Lately, one of my tasks has been to automate regression tests on one of our apps. Since this is a web app, we are using Selenium. Here, I enumerate the steps to configure Firefox for file downloading using Selenium and JUnit by foregoing the downloads dialog box.

Setting up the profile

We will create a new profile to be used for testing. A profile is simply a set of configuration that Firefox will use when you start it. You can use your existing profile as well, but I opted to create a new one so that the Firefox instance for testing will be as pristine as possible (i.e. no unnecessary plugins, no bookmarks, etc). A note: I am working on a Windows machine.

  1. Bring up the command prompt and start the profile chooser by typing in firefox.exe -ProfileManager -no-remote
  2. Click on Create Profile.
  3. Enter the profile name you wish to use. I suggest you include the name of your project instead of just naming it “Test”.
  4. Click on Choose Folder and navigate to the folder where you wish to store the profile files. Make sure you can access that folder easily; write the path down because you will need this in JUnit.
  5. Click on Finish.
  6. You will be brought back to the profile chooser dialog. Click on the Don't ask at start-up checkbox

Note: To make Firefox use your original configurations when you are browsing, bring up the profile chooser dialog, choose the profile named default, and start Firefox.

Configuring Firefox

Now we will configure Firefox to behave like how we want it to.

  1. From the profile chooser dialog, highlight your test profile and click the Start Firefox button.
  2. (Optional if Firefox is not your default browser) Uncheck Always perform this check when starting Firefox.
  3. Click on Tools > Options. We will go through the steps for each tab in the Options dialog box.
  4. General tab
    • Under Startup, choose Show a blank page from the When Firefox starts dropdown.
    • Under Downloads, uncheck the Show the Downloads window when downloading a file checkbox.
    • Still under Downloads, click on Browse for the Save files to option. Navigate to the folder where you want Firefox to put downloaded files. Take note of this folder as well because we will use this in JUnit.
  5. Tabs tab
    • Uncheck Open new windows in a new tab instead and uncheck all warnings.
  6. Content tab
    • Uncheck Block pop-up windows.
  7. (Optional) Privacy tab
    • Under History, choose Never remember history from the Firefox will: dropdown.
  8. Advanced tab
    • Under the General sub-tab, uncheck Use autoscrolling and uncheck Always check to see if Firefox is the default browser on startup.
    • If you will be using a proxy server, choose the Network sub-tab and input your proxy settings there.

Adding MIME Types

Now we need to tell Firefox how to handle downloading each specific type of file.

  1. Navigate to the folder where you saved your custom profile and open the mimeTypes.rdf file in a text editor.
  2. Add the following lines towards the end of the file, right above the closing </RDF:RDF> tag.

     <RDF:Seq RDF:about="urn:mimetypes:root">
         <RDF:li RDF:resource="urn:mimetype:text/plain"/>
     <RDF:Description RDF:about="urn:mimetype:handler:text/plain" NC:alwaysAsk="false" NC:saveToDisk="true">
         <NC:externalApplication RDF:resource="urn:mimetype:externalApplication:text/plain"/>
     <RDF:Description RDF:about="urn:mimetype:text/plain" 
                      NC:value="text/plain" NC:editable="true" NC:fileExtensions="txt" NC:description="Text Document">
         <NC:handlerProp RDF:resource="urn:mimetype:handler:text/plain"/>

    What we did there is we told Firefox to directly download files with MIME type text/plain. If you need to test downloading other file types like .doc or .pdf, you would need to add their MIME types to this file too.

  3. There are two ways to add MIME types to the mimeTypes.rdf file.
    • Via the Firefox Applications GUI
      • From Firefox, choose Tools > Options > Applications
      • If you have previously downloaded a file of the required MIME type, look for it in the list. In the dropdown menu on the right, under Action choose Save File.
      • If the MIME type you want is not in the list, you would need to go to a website that allows you to download a sample file. If the file downloads automatically without showing the download pop-up, you would not have to do anything. If the pop-up shows up, activate the Save File radio button and check the Do this automatically for files like this from now on checkbox and click Okay.
    • Manually editing the file
      • Note: This is generally not the advised way to edit the file due to its complexity. Care is required!
      • Open the mimeTypes.rdf file.
      • Look for the RDF:Seq node and add your desired MIME type.

           <RDF:Seq RDF:about="urn:mimetypes:root">
             <RDF:li RDF:resource="urn:mimetype:text/plain"/>
             <RDF:li RDF:resource="urn:mimetype:application/pdf"/>
      • Add the RDF: Description nodes for that MIME type.

         <RDF:Description RDF:about="urn:mimetype:application/pdf" NC:fileExtensions="pdf" NC:description="Adobe Acrobat Document" NC:value="application/pdf" NC:editable="true">
           <NC:handlerProp RDF:resource="urn:mimetype:handler:application/pdf"/>
         <RDF:Description RDF:about="urn:mimetype:handler:application/pdf" NC:saveToDisk="true" NC:alwaysAsk="false" />

To use this profile in our Selenium test:

FirefoxProfile profile = new FirefoxProfile(new File("path/to/your/profile"));

// We can also set the download folder via code
File testFile = new File("path/to/download/folder");
String downloadFolder = testFile.getAbsolutePath();
profile.setPreference("", downloadFolder);

WebDriver driver = new FirefoxDriver(profile);

And you’re done. :)