Protractors, promises, parameters, and closures

问题

I'm now tearing out what little remains of my hair. And I think I've lost vision in my left knee.

I have two functions that work. Each one takes a parameter correctly. I would dearly, so very dearly, love one function to take both parameters.

I have a super simple data structure:

var stuff = [
          { name: "Stone", id: "cc45" },
          { name: "Hanley", id: "cc78" }
      ];

I wish to loop through the structure and run a super simple test on each. Please observe:

  for (var ii = 0; ii < stuff.length; ii++) {
      var aTile = element(by.id(stuff[ii].id));

      aTile.getText().then(
          /* magical solution */
      );
  }

All I'm missing the magical solution. In version A (which lacks magic) I can successfully regard the text that Protractor kindly grabbed:

  aTile.getText().then((function (text) {
      console.log(" --Protractor Grab--" + text);
  }));

In version B (which also lacks magic) I can successfully behold the data I wish to compare the Protractor-grabbed text to:

  aTile.getText().then((function (test) {
      console.log(" ==Stuff test==" + test);
  })(stuff[ii].name));

What I cannot do, no matter how much hair I pull, is to get Protractor to compare both. Effectively, I need to add this:

   expect(protractorGrabbedText).toContain(expectedTextFromStuff);

Please kind heroes of code, help me, I implore you.

回答1:

it's very simple. expect() method have the capability to make a promise to resolve implicitly and use the result to compare with the actual data.You can use something like below,

for (var ii = 0; ii < stuff.length; ii++) {
  var aTile = element(by.id(stuff[ii].id)).getText();
  expect(aTile.getText()).toContain(stuff[ii].name) //This will take care of resolving the promises.
 }

Method -2 :

Since you are using for loop, you need to use closures to get the value of ii inside the promise. try the below code.

for (var ii = 0; ii < stuff.length; ii++) {
    function closure(index){
        element(by.id(stuff[index].id)).getText().then(function(text){
        expect(text). toContain(stuff[index].name)
     })
   }
 closure(ii)
 }

回答2:

I second the above answer. this should work

for (var ii = 0; ii < stuff.length; ii++) {
    var aTile = element(by.id(stuff[ii].id));
    expect(aTile.getText()).toContain(stuff[ii].name)
        }

来源：https://stackoverflow.com/questions/39729393/protractors-promises-parameters-and-closures

标签

javascript

parameters

closures

protractor