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Hanging promise canceled

I'm trying to set Cloudflare's workers to track the circulation of some ERC20 tokens as an exercise to learn web3 and wasm. Thought it could be simple enough, but about 90% of the time so far has been trying to solve this elusive error
A hanging Promise was canceled. This happens when the worker runtime is waiting for a Promise from JavaScript to resolve but has detected that the Promise cannot possibly ever resolve because all code and events related to the Promise's request context have already finished.
I look for additional information online, but it seems my error is from a different type(?).
Here's a simple snippet of code to reproduce.
mod erc20_abi;
use erc20_abi::ERC20_ABI;
use cfg_if::cfg_if;
use ethers::{
contract::Contract,
core::{abi::Abi, types::Address},
prelude::{AbiError, U256},
providers::{Http, Provider},
};
use num_format::{Locale, ToFormattedString};
use std::convert::TryFrom;
use wasm_bindgen::prelude::*;
cfg_if! {
// When the `wee_alloc` feature is enabled, use `wee_alloc` as the global
// allocator.
if #[cfg(feature = "wee_alloc")] {
extern crate wee_alloc;
#[global_allocator]
static ALLOC: wee_alloc::WeeAlloc = wee_alloc::WeeAlloc::INIT;
}
}
#[wasm_bindgen]
pub async fn handle() -> String {
let web3_ethereum = Provider::<Http>::try_from(WEB3_URL_ETHEREUM).unwrap();
let abi: Abi = serde_json::from_str(ERC20_ABI).unwrap();
let token_contract_ethereum = Contract::new(parse_address(ADDRESS_ETH),
abi, web3_ethereum);
let convert_wei_to_decimal = |bignumber: U256| -> String {
(bignumber.as_u128() / u128::pow(10, 18)).to_formatted_string(&Locale::en)
};
// I believe this is the problem, since just returning a String works fine.
let total_supply_ethereum = token_contract_ethereum
.method::<_, U256>("totalSupply", ())
.unwrap()
.call()
.await
.unwrap();
convert_wei_to_decimal(total_supply_ethereum)
}
fn parse_address(address: &str) -> Address {
address.parse::<Address>().unwrap()
}
This is the worker/workers.js file
addEventListener('fetch', (event) => {
event.respondWith(handleRequest(event.request))
})
const { handle } = wasm_bindgen;
const instance = wasm_bindgen(wasm);
/**
* Fetch and log a request
* #param {Request} request
*/
async function handleRequest(request) {
await instance;
const output = await handle();
let res = new Response(output, { status: 200 });
res.headers.set('Content-type', 'text/html');
return res;
}
Cargo.toml
[package]
name = "circulating-supply"
version = "0.1.0"
license = "GPL-3.0-or-later"
edition = "2018"
# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
[lib]
crate-type = ["cdylib", "rlib"]
[profile.release]
opt-level = 's' # Optimize for size.
lto = true
panic = "abort"
codegen-units = 1
[dependencies]
ethers = { git = "https://github.com/gakonst/ethers-rs" }
serde_json = "1.0.68"
num-format = "0.4.0"
cfg-if = "1.0.0"
wee_alloc = { version = "0.4.5", optional = true }
wasm-bindgen = "0.2.78"
wasm-bindgen-futures = "0.4.28"
js-sys = "0.3.55"
wrangler dev will compile it fine, but going to http://127.0.0.1:8787 will result in Error 1101

In my case a dependency used sth. not available in wasm runtime.
I guess ethers cryptography dependencies also depend on sth. like getrandom.
Adding this to Cargo.toml solved my issue.
[target.wasm32-unknown-unknown.dependencies]
getrandom = { version = "0.1", features = ["wasm-bindgen"] }
This will force your dependencies based on getrandom use the wasm features of getrandom.

require node-pty results in TypeError: Object.setPrototypeOf: expected an object or null, got undefined

TL;DR: If I try to do var pty = require('node-pty'); results in TypeError: Object.setPrototypeOf: expected an object or null, got undefined keep reading for context
Hi, I'm trying to build a proof of concept by creating a terminal using React. For that, I used xterm-for-react which I made it work fine, and node-pty with this last library is with the one I'm having problems.
Initially I created a file in which I would try to make calls to it, it looks like this:
var os = require('os');
var pty = require('node-pty');
var shell = os.platform() === 'win32' ? 'powershell.exe' : 'bash';
var ptyProcess;
function createNewTerminal(FE){
ptyProcess = pty.spawn(shell, [], {
name: 'xterm-color',
cols: 80,
rows: 30,
cwd: process.env.HOME,
env: process.env
});
ptyProcess.onData((data) => FE.write(data));
}
function writeOnTerminal(data){
ptyProcess.write(data);
}
module.exports = {
createNewTerminal,
writeOnTerminal
}
I know it may not be the best code out there, but I was doing it just to try to see if this was possible. My plan was to call the functions from the react component like this:
import {createNewTerminal, writeOnTerminal} from './terminal-backend';
function BashTerminal() {
const xtermRef = React.useRef(null)
React.useEffect(() => {
// You can call any method in XTerm.js by using 'xterm xtermRef.current.terminal.[What you want to call]
xtermRef.current.terminal.writeln("Hello, World!")
createNewTerminal(xtermRef.current.terminal)
}, [])
const onData = (data) => {
writeOnTerminal(data);
}
return (
<XTerm ref={xtermRef} onData={onData}/>
);
}
But I was surprised that this was not working, and returned the error in the title. So, in order to reduce noise, I tried to change my functions to just console logs and just stay with the requires. My file now looked like this:
var os = require('os');
var pty = require('node-pty');
function createNewTerminal(FE){
console.log("Creating new console");
}
function writeOnTerminal(data){
console.log("Writing in terminal");
}
module.exports = {
createNewTerminal,
writeOnTerminal
}
Still got the same error. I'm currently not sure if this is even possible to do, or why this error occurs. Trying to look things online doesn't give any results, or maybe it does and I'm just not doing it right. Well, thanks for reading, I'm completely lost, so, if someone knows something even if it's not the complete answer I will be very thankful

