When I run my Appium script I am getting error "TypeError [ERR_INVALID_ARG_TYPE]" which I am not able to understand

Question

I wrote a script to automate my app using appium with java-script(nodejs), but when I run it I am getting error.

This is the code which I have written.

var webdriverio = require('webdriverio'); 
var except = require('chai').expect; 
var config = require(
{
 port: 4723,
 desiredCapabilities: {
   platformName: "Android",
   platformVersion: "8.1.0",
   deviceName: "00b8afc289da4196",
   app: "/home/user/auto_test/xxx.apk",
   automationName: "UiAutomator2"
  }
}); 
const client = webdriverio.remote(config);

//addition testing 
describe("Simple cases", function () {
  before(function () { 
    this.timeout(50000);
    return client.init();
});
afterEach(function(){
    this.timeout(50000);
    return client.init();
});
describe("test-signup", function(){

    it("signup_click", function(){
    client
        .click('android=new UiSelector().resourceId("com.xxx.xxx:id/txt_log_in")')      
    });
});
after(function() {
return client.end(); 
  });
});

And this is the error which I am getting.

2019-01-02T11:49:15.769Z DEBUG wdio-config: wdio-sync not found, running tests asynchronous
TypeError [ERR_INVALID_ARG_TYPE]: The "id" argument must be of type string. Received type object
at Module.require (internal/modules/cjs/loader.js:653:11)
at require (internal/modules/cjs/helpers.js:22:18)
at Object.<anonymous> (/home/user/automation/tile2.js:3:14)
at Module._compile (internal/modules/cjs/loader.js:723:30)
at Object.Module._extensions..js (internal/modules/cjs/loader.js:734:10)
at Module.load (internal/modules/cjs/loader.js:620:32)
at tryModuleLoad (internal/modules/cjs/loader.js:560:12)
at Function.Module._load (internal/modules/cjs/loader.js:552:3)
at Function.Module.runMain (internal/modules/cjs/loader.js:776:12)
at executeUserCode (internal/bootstrap/node.js:342:17)

Answer 1

The error message tells you that the problem is at line 3, with the require call.

at Module.require (internal/modules/cjs/loader.js:653:11)

at require (internal/modules/cjs/helpers.js:22:18)

at Object. (/home/user/automation/tile2.js:3:14)

When you initialize the config variable, you do not need to call the require function. Check the example here, the relevant part:

// javascript
const opts = {
  port: 4723,
  desiredCapabilities: {
    platformName: "Android",
    platformVersion: "8.0",
    deviceName: "Android Emulator",
    app: "/path/to/the/downloaded/ApiDemos.apk",
    automationName: "UiAutomator2"
  }
};

const client = wdio.remote(opts);

and what you have is:

var config = require(
{
 port: 4723,
 desiredCapabilities: {
   platformName: "Android",
   platformVersion: "8.1.0",
   deviceName: "00b8afc289da4196",
   app: "/home/user/auto_test/xxx.apk",
   automationName: "UiAutomator2"
  }
}); 
const client = webdriverio.remote(config);

So all in all remove the require call from line 3 and leave the rest.