Upgrading WebdriverJs to Selenium 3

Yes, I know that Selenium 3 has been out for a while, but I’ve finally got around at looking at updating our end-to-end tests to use it. Newer versions of Firefox require Geckodriver which require Selenium 3.3+ so it’s a forced upgrade of sorts.

Continue reading “Upgrading WebdriverJs to Selenium 3”

Checking web element styles using WebDriverJs

I try to avoid incorporating any or layout/style based checks or locators into my automated end to end tests since these typically change more often leading to a higher test maintenance burden.

But I did have a circumstance recently where I wanted to check that a change I dynamically made to a page was reflected in the resultant web element’s style.

Continue reading “Checking web element styles using WebDriverJs”

Checking an image is actually visible in WebDriverJs

I recently discovered a gap in one of my e2e automated tests where I was checking the existence of an uploaded image in the DOM, but not that the image was actually displayed.

driver.isElementPresent( By.css( `img[alt='upload.jpg']` ) ).then( function( present ) {
  assert.equal( present, true, 'Image not displayed' );
} );

If the DOM has a reference to the image, but it isn’t actually rendered this test will pass. This isn’t ideal.

I remembered my post about how to check that an image is actually rendered using WebDriver in C# and so I used the same JavaScript script which WebDriverJs sends to the driver:

driver.findElement( By.css( `img[alt='upload.jpg']` ) ).then( function( element ) {
  driver.executeScript( 'return (typeof arguments[0].naturalWidth!=\"undefined\" && arguments[0].naturalWidth>0)', element ).then( function( present ) {
    assert.equal( present, true, 'Image not displayed' );
  } );
} );

This works a treat. I’ve moved it into a helper function so I can use this anywhere without repeating it also.

Testing end-to-end with Mocha

As part of my excellent Excellence Wrangler role at Automattic, one of my key tasks has been establishing some end-to-end tests for WordPress.com using Mocha with WebDriverJs. Our testing pyramid doesn’t look much like a pyramid:

wordpress.com test pyramid.png

We’ve got lots of React unit tests at the bottom: these are to speed development.

We’re intentionally missing a middle: the REST API we consume has its own unit tests, we don’t need integration tests for it. We don’t have detailed full stack acceptance tests of our UI: these are too slow and brittle.

We have a handful of e2e flow tests at the top, these are to protect the user experience, we run these on every deployment and frequently in production. These can be brittle on such a fast moving code base, but we limit their number (depth) so they still give us good confidence everything is working well together but limiting our overhead.

So what do these end-to-end tests look like?

I hadn’t used Mocha before and I was used to writing end-to-end tests in Gherkin format in tools like Cucumber and Specflow so I initially began writing end-to-end tests that looked like this:

test.describe('WordPress.com Sign Up', function() {
  test.beforeEach(function() {
    driver.manage().deleteAllCookies();
  });

  test.it('Can Create A Free Blog', function() {
    var signupFlow = new SignUpFlow( driver, 'desktop' );
    signupFlow.createFreeBlog( 'en' );
  });

  test.it('Can Create A New Site With a Paid Domain Upgrade', function() {
    var signupFlow = new SignUpFlow( driver, 'desktop' );
    signupFlow.CreateSiteWithDomainPaidByCreditCard( 'en' );
  });
});

I was pushing the code down into flow classes which I have used before, but the issue with this was the output I was getting from Mocha wasn’t very rich:

WordPress.com Sign Up
      ✓ Can Create A Free Blog
      ✓ Can Create A New Site With a Paid Domain Upgrade

I then realized by looking at an end-to-end test written by another developer that you can nest describe and it statements to give you much more expressive end-to-end tests.

test.describe( `Sign Up (${screenSize})`, function() {

  test.describe( 'Free Site:', function() {
    test.before( 'Delete Cookies and Local Storage', function() {
      driverManager.clearCookiesAndDeleteLocalStorage( driver );
    } );

    test.describe( 'Sign up for a free site', function() {

      test.describe( 'Step One: Themes', function() {
        test.before( 'Can see the choose a theme page as the starting page', function() {
          this.chooseAThemePage = new ChooseAThemePage( driver, { visit: true } );
          return this.chooseAThemePage.displayed().then( ( displayed ) => {
            assert.equal( displayed, true, 'The choose a theme start page is not displayed' );
          } );
        } );

        test.it( 'Can select the first theme', function() {
          return this.chooseAThemePage.selectFirstTheme();
        } );
      } );

