add isAddressUsed to bitcore-explorers

[maraoz]

See: https://labs.bitpay.com/t/how-to-get-utxos-for-an-hd-wallet/369

isAddressUsed should receive an address and return true if the address ever received a transaction

[dskloet]

Thanks!

Something more advanced to support HD wallets would be great as well. For example giving a window size of addresses to generate from an extended public key and finding all the unspent outputs from that, increasing the window as long as used addresses continue to be found.

[dskloet]

I just noticed that 3 days earlier Insight.address() was added which can tell the total amount received on an address.

bitpay/bitcore-explorers@05dd58a

The function name isn't super clear but it should do the trick for checking if an address is used.

[dskloet]

Unfortunately that code is broken. Issue 1175.

[maraoz]

should be fixed with https://github.com/bitpay/bitcore-explorers, can you review it?

[dskloet]

I think I've reviewed it. Can you see the comments I left or do I need to send them out or something?

[braydonf]

Moved to: bitpay/bitcore-explorers#32