How best to test file download links using Selenium

Question

On a website I am testing we have various links that download PDF files to the users computer.

Our selenium suite runs nightly on bamboo, if we were to download the various files overnight it would cause the hard disk to fill up in short order. The Selenium job itself is sandboxed and can't access the file system to delete the file.

What is best practice for testing file downloads with this setup?

A few potential scenarios;

1. Download the file and perform some kind of cron cleanup serverside (this might not be viable).
2. Check the URL of the file location is as expected but don't download the file
3. Click the link and accept the presence of a dialogue box as sufficient coverage (without downloading the file)

Answer 1

Using chrome I automate downloading the file, and then open the chrome://downloads page to retrieve the downloaded files list from shadow DOM like this:

const docs = document
  .querySelector('downloads-manager')
  .shadowRoot.querySelector('#downloads-list')
  .getElementsByTagName('downloads-item');

This solution is restrained to chrome, the data also contains information like file path and download date.

Not sure about data cleanup, I'm currently doing it in Bamboo without problems.

I also use a timeout polling the download results to give the download time to complete.

If testing downloads through the browser is not necessary, then a program to test the website for broken links would do.

Answer 2

I agree with KirbyScope I wouldn't test this with Selenium at all.

I would use an http client to make the necessary requests to authorise and then GET the PDF and then assert on the response and content return to ensure it was a valid PDF.

You could do this either programmatically or with a tool like JMeter (and have your JMeter script run via command line)

Answer 3

@ Adurbe

• load the page with the download link, find the element on the page, click on it.
• driver.findElement(By.id(“foo”)).sendKeys(“AbsoluteFileLocation”);
• < input type="file">
• DELETE the downloaded file
• File downloadedFile = new File(<fileLocation>); downloadedFile.delete();

Answer 4

The best way to handle download functionality and pop-ups, is to use AutoIT with Selenium for testing download/upload files functionality (hope this is what you are asking). This link will provide you step-by-step guidelines over how easily you can use AutoIT with Selenium for such functionalities.

Actually, downloading and uploading files is related to windows/desktop functionality and this is where territory of Selenium shows issues, but with the help of AutoIT (Desktop testing tool) you can handle these windows pop-ups and manage your downloads too.

You will find some information here and over SO, on how you can handle download functionality with Selenium itself (but unfortunately, this didn't work for me, because of my machine issue and so I switched to AutoIT).

Answer 5

What is best practice for testing file downloads? Assert the (static link) URL on click is correct?

Selenium can't interact with anything outside of the browser, unless you incorporate AutoIT like @Dhiman pointed out.

What are you trying to assert here? Is the link working? You could extract the url and hit it, then make sure the response is 200 (OK). Or, just make sure the link is what you expected.