Sauce Labs now supports the W3C WebDriver-compliant capabilities and protocol featured in Selenium versions 3.11 and higher. Please note that some extended capabilities are not backwards-compatible with versions prior to 4.0. This article will help ensure that your tests are W3C WebDriver-compliant and can successfully execute on Sauce Labs. 

We early adopted the W3C WebDriver specification when it achieved the W3C standard level as the automation protocol for web browsers. As browser vendors update to support W3C WebDriver and shift away from JSON Wire Protocol (JWP), it’s important to update your tests accordingly.

See the following sections for more information:

Sauce Labs Web Protocol Support

What You'll Need

To ensure W3C WebDriver compliance, you'll need to:

• Use Selenium version 3.11 or higher.
  
  

• Switch completely from using legacy JWP desired capabilities to the new W3C WebDriver capabilities. Note that their naming conventions are slightly different – for example:
  

  JWP (legacy)	W3C (new)
  platform	platformName
  version	browserVersion

  For more information on W3C WebDriver-compliant capabilities, head to the official W3C recommendation website.
  
  

• Include our custom sauce:options capabilities (e.g., name, build) in your Sauce Labs test scripts, bundled together, as seen in this example:

  browserName: 'firefox', platformName: 'macOS 10.15', browserVersion: 'latest' sauce:options: { name: 'My test name', build: 'My build', username: "SAUCE_USERNAME", accessKey: "SAUCE_ACCESS_KEY" seleniumVersion: "3.141.59" }

  accessKey appiumVersion avoidProxy build captureHtml chromedriverVersion commandTimeout crmuxdriverVersion customData disablePopupHandler extendedDebugging firefoxAdapterVersion firefoxProfileUrl idleTimeout iedriverVersion maxDuration name parentTunnel passed prerun preventRequeue priority proxyHost public recordLogs recordScreenshots recordVideo restrictedPublicInfo screenResolution seleniumVersion source tags timeZone tunnelIdentifier username videoUploadOnPass More information: Test Configuration Options.

Getting Started

Below are a couple of mobile and web test script examples you can use to get up and running quickly:

ChromeOptions chOpts = new ChromeOptions(); 
chOpts.setExperimentalOption("w3c", true);

Verifying Capabilities for W3C WebDriver Compliance

Here's how to verify if your tests are running under the new W3C WebDriver protocol:

1. Go to the Test Details page for your test in Sauce Labs.
2. Click the Commands tab.
3. Select the first Post command, which will be Post /session.
4. Under the Parameters section, check the capabilities that are used in the test. 

• • If your Parameters section begins with capabilities, you're running the new W3C WebDriver-compliant version 
    
    
    
  • If it begins with desiredCapabilities, you're running the legacy, non-W3C WebDriver version 
     

W3C WebDriver-Compliant Language Changes in Selenium 3.11+

There are some changes to specific Selenium language bindings you should be aware of when migrating to the W3C WebDriver protocol. Here is an example:

FireFoxOptions mozOpts = new FirefoxOptions();

DesiredCapabilities caps = new DesiredCapabilities.firefox();

"INFO: Using `new FirefoxOptions()` is preferred to `DesiredCapabilities.firefox()"

MutableCapabilities sauceCaps = new MutableCapabilities();
sauceCaps.setCapability("username", "someuser");
sauceCaps.setCapability("accessKey", "00000000-0000-0000-0000-000000000000");
sauceCaps.setCapability("name", "my test case");

MutableCapabilities caps = new MutableCapabilities();
caps.setCapability("sauce:options", sauceCaps);
caps.setCapability("platformName", "Windows 10");
caps.setCapability("browserName", "firefox");
caps.setCapability("browserVersion", "latest");
        
WebDriver driver = new RemoteWebDriver(new URL("https://ondemand.saucelabs.com/wd/hub"), caps);

DesiredCapabilities caps = new DesiredCapabilities();
caps.setCapability("username", "someuser");
caps.setCapability("accessKey", "00000000-0000-0000-0000-000000000000");
caps.setCapability("name", "my test case");
caps.setCapability("browser", "firefox");
caps.setCapability("platform", "Windows 10");
caps.setCapability("version", "latest");
 
WebDriver driver = new RemoteWebDriver(new URL("https://ondemand.saucelabs.com/wd/hub"), caps);

Instantiating WebDriver with W3C WebDriver-Compliant Capabilities

Select a code snippet below in the programming language of your choice, then follow the instructions. You can find more sample code in the Sauce Labs training repository on GitHub.

Common Test Script Configuration Errors to Avoid

Here are some things to keep in mind when configuring your test script capabilities.

Don't Mix W3C Capabilities with JWP Capabilities

It's important not to mix W3C WebDriver-compliant capabilities with legacy JWP capabilities. This will result in a system error when you're spinning up a WebDriver session:

selenium.common.exceptions.WebDriverException: Message: Misconfigured -- Mixed Capabilities Error.

W3C keys (platformName/browserVersion) were detected alongside JWP keys (platform/version). To fix this, replace all JWP keys with W3C keys.

The following desired capabilities were received:
{'browserName': 'chrome',
 'browserVersion': '80',
 'platform': 'Windows'} 

See https://wiki.saucelabs.com/display/docs/w3c+capabilities+support for more details.

To fix this particular error, you'd need to change platform to platformName and then change version to browserVersion:

browserName: 'chrome',
platformName: 'Windows',
browserVersion: '80'
sauce:options: {
  name: 'My test name',
  build: 'My build',
  username: "SAUCE_USERNAME",
  accessKey: "SAUCE_ACCESS_KEY"
  seleniumVersion: "3.141.59"
} 

Additional Resources

• Sauce Labs Supports the W3C WebDriver Protocol: run compliant tests on every browser
• Test Configuration Options: Sauce Labs capabilities for Selenium and Appium
• Useable code examples for your tests: public GitHub repo with language-specific bindings that leverage our new sauce:options capability