Connecting to a running process in Winappdriver using Javascript

I am fairly new to JS/Winappdriver.
The application I am trying to test is a windows based "Click Once" application from .Net, so I have to go to a website from IE and click "Install". This will open the application.
Once the application is running, I have no way to connect the application to perform my UI interactions while using JavaScript.
Using C#, I was looping through the processes looking for a process name, get the window handle, convert it to hex, add that as a capability and create the driver - it worked. Sample code below,
public Setup_TearDown()
{
string TopLevelWindowHandleHex = null;
IntPtr TopLevelWindowHandle = new IntPtr();
foreach (Process clsProcess in Process.GetProcesses())
{
if (clsProcess.ProcessName.StartsWith($"SomeName-{exec_pob}-{exec_env}"))
{
TopLevelWindowHandle = clsProcess.Handle;
TopLevelWindowHandleHex = clsProcess.MainWindowHandle.ToString("x");
}
}
var appOptions = new AppiumOptions();
appOptions.AddAdditionalCapability("appTopLevelWindow", TopLevelWindowHandleHex);
appOptions.AddAdditionalCapability("ms:experimental-webdriver", true);
appOptions.AddAdditionalCapability("ms:waitForAppLaunch", "25");
AppDriver = new WindowsDriver<WindowsElement>(new Uri(WinAppDriverUrl), appOptions);
AppDriver.Manage().Timeouts().ImplicitWait = TimeSpan.FromSeconds(60);
}
How do I do this in Javascript ? I can't seem to find any code examples.
Based on an example from this repo, I tried the following in JS to find the process to latch on to but without luck.
import {By2} from "selenium-appium";
// this.appWindow = this.driver.element(By2.nativeAccessibilityId('xxx'));
// this.appWindow = this.driver.element(By2.nativeXpath("//Window[starts-with(#Name,\"xxxx\")]"));
// this.appWindow = this.driver.elementByName('WindowsForms10.Window.8.app.0.13965fa_r11_ad1');
// thisappWindow = this.driver.elementByName('xxxxxxx');
async connectAppDriver(){
await this.waitForAppWindow();
var appWindow = await this.appWindow.getAttribute("NativeWindowHandle");
let hex = (Number(ewarpWindow)).toString(16);
var currentAppCapabilities =
{
"appTopLevelWindow": hex,
"platformName": "Windows",
"deviceName": "WindowsPC",
"newCommandTimeout": "120000"
}
let driverBuilder = new DriverBuilder();
await driverBuilder.stopDriver();
this.driver = await driverBuilder.createDriver(currentEwarpCapabilities);
return this.driver;
}
I keep getting this error in Winappdriver
{"status":13,"value":{"error":"unknown error","message":"An unknown error occurred in the remote end while processing the command."}}
I've also opened this ticket here.
It seems like such an easy thing to do, but I couldn't figure this one out.
Any of nodes packages I could use to get the top level window handle easily?
I am open to suggestions on how to tackle this issue while using JavaScript for Winappdriver.

Hope this helps some one out there,
Got around this by creating an exe using C# that generated hex of the app to connect based on the process name, it looks like something like this.
public string GetTopLevelWindowHandleHex()
{
string TopLevelWindowHandleHex = null;
IntPtr TopLevelWindowHandle = new IntPtr();
foreach (Process clsProcess in Process.GetProcesses())
{
if (clsProcess.ProcessName.StartsWith(_processName))
{
TopLevelWindowHandle = clsProcess.Handle;
TopLevelWindowHandleHex = clsProcess.MainWindowHandle.ToString("x");
}
}
if (!String.IsNullOrEmpty(TopLevelWindowHandleHex))
return TopLevelWindowHandleHex;
else
throw new Exception($"Process: {_processName} cannot be found");
}
Called it from JS to get the hex of the top level window handle, like this,
async getHex () {
var pathToExe =await path.join(process.cwd(), "features\\support\\ProcessUtility\\GetWindowHandleHexByProcessName.exe");
var pathToDir =await path.join(process.cwd(), "features\\support\\ProcessUtility");
const result = await execFileSync(pathToExe, [this.processName]
, {cwd: pathToDir, encoding: 'utf-8'}
, async function (err, data) {
console.log("Error: "+ err);
console.log("Data(hex): "+ data);
return JSON.stringify(data.toString());
});
return result.toString().trim();
}
Used the hex to connect to the app like this,
async connectAppDriver(hex) {
console.log(`Hex received to connect to app using hex: ${hex}`);
const currentAppCapabilities=
{
"browserName": '',
"appTopLevelWindow": hex.trim(),
"platformName": "Windows",
"deviceName": "WindowsPC",
"newCommandTimeout": "120000"
};
const appDriver = await new Builder()
.usingServer("http://localhost:4723/wd/hub")
.withCapabilities(currentAppCapabilities)
.build();
await driver.startWithWebDriver(appDriver);
return driver;
}