      test.describe( 'Step Two: Domains', function() {
        test.before( 'Can then see the domains page ', function() {
          this.findADomainComponent = new FindADomainComponent( driver );
          return this.findADomainComponent.displayed().then( ( displayed ) => {
            assert.equal( displayed, true, 'The choose a domain page is not displayed' );
          } );
        } );

        test.it( 'Can search for a blog name', function() {
          return this.findADomainComponent.searchForBlogNameAndWaitForResults( blogName );
        } );

        test.it( 'Can see a free WordPress.com blog address in results ', function() {
          return this.findADomainComponent.freeBlogAddress().then( ( actualAddress ) => {
            assert.equal( actualAddress, expectedBlogAddress, 'The expected free address is not shown' )
          } );
        } );

        test.it( 'Can select the free address', function() {
          return this.findADomainComponent.selectFreeAddress();
        } );
      } );

This gives us rich feedback:

Sign Up (desktop)
    Free Site:
      Sign up for a free site
        Step One: Themes
          ✓ Can see the choose a theme page as the starting page
          ✓ Can select the first theme
        Step Two: Domains
          ✓ Can then see the domains page
          ✓ Can search for a blog name
          ✓ Can see a free WordPress.com blog address in results
          ✓ Can select the free address

The mistake I had made which I didn’t realize was not creating enough nesting, instead of having Step One, Step Two etc. next to one another, they should be nested within each other. This is because if they’re next to one another, Mocha will run the Step Two, Step Three etc. even if Step One has failed, which is not what we want in an end-to-end scenario where each step is dependent on the previous one.

So, it now looks something like this:

test.describe( 'Free Site:', function() {
    test.before( 'Delete Cookies and Local Storage', function() {
      driverManager.clearCookiesAndDeleteLocalStorage( driver );
    } );

    test.describe( 'Sign up for a free site', function() {
      test.describe( 'Step One: Themes', function() {
        test.before( 'Can see the choose a theme page as the starting page', function() {
          this.chooseAThemePage = new ChooseAThemePage( driver, { visit: true } );
          return this.chooseAThemePage.displayed().then( ( displayed ) => {
            assert.equal( displayed, true, 'The choose a theme start page is not displayed' );
          } );
        } );

        test.it( 'Can select the first theme', function() {
          return this.chooseAThemePage.selectFirstTheme();
        } );

        test.describe( 'Step Two: Domains', function() {
          test.before( 'Can then see the domains page ', function() {
            this.findADomainComponent = new FindADomainComponent( driver );
            return this.findADomainComponent.displayed().then( ( displayed ) => {
              assert.equal( displayed, true, 'The choose a domain page is not displayed' );
            } );
          } );

          test.it( 'Can search for a blog name', function() {
            return this.findADomainComponent.searchForBlogNameAndWaitForResults( blogName );
          } );

          test.it( 'Can see a free WordPress.com blog address in results ', function() {
            return this.findADomainComponent.freeBlogAddress().then( ( actualAddress ) => {
              assert.equal( actualAddress, expectedBlogAddress, 'The expected free address is not shown' )
            } );
          } );

          test.it( 'Can select the free address', function() {
            return this.findADomainComponent.selectFreeAddress();
          } );

          test.describe( 'Step Three: Plans', function() {

which means the output is slightly different but still very useful:

Sign Up (mobile)
  Free Site:
    Sign up for a free site
      Step One: Themes
        ✓ Can select the first theme
        Step Two: Domains
          ✓ Can search for a blog name
          ✓ Can see a free WordPress.com blog address in results
          ✓ Can select the free address
          Step Three: Plans
            ✓ Can select the free plan

These tests are much better written this way. The only issue I am left facing with Mocha is when a before hook fails (such as logging in) the generic afterEach hook we have to take screenshots is not triggered (this is only triggered when an it block is run.

Waiting for AJAX calls in WebDriver C#

I was trying to work out how to wait for AJAX calls to complete in C# WebDriver before continuing a test.

Whilst I believe that your UI should visually indicate that AJAX activity is occurring (such as a spinner) and in this case you should be able to wait until such an indicator changes, if you don’t have a visual indicator and you use JQuery for your AJAX calls, you can use a JavaScript call to jQuery.active to determine if there are any active AJAX requests, and wait until this value is zero.

