Add add-overrides.nix

reflex-dom-test-selenium/add-overrides.nix

@@ -0,0 +1,20 @@
+{ nixpkgs }: testPackage:
+  nixpkgs.haskell.lib.overrideCabal testPackage  
+    (drv: {
+
+      # The headless browser run as part of the tests will exit without this
+      preBuild = ''
+        export HOME="$PWD"
+      '';
+
+      testSystemDepends = with nixpkgs; (drv.testSystemDepends or []) ++ [
+        selenium-server-standalone which
+        chromium
+        nixpkgs.iproute
+      ];
+
+      # The headless browser run as part of gc tests would hang/crash without this
+      preCheck = ''
+        export FONTCONFIG_PATH=${nixpkgs.fontconfig.out}/etc/fonts
+      '';
+    })