i want to connect my rfid Reader with nodejs which is using "COM4" port i used serial port to connect with it but i had this error
node recive.js
(node:10567) UnhandledPromiseRejectionWarning: Error: Error: No such file or directory, cannot open COM4
(node:10567) 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(). To terminate 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: 1)
(node:10567) [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.
the code :
var SerialPort = require("serialport").SerialPort;
var port = "COM4";
var serialPort = new SerialPort({
path: port,
baudRate: 9600
});
serialPort.on("open", function () {
console.log("-- Connection opened --");
serialPort.on("data", function (data) {
console.log("Data received: " + data);
});
});
Related
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(). To terminate 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: 1)
(node:5876) [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.
How to solve this type of error any suggestions
Your code throws an error at some point in some promise. You can solve it by properly handling the exception.
Ex:
var p = new Promise((resolve, reject) => {
// Some code
});
p.then(res => {
// No errors thrown
}).catch(err => {
// Exception happened. Print the error
console.log(err);
});
when am trying to move the image after inserting into mongo db using the function
var db = require('../config/dbconnect')
module.exports = {
//addProduct:(product,callback)=>
addProduct: (product, callback) => {
//console.log(product)
db.get().collection('product').insertOne(product).then((data) => {
console.log(data)
callback(data.ops[0]._id)
})
}
}
I am getting an error like:
{
acknowledged: true,
insertedId: new ObjectId("61054e43cffb994774d37ab0")
}
(node:6964) UnhandledPromiseRejectionWarning: TypeError: Cannot read property '0' of undefined
at E:\Nodejs\ecommerce\helpdesk\product_help.js:11:27
at processTicksAndRejections (internal/process/task_queues.js:95:5)
(Use `node --trace-warnings ...` to show where the warning was created)
(node:6964) 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(). To terminate 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: 1)
(node:6964) [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 is error first callback. Try the second argument which is the result.
db.get().collection('product').insertOne(product).then((error,data)=>
{
console.log(data)
callback(data.ops[0]._id)
})
instead of callback(data.ops[0]._id).
Try:
db.get().collection('product').insertOne(product).then((data) => {
callback(data.insertedId)
})
.catch((err)=>console.log('venk error',err))
}
I am trying to send a string through serialport in node.js with the following code:
function createSerialPort() {
myPort = new SerialPort('COM3', {
baudRate: 115200, dataBits: 8, parity: 'none', stopBits: 1, flowControl: 0
})
myPort.write("135");
}
Everytime I run it it gives me this error:
(node:8468) UnhandledPromiseRejectionWarning: Error: Opening COM3: Access denied
(node:8468) 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(). To terminate 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: 1)
(node:8468) [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
I have looked everywhere for a fix to this (I am new to using serialport) and the only solution I have found is to do this:
function createSerialPort() {
myPort = new SerialPort('COM3', {
baudRate: 115200, dataBits: 8, parity: 'none', stopBits: 1, flowControl: 0
}, true)
myPort.write("135");
}
That solution then gives me this:
(node:18192) UnhandledPromiseRejectionWarning: TypeError: callback.call is not a function
at SerialPort._error (C:\examplepath\node_modules\#serialport\stream\lib\index.js:198:14)
at C:\examplepath\node_modules\#serialport\stream\lib\index.js:242:12
(node:18192) 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(). To terminate 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: 1)
(node:18192) [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.
Hi I'm currently trying to learn and implement some unit testing for my HTTP Requests. currently I have a SQlite db setup, and a simple post request. This is the test I have written so far:
"use strict";
process.env.NODE_ENV = 'test';
const chai = require('chai');
const chaiHttp = require('chai-http');
chai.use(chaiHttp);
const expect = chai.expect;
const app = require('../../../app');
chai.request('http://localhost:8080')
.put('/tempValue')
.send({sensorid: '1', sensorValue: '25.00', timeRecorded: '2020-04-12 12:30'})
.then(function (res) {
expect(res).to.have.status(200);
})
.catch(function (err) {
throw err;
});
I seem to be getting a error that it is unable to open the database file. Currently I am just connecting to the database in the app.js file, using const dbPath = "./database/database.db"; and const dbConnection = sqlite.open(dbPath, { Promise });
I also seem to get errors about incorrect use of .catch? This is the error log:
(node:13952) UnhandledPromiseRejectionWarning: Error: SQLITE_CANTOPEN: unable to open database file
(node:13952) 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(). To terminate the node process on unha
ndled promise rejection, use the CLI flag `--unhandled-rejections=strict` (see https://nodejs.org/api/cli.html#cli_unhandled_rejections_mode). (rejection id: 1)
(node:13952) [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.
(node:13952) UnhandledPromiseRejectionWarning: AssertionError: expected { Object (_events, _eventsCount, ...) } to have status code 200 but got 404
at D:\Uni Work\3rd Year\302CEM - Agile Development\Penguin Project\test\api\temperature\get.js:15:29
at processTicksAndRejections (internal/process/task_queues.js:97:5)
(node:13952) 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(). To terminate the node process on unha
ndled promise rejection, use the CLI flag `--unhandled-rejections=strict` (see https://nodejs.org/api/cli.html#cli_unhandled_rejections_mode). (rejection id: 2)
Thanks for any help!
EDIT:
This is the particular post request I'm testing, it uses MQTT to check if the message being sent is to that topic structure, then inserts into the database.
app.ws.use(route.all('/tempValue', function (ctx){
client.on('message', async function(topic,message){
console.log(topic, message.toString());
if (topic === '302CEM/Penguin/Room1/Temperature'){
const SQL = "INSERT INTO sensorData (sensorid, sensorValue, timeRecorded) VALUES (?,?,?)";
try {
const temptostring = message.toString();
const db = await dbConnection;
await db.run(SQL, ["1",temptostring, moment().format('YYYY-MM-DD HH:mm')]);
ctx.websocket.send(temptostring);
} catch (err) {
console.log(err);
}
}
})
}));
I am trying to set up chrome-launcher to output all console messages to terminal. My code looks like this
const chromeLauncher = require('chrome-launcher');
const CDP = require('chrome-remote-interface');
(async function() {
async function launchChrome() {
return await chromeLauncher.launch({
chromeFlags: [
'--window-size=1200,800',
'--user-data-dir=/tmp/chrome-testing',
'--auto-open-devtools-for-tabs'
]
});
}
const chrome = await launchChrome();
const protocol = await CDP({
port: chrome.port
});
const {
DOM,
Network,
Page,
Runtime,
Console
} = protocol;
await Promise.all([Network.enable(), Page.enable(), DOM.enable(), Runtime.enable(), Console.enable()]).catch(console.log);
// REMARKS: messageAdded is fired every time a new console message is added
Console.messageAdded((result) => {
console.log(result);
});
})();
I copied some of this from the question here: How to get console.log output in Terminal via Headless Chrome Runtime.evaluate
When I try to navigate to a page, none of the console messages show up in the terminal, and the chrome-launcher exits with the following error:
(node:14531) UnhandledPromiseRejectionWarning: Error: connect ECONNREFUSED 127.0.0.1:64656
at TCPConnectWrap.afterConnect [as oncomplete] (net.js:1083:14)
(node:14531) 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:14531) [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.