feat: add PANTHER_REDUCED_MOTION to limit animations

CHANGELOG.md

@@ -1,6 +1,11 @@
 CHANGELOG
 =========
 
+2.2.0
+-----
+
+* Add a `PANTHER_REDUCED_MOTION` environment variable to instruct the website to minimize the amount of non-essential movement
+
 2.1.2
 -----
 

README.md

@@ -366,6 +366,7 @@ The following environment variables can be set to change some Panther's behaviou
 * `PANTHER_ERROR_SCREENSHOT_DIR`: to set a base directory for your failure/error screenshots (e.g. `./var/error-screenshots`)
 * `PANTHER_DEVTOOLS`: to toggle the browser's dev tools (default `enabled`, useful to debug)
 * `PANTHER_ERROR_SCREENSHOT_ATTACH`: to add screenshots mentioned above to test output in junit attachment format
+* `PANTHER_REDUCED_MOTION`: to instruct the website to minimize the amount of non-essential movement
 
 ### Changing the Hostname and Port of the Built-in Web Server
 

src/ProcessManager/ChromeManager.php

@@ -114,6 +114,11 @@ private function getDefaultArguments(): array
             $args[] = '--no-sandbox';
         }
 
+        // Prefer reduced motion, see https://developer.mozilla.org/fr/docs/Web/CSS/@media/prefers-reduced-motion
+        if ($_SERVER['PANTHER_REDUCED_MOTION'] ?? false) {
+            $args[] = '--force-prefers-reduced-motion';
+        }
+
         // Add custom arguments with PANTHER_CHROME_ARGUMENTS
         if ($_SERVER['PANTHER_CHROME_ARGUMENTS'] ?? false) {
             $arguments = explode(' ', $_SERVER['PANTHER_CHROME_ARGUMENTS']);

src/ProcessManager/FirefoxManager.php

@@ -13,6 +13,7 @@
 
 namespace Symfony\Component\Panther\ProcessManager;
 
+use Facebook\WebDriver\Firefox\FirefoxOptions;
 use Facebook\WebDriver\Remote\DesiredCapabilities;
 use Facebook\WebDriver\Remote\RemoteWebDriver;
 use Facebook\WebDriver\WebDriver;
@@ -63,6 +64,14 @@ public function start(): WebDriver
         $capabilities = DesiredCapabilities::firefox();
         $capabilities->setCapability('moz:firefoxOptions', $firefoxOptions);
 
+        // Prefer reduced motion, see https://developer.mozilla.org/fr/docs/Web/CSS/@media/prefers-reduced-motion
+        if ($_SERVER['PANTHER_REDUCED_MOTION'] ?? false) {
+            /** @var FirefoxOptions|array $firefoxOptions */
+            $firefoxOptions = $capabilities->getCapability('moz:firefoxOptions') ?? [];
+            $firefoxOptions = $firefoxOptions instanceof FirefoxOptions ? $firefoxOptions->toArray() : $firefoxOptions;
+            $firefoxOptions['prefs']['ui.prefersReducedMotion'] = 'reduced';
+        }
+
         foreach ($this->options['capabilities'] as $capability => $value) {
             $capabilities->setCapability($capability, $value);
         }