npm Module to React Native - react-native

Question

I’m trying to install the npm module wallet-address-validator in a React Native application. I am using expo for my development environment.
First I install wallet-address-validator
npm install wallet-address-validator
Then I run
expo start
And I get these errors
Expo Developer Tools is disconnected from Expo CLI. Use the expo start command to start the CLI again.
[14:23:00] Opening DevTools in the browser... (press shift-d to disable)
[14:23:02] Error: React native is not installed. Please run npm install in your project directory.
[14:23:02] Couldn't start project. Please fix the errors and restart the project.
[14:23:02] Set EXPO_DEBUG=true in your env to view the stack trace.
So I ran
npm install
Then I ran
expo start again
and I get this error
14:26
Recrawled this watch 1 times, most recently because: /home/dale/Desktop/Rails/TestApps/testApp: dir missing from internal state To resolve, please review the information on https://facebook.github.io/watchman/docs/troubleshooting.html#recrawl To clear this warning, run: watchman watch-del /home/dale/Desktop/Rails/TestApps/testApp ; watchman watch-project /home/dale/Desktop/Rails/TestApps/testApp

Answer 1

1) yarn add wallet-address-validator
2) npm install -g browserify
3) Create a file wav-in.js that imports the wallet-address-validator module and simply exports it:
var WAValidator = require('wallet-address-validator');
module.exports = WAValidator;
4) Then in the terminal in the project
browserify cwav-in.js -o wav.js
5) This will result in an error if you put in the test code below from Wallet-Address-validator in App.js
var WAValidator = require('wallet-address-validator');
var valid = WAValidator.validate('1KFzzGtDdnq5hrwxXGjwVnKzRbvf8WVxck', 'BTC');
if(valid)
console.log('This is a valid address');
else
console.log('Address INVALID');
6) You will however, get an error along the lines “… is not a function”
7) On line 3837 of wav.js change “var WAValidator = require('wallet-address-validator');” to “WAValidator = require('wallet-address-validator');”
8) On the very last line in of wav.js add “module.exports = WAValidator;”
everything should be working now
This article is also on point https://hackernoon.com/using-core-node-js-modules-in-react-native-apps-64acd4d07140