_python

Example 1

NOTE: You can see the application under test here. It's an example from the-internet. In the example there are 2 tables. We will start with the first table and then work with the second.

We kick things off by pulling in our requisite libraries (import unittest for our test framework and from selenium import webdriver to drive the browser), declare our test class, and wire up some test setUp and tearDown methods.

# filename: tables.py
import unittest
from selenium import webdriver
from selenium.webdriver.common.by import By
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC


class Tables(unittest.TestCase):

    def setUp(self):
        self.driver = webdriver.Firefox()

    def tearDown(self):
        self.driver.quit()

# ...

Here is the markup from the first table example we're working with. Note that it does not have any id or class attributes.

<table id="table1" class="tablesorter">
    <thead>
      <tr>
        <th><span>Last Name</span></th>
        <th><span>First Name</span></th>
        <th><span>Email</span></th>
        <th><span>Due</span></th>
        <th><span>Web Site</span></th>
        <th><span>Action</span></th>
      </tr>
    </thead>
    <tbody>
      <tr>
        <td>Smith</td>
        <td>John</td>
        <td>jsmith@gmail.com</td>
        <td>$50.00</td>
        <td>http://www.jsmith.com</td>
        <td>
          <a href='#edit'>edit</a>
          <a href='#delete'>delete</a>
        </td>
      </tr>

There are 6 columns (Last Name, First Name, Email, Due, Web Site, and Action). Each one is sortable by clicking on the column header. The first click should sort them in ascending order, the second click in descending order.

There is a small sampling of data in the table to work with (4 rows worth). So we should be able to sort the data, grab it, and confirm that it sorted correctly. So lets do that in our first test with the Due column using a CSS Pseudo Class.

# filename: tables.py
# ...
  def test_sort_number_column_in_ascending_order_with_limited_locators(self):
      driver = self.driver
      driver.get('http://the-internet.herokuapp.com/tables')
      WebDriverWait(driver, 20).until(EC.element_to_be_clickable((By.CSS_SELECTOR,'#table1 thead tr th:nth-child(4)'))).click()
      due_column = driver.find_elements(By.CSS_SELECTOR,'#table1 tbody tr td:nth-child(4)')
      dues = [float(due.text.replace('$','')) for due in due_column]
      assert dues == sorted(dues)

# ...

After loading the page we find and click the column heading that we want with a CSS Pseudo-class (e.g. #table1 thead tr th:nth-child(4)). This locator targets the 4th <th> element in the table heading section (e.g., <thead>) (which is the Due column heading).

We then use another pseudo-class to find all <td> elements within the Due column by looking for the 4th <td> of each row in the table body. Once we have them we grab each of their text values, clean them up (.replace('$','')), convert them to a number (flat()), and store them all in a list called dues. We then compare this collection to a sorted version of itself to see if they match. If they do, then the Due column was sorted in ascending order and the test will pass.

If we wanted to test for descending order, we would need to click the Due heading twice after loading the page. Other than that the code is identical except for the assertion which is checking the same thing but reversing the sort order.

# filename: tables.py
# ...
    def test_sort_number_column_in_descending_order_with_limited_locators(self):
        driver = self.driver
        driver.get('http://the-internet.herokuapp.com/tables')
        WebDriverWait(driver, 20).until(EC.element_to_be_clickable((By.CSS_SELECTOR,'#table1 thead tr th:nth-child(4)'))).click()
        WebDriverWait(driver, 20).until(EC.element_to_be_clickable((By.CSS_SELECTOR,'#table1 thead tr th:nth-child(4)'))).click()
        due_column = driver.find_elements(By.CSS_SELECTOR,'#table1 tbody tr td:nth-child(4)')
        dues = [float(due.text.replace('$','')) for due in due_column]
        assert dues == sorted(dues, reverse=True)

# ...

We can easily use this approach to test a different column (e.g., one that doesn't deal with numbers) and see that it gets sorted correctly too. Here's a test that exercises the Email column.

