files": [
    "dist"
  ],
  "scripts": {
    "build": "npx babel src --out-dir dist --extensions .ts,.tsx,.js --ignore **/*.test.ts,**/*.test.tsx",
  ...

• Run npm pack and install the generated package in your application

/my-module/> npm pack
/my-module/> cd ../my-app
/my-app/> npm install --save ../my-module/my-module-0.0.1.tgz

Or as an all-in-one (builds tgz in my-app dir):

/my-app/> && npm pack ../my-module && npm i -s my-module-0.0.1.tgz

Once you're done with development, you'll probably want to publish your module in a way that its available to your project(s) on deployment.

Your options are along the lines of:

• Publish to your local system using npm link
• Publish to a private registry
• Publish to the npm registry (as either a public or private module)

Here's a good resource for these options: https://medium.com/@debshish.pal/publish-a-npm-package-locally-for-testing-9a00015eb9fd

Add local module as dependency to package.json (in the root of your project):

  "dependencies": {
    "my-module": "file:src/modules/my-module",
    ...
  }

Configure your typescript settings like here @tsconfig/recommended

Run npm install my-module in your root folder

Then you can do:

import {A} from 'my-module'

You can transpile your external local project (reference project) since Typescript 3 in July 2018.

See: How to share code between TypeScript projects?

Creating a package for local use seems to be straight forward

npm init -y
npm install typescript ts-node --save-dev
npx tsc --init

Compiler options:

{
  "compilerOptions": {
    ...
    "outDir": "./dist",
     // other configurations
    ...
  },
  ...
}

Also do remember to create an 'index.ts' file or similar that exports required files:

// index.ts

export * from './inner-folder1/my-file1.ts';
export * from './inner-folder2/my-file1.ts'
export * from './inner-folder2/my-file2.ts'

then from another package's root folder npm install ../mypackage

you'll be able to import from whatever available in the index file