blockchain.js | simple blockchain in javascript | Blockchain library

You have to export the Block class:

You should instantiate the classes like

If you type value in console, you'll see that the value is too big that javascript transform the value.

It seems normal to me that your console.log(this.chain) shows a pending promise. It's the very nature of asynchronous code.

What does this.chain.then(result => console.log(result)) tell you? It should give you the results of the operation.

EDIT

Can you show the code where you instantiate Blockchain?. I'd try this:

load_blocks() is asynchronous. It does not return the finished string because the readline code inside that function is asynchronous and has not yet finished when load_blocks() returns so thus return_string does not yet have the value you want when you return.

This is a classic asynchronous programming problem in Javascript. Your load_blocks function needs to either return a promise or call a callback when it finishes its work and the caller has to use that returned promise or callback to obtain the final result.

For a lot more info on returning an asynchronous value, see the various options offered here: How do I return the response from an asynchronous call?

You could change the code to something like this: