What does this?

[br14n-sol]

const { data } = await axios('https://blockchain.info/q/addressbalance/' + address + '?confirmations=3');
if (data.includes('error')) { // this
   return -1;
}

I understand that axios with the status 404 directly throws an error, so the check does not work, right?

[roberthgnz]

Works, because the data return this...

{
  "error": "not-found-or-invalid-arg",
  "message": "Item not found or argument invalid"
}

[br14n-sol]

Works, because the data return this...

{
  "error": "not-found-or-invalid-arg",
  "message": "Item not found or argument invalid"
}

I think you misunderstood what I meant 😅

In axios, when a call returns a 404 status code, it directly throws an error stopping the application completely, for example, the following code:

const not_exist = await walletfy.getBalance('btc', 'not_exist')
console.log(not_exist)

would throw the following in the console:

(node:10200) UnhandledPromiseRejectionWarning: Error: Request failed with status code 404
    at createError (~\Walletfy\node_modules\axios\lib\core\createError.js:16:15)
    at settle (~\Walletfy\node_modules\axios\lib\core\settle.js:17:12)
    at IncomingMessage.handleStreamEnd (~\Walletfy\node_modules\axios\lib\adapters\http.js:293:11)
    at IncomingMessage.emit (events.js:387:35)
    at endReadableNT (internal/streams/readable.js:1317:12)
    at processTicksAndRejections (internal/process/task_queues.js:82:21)
(Use `node --trace-warnings ...` to show where the warning was created)
(node:10200) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catchate the node process on unhandled promise rejection, use the CLI flag `--unhandled-rejections=strict` (see https://nodejs.org/api/cli.html#cli_unhandled_rejections_mode). (rejection id: 2)
(node:10200) [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.

This type of errors should be handled internally in the library and return something more descriptive to the user.

---

I did something for it in the sumcoin implementation, following what was mentioned in Pull request #4

const not_exist = await walletfy.getBalance('sum', 'not_exist')
console.log(not_exist)

returns the following in the console:

-1

[roberthgnz]

Works, because the data return this...

{
  "error": "not-found-or-invalid-arg",
  "message": "Item not found or argument invalid"
}

I think you misunderstood what I meant 😅

In axios, when a call returns a 404 status code, it directly throws an error stopping the application completely, for example, the following code:

const not_exist = await walletfy.getBalance('btc', 'not_exist')
console.log(not_exist)

would throw the following in the console:

(node:10200) UnhandledPromiseRejectionWarning: Error: Request failed with status code 404
    at createError (~\Walletfy\node_modules\axios\lib\core\createError.js:16:15)
    at settle (~\Walletfy\node_modules\axios\lib\core\settle.js:17:12)
    at IncomingMessage.handleStreamEnd (~\Walletfy\node_modules\axios\lib\adapters\http.js:293:11)
    at IncomingMessage.emit (events.js:387:35)
    at endReadableNT (internal/streams/readable.js:1317:12)
    at processTicksAndRejections (internal/process/task_queues.js:82:21)
(Use `node --trace-warnings ...` to show where the warning was created)
(node:10200) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catchate the node process on unhandled promise rejection, use the CLI flag `--unhandled-rejections=strict` (see https://nodejs.org/api/cli.html#cli_unhandled_rejections_mode). (rejection id: 2)
(node:10200) [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.

This type of errors should be handled internally in the library and return something more descriptive to the user.

I did something for it in the sumcoin implementation, following what was mentioned in Pull request #4

const not_exist = await walletfy.getBalance('sum', 'not_exist')
console.log(not_exist)

returns the following in the console:

-1

Right, I saw the same error when you put an address that does not exist, the ideal is to do as you have mentioned catch the error