# filename: tables.py
# ...
    def test_sort_text_column_in_ascending_order_with_limited_locators(self):
        driver = self.driver
        driver.get('http://the-internet.herokuapp.com/tables')
        WebDriverWait(driver, 20).until(EC.element_to_be_clickable((By.CSS_SELECTOR,'#table1 thead tr th:nth-of-type(3)'))).click()
        email_column = driver.find_elements(By.CSS_SELECTOR,'#table1 tbody tr td:nth-of-type(3)')
        emails = [email.text for email in email_column]
        assert emails == sorted(emails)

# ...

The mechanism for this is the same as before, except that we don't need to clean the text up or convert it before performing our assertion.

But What About Older Browsers?

Now we have some working tests that will load the page and check sorting for a couple of columns in both ascending and descending order. Great! But if we run these again an older browser (e.g., Internet Explorer 8, etc.) it will throw an exception stating Unable to find element. This is because older browsers don't support CSS Pseudo-classes.

You've come a long way, so it's best to get value out of what you've just written. To do that you can run these tests on current browsers and submit a request to your front-end developers to update the table markup with some semantic class attributes. Later, when these new locators have been implemented on the page, you can revisit these tests and update them accordingly.

Here is markup of what our original table would look like with some helpful attributes added in. It's also the markup from the second table on our application under test.

<table id="table2" class="tablesorter">
    <thead>
      <tr>
        <th><span class='last-name'>Last Name</span></th>
        <th><span class='first-name'>First Name</span></th>
        <th><span class='email'>Email</span></th>
        <th><span class='dues'>Due</span></th>
        <th><span class='web-site'>Web Site</span></th>
        <th><span class='action'>Action</span></th>
      </tr>
    </thead>
    <tbody>
      <tr>
        <td class='last-name'>Smith</td>
        <td class='first-name'>John</td>
        <td class='email'>jsmith@gmail.com</td>
        <td class='dues'>$50.00</td>
        <td class='web-site'>http://www.jsmith.com</td>
        <td class='action'>
          <a href='#edit'>edit</a>
          <a href='#delete'>delete</a>
        </td>
      </tr>

With these new attributes the locators in our sorting tests become a lot simpler and more expressive. Let's write a new Due ascending order test to demonstrate.

# filename: tables.py
# ...
    def test_sort_number_column_in_ascending_order_with_helpful_locators(self):
        driver = self.driver
        driver.get('http://the-internet.herokuapp.com/tables')
        WebDriverWait(driver, 20).until(EC.element_to_be_clickable((By.CSS_SELECTOR,'#table2 thead .dues'))).click()
        due_column = driver.find_elements(By.CSS_SELECTOR,'#table2 tbody .dues')
        dues = [float(due.text.replace('$','')) for due in due_column]
        assert dues == sorted(dues)

if __name__ == "__main__":
    unittest.main()

Not only will these selectors work in current and older browsers, but they are also more resilient to changes in the table layout since they are not using hard-coded numbers that rely on the column order.

Expected Behavior

When we save this file and run it (e.g., python tables.py from the command-line) here is what will happen:

Browser opens
Load the page
Click the column heading
Grab the values for the target column
Assert that the column is sorted in the correct order (ascending or descending depending on the test)
Close the browser

Summary

CSS Pseudo-classes are a great resource and unlock a lot of potential for your tests. They enable a bit of CSS gymnastics but that's only assuming you've come up with a test strategy that rules out older browsers. If you don't have a test strategy or are curious to see how yours compares, check out tip 18.

For more info on CSS Pseudo-classes see this write-up by Sauce Labs, and maybe the W3C spec for CSS3 if you're feeling adventurous. And for a more in-depth walk-through on HTML Table design check out Treehouse's write-up here.

Happy Testing!

Example 1​

But What About Older Browsers?​

Expected Behavior​

Summary​

Example 1

But What About Older Browsers?

Expected Behavior

Summary