problem connecting web3 v 1.2.1 with metamask : 'currentProvider' of undefined

Question

I am using Web3 v1.2.1 with nodejs v10 and following this link. I am having issue connecting with metamask,below is my code snippet:

const Web3 =  require('web3')  
const window = require('window');
const web3 = new Web3(window.Web3.currentProvider);

The error says TypeError: Cannot read property 'currentProvider' of undefined

I want to access the address from metamask, can someone help me with it

Answer 1

Metamask is a browser extension, so you can only use it from the browser.

You can do this in the following way:

Create a file web3-require.js:

Web3=require('web3');

Install web3 and browserify

npm install web3
npm install browserify

Create a browserified version of web3:

browserify web3-require.js -o web3-browserify.js 

Create test.html:

Test metamask
<script src="./web3-browserify.js"></script>
<script type="text/javascript">
    web3 = new Web3(Web3.givenProvider);    
    ethereum.enable().then ( (x) => {
        alert(`Found address ${x[0]} with web3.js version ${web3.version}`); 
    } );
</script>   

Run this from a webserver (otherwise metamask won't insert "ethereum")