I wrapped this into a WebDriver extension method on Driver, so you can call it like this:

Driver.FindElement(By.Id("name")).Set("Alister");
Driver.WaitForAjax();
Driver.FindElement(By.Id("next")).Click();

The actual extension method looks like this:

public static void WaitForAjax(this IWebDriver driver, int timeoutSecs = 10, bool throwException=false)
{
  for (var i = 0; i < timeoutSecs; i++)
  {
    var ajaxIsComplete = (bool)(driver as IJavaScriptExecutor).ExecuteScript("return jQuery.active == 0");
    if (ajaxIsComplete) return;
    Thread.Sleep(1000);
  }
  if (throwException)
  {
    throw new Exception("WebDriver timed out waiting for AJAX call to complete");
  }
}

I hope you find this helpful if you’re ever in the same situation.

Five automated acceptance test anti-patterns

Whilst being involved with lots of people writing automated acceptance tests using tools like SpecFlow and WebDriver I’ve seen some ‘anti-patterns’ emerge that can make these tests non-deterministic (flaky), very fragile to change and less efficient to run.

Here’s five ‘anti-patterns’ I’ve seen and what you can do instead.

Anti-pattern One: Not using page-objects

Page objects are just a design pattern to ensure automated UI tests use reusable, modular code. Not using them, eg, writing WebDriver code directly in step definitions, means any changes to your UI will require updates in lots of different places instead of the one ‘page’ class.

Bad

[When(@"I buy some '(.*)' tea")]
public void WhenIBuySomeTea(string typeOfTea)
{
Driver.FindElement(By.Id("tea-"+typeOfTea)).Click();
Driver.FindElement(By.Id("buy")).Click();
}

Better

[When(@"I buy some '(.*)' tea")]
public void WhenIBuySomeTea(string typeOfTea)
{
     MenuPage.BuyTea(typeOfTea);
}

Complicated set up scenarios within the tests themselves

Whilst there’s a place for automated end-to-end scenarios (I call these user journies), I prefer most acceptance tests to jump straight to the point.

Bad

Scenario: Accept Visa and Mastercard for Australia
 Given I am on the home page for Australia
 And I choose the tea menu
 And I select some 'green tea'
 And I add the tea to my basket
 And I choose to checkout
 Then I should see 'visa' is accepted
 And I should see 'mastercard' is accepted

Better

This usually requires adding some special functionality to your app, but the ability for testing to ‘jump’ to certain pages with data automatically set up makes automated tests much easier to read and maintain.

Scenario: Accept Visa and Mastercard for Australia
 Given I am the checkout page for Australia
 Then I should see 'visa' is accepted
 And I should see 'mastercard' is accepted

Using complicated x-path or CSS selectors

Using element identification selectors that have long chains from the DOM in them leads to fragile tests, as any change to that chain in the DOM will break your tests.

Bad

private static readonly By TeaTypeSelector =
            By.CssSelector(
                "#input-tea-type > div > div.TeaSearchRow > div.TeaSearchCell.no > div:nth-child(2) > label");

Better

Identify by ‘id’ (unique) or ‘class’. If there’s multiple elements in a group, create a parent container and iterate through them.

private static readonly By TeaTypeSelector = By.Id("teaType");

Directly executing JavaScript

Since WebDriver can directly execute any arbitrary JavaScript, it can be tempting to bypass DOM manipulation and just run the JavaScript.

Bad

public void RemoveTea(string teaType)
{
  (driver as IJavaScriptExecutor).ExecuteScript(string.Format("viewModel.tea.types.removeTeaType(\"{0}\");", teaType));
  }

Better

It is much better to let the WebDriver control the browser elements which should fire the correct JavaScript events and call the JavaScript, as that way you avoid having your ‘test’ JavaScript in sync to your ‘real’ JavaScript.

public void RemoveTea(string teaType)
{
  driver.FindElement(By.Id("remove-"+teaType)).Click();
}

Embedding implementation detail in your features/scenarios

Acceptance test scenarios are meant to convey intention over implementation. If you start seeing things like URLs in your test scenarios you’re focusing on implementation.

Bad


 Scenario: Social media links displayed on checkout page
   Given I am the checkout page for Australia
   Then I should see a link to 'http://twitter.com/beautifultea'
   And I should see a link to 'https://facebook.com/beautifultea'
 

Better

Hide implementation detail in the steps (or pages, or config) and make your scenarios about the test intention.


 Scenario: Social media links displayed on checkout page
   Given I am the checkout page for Australia
   Then I should see a link to the Beautiful Tea Twitter account
   And I should see a link to the Beautiful Tea Facebook page
 

I hope you’ve enjoyed these anti-patterns. Leave a comment below if you have any of your own.