Hi, everyone 👋 I'm Fatih. I'm a front end developer from Turkey and this is my first post about my first react native library that I published to npm 2 days ago.

First of all, if you wanna take a look at it:
NPM
GitHub Repo

It's a dropdown component that let's you pick a country dial-in code for your phone number input.

So, it's been 5 months since I started to work as a professional front end developer. I mainly work with React but I am relatively new in React Native development. I was working on OTP login with firebase and I built a phone number input. Everything was okay but something was missing, a country code picker. So I checked the dropdown/picker packages but since they were not customizable and and I had my own design on my mind, I decided to build my own. At the end, I built a nice, searchable country code picker with flags and everything and my boss liked it a lot and suggested that I should publish it to NPM.

It was a process that I've made some research to get it done and learned many things about creating a package and publishing it. So, I decided to share this steps with the community.

Initializing the project

Initialize a React Native bare workflow project with TypeScript:

npx react-native init AwesomeTSProject --template react-native-template-typescript

Dependencies and package.json configuration

The most important thing is to get the package.json right. It contains all the necessary information about your soon-to-be package. Now, don't copy paste the info below, take a look at your package.json and edit/add fields accordingly:

{
  "name": "@digieggs-rn-country-code-picker", // Your package's name
  "version": "1.0.0", // Keep it 1.0.0 for now. It will increase automatically when you patch the project
  "main": "lib/module/index.js", // Entry point of the package
  "module": "lib/module/index.js", // Entry point of the package
  "react-native": "src/index.ts", // Entry point of the project
  "types": "lib/typescript/index.d.ts", // Entry point of the type definitions
  "description": "A searchable dropdown component to select a country code for your phone number input.", // Description to show on npmjs.com
  "files": [
    "lib/",
    "src/"
  ], // Entry point of the necessary files
  "keywords": [
    "react-native",
    "country",
    "country-code",
    "dialing code",
    "picker",
    "mobile",
    "ios",
    "android"
  ], // Some keywords to make the package easier to be found
  "bugs": {
    "url": "https://github.com/DIGIEGGS/rn-country-code-picker/issues"
  },
  "scripts": {
    "android": "react-native run-android",
    "ios": "react-native run-ios",
    "start": "react-native start",
    "test": "jest",
    "lint": "eslint . --ext .js,.jsx,.ts,.tsx",
    "prepare": "bob build" // The command to build our package's core
  },
  "dependencies": {
    "react": "16.13.1",
    "react-native": "0.63.3",
    "react-native-svg": "^12.1.0"
  },
  "devDependencies": {
    ...
    "@react-native-community/bob": "^0.16.2", // The builder. I'll talk about it
  },
  "peerDependencies": { // Add the dependencies that you want the user to install manually here. In my case it react-native-svg for the icons in the component
    "react-native-svg": "^12.1.0"
  },
  "repository": {
    "type": "git",
    "url": "git+https://github.com/DIGIEGGS/rn-country-code-picker"
  }, // repository info to show on npmjs.com
  "author": "Fatih Can <contact@fatihcan.dev>", // author info to show on npmjs.com
  "license": "MIT", // license info,
  "@react-native-community/bob": {
    "source": "src",
    "output": "lib",
    "targets": [
      "module",
      "typescript"
    ]
  } // Config for the builder bob
}

After you are done with the package.json, let's install our dependencies with yarn or npm:

yarn or npm install

The most important dependency here is:

This library will compile the ts files to js files and build type definitions of our components into a lib folder.

TypeScript configuration

After that, let's get to the tsconfig.json. You can copy/paste it if you like:

{
  "compilerOptions": {
    "allowSyntheticDefaultImports": true,
    "jsx": "react-native",
    "lib": ["dom", "esnext"],
    "moduleResolution": "node",
    "skipLibCheck": true,
    "resolveJsonModule": true,
    "strict": true
  },
  "include": ["src/index.ts"],
  "exclude": ["node_modules", "babel.config.js", "metro.config.js", "jest.config.js"]
}

Source folder and necessary files

After that, let's create a src folder. This folder will contain the source of our package:

After that, create an index.ts file and export the main component like this:

export { default as CallingCodePicker } from './CallingCodePicker';

It's almost done. Let's create the necessary ignore files and we will build our package.

.gitignore

...

# generated files by bob
lib/

.eslintignore

node_modules/

# generated files by bob
lib/

.npmignore

tsconfig.json
src

# Logs
*.log
npm-debug.log

# Dependency directory
node_modules

# Runtime data
tmp

Building the library

Now, let's run the following command to build our package with bob:

yarn run prepare

If you see the following logs, it means our package is ready to test:

Testing

Run the following command:

npm pack

builder-bob will compress our project into a .tgz file that allows us to install it with yarn/npm into another project to see if it being installed successfully.

Now, you should see a .tgz file in the structure. Move it to Desktop and initialize another React Native project. I know... 🥱 Bear with me 👊

After that project is initialized, change the following path with the path of your .tgz file and run:

npm install C:\Users\digieggs\Desktop\digieggs-rn-country-code-picker-1.0.4.tgz
or
yarn add C:\Users\digieggs\Desktop\digieggs-rn-country-code-picker-1.0.4.tgz

After a successfull installation, you can import the component like this:

import { CallingCodePicker } from '@digieggs/rn-country-code-picker'

GitHub configuration

We need a GitHub repo if you wish to share the code with everyone and maintain the project. Run the following commands with appropriate names:

git init
git add .
git commit -m “Initial commit”
git remote add origin https://github.com/<username>/<package_name>.git
git push -u origin master

Don't forget to edit the repository and bugs section in package.json.

Publishing to NPM

After that, we are ready to publish our package. Run the following command to define a user. It will ask you your username, password and email.

npm adduser

Make sure to confirm you email address before running the publish command:

npm publish

And congrats! 🥳 The package is live and ready to be installed from anywhere with the following commands:

npm install <package_name>
or
yarn add <package_name>

Conclusion

You've just built your first npm package. Publishing a package may seem hard but it's not. I hope it was a clear guide, it's my first tutorial blog post. Please feel free to ask questions if you got stuck anywhere.