module depends on deprecated "request" which has issues with certs

[Giszmo]

My BTCPayServer is using a letsencrypt cert which is affected by this issue. As explained in the link, the browser has no issue with expired certs but my api call fails.

$ node
> const key = "redacted"
> const btcpay = require('btcpay')
> const keypair = btcpay.crypto.load_keypair(new Buffer.from(key, 'hex'))
> const client = new btcpay.BTCPayClient("https://pos.btcpay.nz", keypair, {merchant: 'redacted'})
> client.get_invoices({status: "complete"}).then( invoices => {})
Promise { <pending> }
> (node:2032689) UnhandledPromiseRejectionWarning: RequestError: Error: certificate has expired
    at new RequestError (/path/to/project/node_modules/request-promise-core/lib/errors.js:14:15)
    at Request.plumbing.callback (/path/to/project/node_modules/request-promise-core/lib/plumbing.js:87:29)
    at Request.RP$callback [as _callback] (/path/to/project/node_modules/request-promise-core/lib/plumbing.js:46:31)
    at self.callback (/path/to/project/node_modules/request/request.js:185:22)
    at Request.emit (events.js:193:13)
    at Request.EventEmitter.emit (domain.js:481:20)
    at Request.onRequestError (/path/to/project/node_modules/request/request.js:877:8)
    at ClientRequest.emit (events.js:193:13)
    at ClientRequest.EventEmitter.emit (domain.js:481:20)
    at TLSSocket.socketErrorListener (_http_client.js:397:9)
    at TLSSocket.emit (events.js:193:13)
    at TLSSocket.EventEmitter.emit (domain.js:481:20)
    at emitErrorNT (internal/streams/destroy.js:91:8)
    at emitErrorAndCloseNT (internal/streams/destroy.js:59:3)
    at processTicksAndRejections (internal/process/task_queues.js:81:17)
(node:2032689) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). (rejection id: 1)
(node:2032689) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.

As the crash is caused in btcpay.BTCPayClient, I suspect this should be fixed in this project?

[Giszmo]

I needed to get this to work so I upgraded node to v16.11.0 and tried stuff found here. Your module might not be the culprit. For me, only the dangerous process.env.NODE_TLS_REJECT_UNAUTHORIZED = 0 worked.

[takinbo]

Thanks for reporting this and the follow up. As mentioned in the link you shared. This is an upstream issue but we should take a look and find a solution or at least warn the user so they know what's happening. If you come up with an elegant fix for the problem, do contribute.