update firefox preferences

packages/tailwindcss/playwright.config.ts

@@ -42,7 +42,31 @@ export default defineConfig({
     },
     {
       name: 'firefox',
-      use: { ...devices['Desktop Firefox'] },
+      use: {
+        ...devices['Desktop Firefox'],
+        // https://playwright.dev/docs/test-use-options#more-browser-and-context-options
+        launchOptions: {
+          // https://playwright.dev/docs/api/class-browsertype#browser-type-launch-option-firefox-user-prefs
+          firefoxUserPrefs: {
+            // By default, headless Firefox runs as though no pointers
+            // capabilities are available.
+            // https://github.com/microsoft/playwright/issues/7769#issuecomment-966098074
+            //
+            // This impacts our `hover` variant implementation which uses an
+            // '(hover: hover)' media query to determine if hover is available.
+            //
+            // Available values for pointer capabilities:
+            // NO_POINTER            = 0x00;
+            // COARSE_POINTER        = 0x01;
+            // FINE_POINTER          = 0x02;
+            // HOVER_CAPABLE_POINTER = 0x04;
+            //
+            // Setting to 0x02 | 0x04 says the system supports a mouse
+            'ui.primaryPointerCapabilities': 0x02 | 0x04,
+            'ui.allPointerCapabilities': 0x02 | 0x04,
+          },
+        },
+      },
     },
 
     /* Test against mobile viewports. */