Solution:
In WebDriverJS (used by selenium / appium), use getDomAttribute instead of getAttribute. Took several hours to find :(
element.getAttribute("NativeWindowHandle")
POST: /session/270698D2-D93B-4E05-9FC5-3E5FBDA60ECA/execute/sync
Command not implemented: POST: /session/270698D2-D93B-4E05-9FC5-3E5FBDA60ECA/execute/sync
HTTP/1.1 501 Not Implemented
let topLevelWindowHandle = await element.getDomAttribute('NativeWindowHandle')
topLevelWindowHandle = parseInt(topLevelWindowHandle).toString(16)
GET /session/DE4C46E1-CC84-4F5D-88D2-35F56317E34D/element/42.3476754/attribute/NativeWindowHandle HTTP/1.1
HTTP/1.1 200 OK
{"sessionId":"DE4C46E1-CC84-4F5D-88D2-35F56317E34D","status":0,"value":"3476754"}
and topLevelWindowHandle have hex value :)

Using `filter` lambda in gremlin with javascript

I am using OrientDb with JavaScript and I have tried with startingWith, containing, endingWith, notContaining, notEndingWith, notStartingWith predicates unsuccessfully. Maybe is a wrong implementation from my side but I have not found documentation about how to use.
I've been looking for a way to filter with lambdas to get a sql like behavior but have not been successful. I tried to use the method described in this answer, but it is not working on JavaScript. When using the predicates the answer is an error.
I've tried that too:
What is the equivalent of the gremlin queries in gremlin javascript?
My current JavaScript code:
import * as gremlin from 'gremlin';
const traversal = gremlin.process.AnonymousTraversalSource.traversal;
const DriverRemoteConnection = gremlin.driver.DriverRemoteConnection;
const TextPredicated = gremlin.process.TextP;
const authenticator = new gremlin.driver.auth.PlainTextSaslAuthenticator('usr', 'pwd');
const remote = new DriverRemoteConnection(
'ws://localhost:8182/gremlin', {
authenticator,
traversalSource: 'g'
});
remote.addListener('socketError', (error) => { console.log(`socketError: ${error}`); });
(async () => {
try {
remote.open();
const g = await traversal().withRemote(remote);
const results = await g.V()
.where('username', TextPredicated.containing('john'))
.toList();
console.log(results);
remote.close();
} catch (error) {
console.log(error);
} finally {
remote.close();
}
})();

You don't say what your error is, but I think your Gremlin should use has() rather than where():
const results = await g.V()
.has('username', TextPredicated.containing('john'))
.toList();
Also note that TextP did not become available until TinkerPop 3.4.0 so you'd need to be sure that your graph (in your case, OrientDB) supports at least this version of TinkerPop.

Does MongoDB Stitch Functions support async/await definitions?

Asynchronous function definitions on MongoDB (Atlas) Stitch display warnings on the GUI editor. Including the example code provided on the reference for Triggers.
The code found here can be was copied over directly to the Stitch Function editor and produces warnings because of the async keyword.
Example code from the docs.
exports = async function (changeEvent) {
// Destructure out fields from the change stream event object
const { updateDescription, fullDocument } = changeEvent;
// Check if the shippingLocation field was updated
const updatedFields = Object.keys(updateDescription.updatedFields);
const isNewLocation = updatedFields.some(field =>
field.match(/shippingLocation/)
);
// If the location changed, text the customer the updated location.
if (isNewLocation) {
const { customerId, shippingLocation } = fullDocument;
const twilio = context.services.get("myTwilioService");
const mongodb = context.services.get("mongodb-atlas");
const customers = mongodb.db("store").collection("customers");
const { location } = shippingLocation.pop();
const customer = await customers.findOne({ _id: customer_id })
twilio.send({
to: customer.phoneNumber,
from: context.values.get("ourPhoneNumber"),
body: `Your order has moved! The new location is ${location}.`
});
}
};
I want to know if Stitch supports the async/await paradigm and if I should be concerned about the warnings shown.

After some testing I found that at this time the async/await keywords cause the linter to throw errors and warnings. This means that for async callbacks it is best to define them separately as it will improve the linting. IE. [].map(async () => {}) will prompt errors that can be worked around.
The runtime execution returns the results as expected from standard asynchronous operations.