Add more testing stuff

vitest.browser.config.ts

@@ -0,0 +1,20 @@
+import { playwright } from "@vitest/browser-playwright";
+import solid from "vite-plugin-solid";
+import { defineConfig } from "vitest/config";
+
+export default defineConfig({
+	plugins: [solid()],
+	test: {
+		dir: "vitest-example",
+		browser: {
+			enabled: true,
+			provider: playwright({
+				contextOptions: {
+					colorScheme: "dark",
+				},
+			}),
+			// https://vitest.dev/config/browser/playwright
+			instances: [{ browser: "chromium" }],
+		},
+	},
+});