自定义函数以选择并单击Nightwatch中的随机元素

Question

I'm new to e2e testing (and JS). I use Nightwatch framework.

I'm trying to create a function that selects a random element from a list of elements with the same selector, and clicks on it.

This is what I tried:

  pickOne(selector, target) {
    this.api.elements(selector, target, function(res) {
       optionsLength = Math.floor((Math.random() * res.value.length) + 1);
    });
    this.api.waitForElementVisible(`${target}:nth-child(${optionsLength})`);
    this.api.click(`${target}:nth-child(${optionsLength}) .action-button`);
  }

But in this case, optionsLength is not defined .

Math.floor((Math.random() * res.value.length) + 1) returns a number. I want to use this number outside of the function.

I've tried to store the full function in a variable, as in:

const optionsLength = this.api.elements(selector, element, function(res) {
       Math.floor((Math.random() * res.value.length) + 1);
    });

But that way optionsLength logs [object Object] instead a number.

Answer 1

Define 2nd and 3rd functions in callback is not good, it would lead to callback hell.

You should use .perform() api instead , it will chain your functions :

pickOne(selector, target) {    
            this.api.elements(selector, target, function(res) {
               optionsLength = Math.floor((Math.random() * res.value.length) + 1);
            })
             .perform(function (client, done) {
                 console.log(optionsLength) ;// ***you can access optionsLength in above function***

                 done();
            })

This is docs from nightwatch Perform

Answer 2

Declaring the function with arrow syntax and wrapping everything into the callback has solved the (scope) issue.

Arrow syntax allows to keep calling this.api.x in the callback.

  pickOne(selector, target) {
     this.api.elements(selector, target, res => {
        optionsLength = Math.floor((Math.random() * res.value.length) + 1);
        this.api.waitForElementVisible(`${target}:nth-child(${optionsLength})`);
        this.api.click(`${target}:nth-child(${optionsLength}) .action-button`);
    });
  }

Answer 3

function postimgname() {
var date = new Date();
var str =$scope.data_user.user_id + "" +date.getFullYear() + "" + (date.getMonth() + 1) + "" + date.getDate() + "" +  date.getHours() + "" + date.getMinutes() + "" + date.getSeconds() 
+ "" + Math.floor(Math.random() * 6) + 1 ;
return str;

}