Merge pull request #68 from busybox11/fix-styled-components-nextjs

fix: Use NextJS recommended config for styled-components

src/app/layout.tsx

@@ -1,7 +1,8 @@
 import type { Metadata } from "next";
 import { Inter } from "next/font/google";
 import "./globals.css";
-import { ThemeProvider } from "@/components/theme-provider"
+import { ThemeProvider } from "@/components/theme-provider";
+import StyledComponentsRegistry from "@/lib/styled-components-registry";
 
 const inter = Inter({ subsets: ["latin"] });
 
@@ -25,7 +26,7 @@ export default function RootLayout({
           enableSystem
           disableTransitionOnChange
         >
-          {children}
+          <StyledComponentsRegistry>{children}</StyledComponentsRegistry>
         </ThemeProvider>
       </body>
     </html>

src/lib/styled-components-registry.tsx

@@ -0,0 +1,29 @@
+"use client";
+
+import React, { useState } from "react";
+import { useServerInsertedHTML } from "next/navigation";
+import { ServerStyleSheet, StyleSheetManager } from "styled-components";
+
+export default function StyledComponentsRegistry({
+  children,
+}: {
+  children: React.ReactNode;
+}) {
+  // Only create stylesheet once with lazy initial state
+  // x-ref: https://reactjs.org/docs/hooks-reference.html#lazy-initial-state
+  const [styledComponentsStyleSheet] = useState(() => new ServerStyleSheet());
+
+  useServerInsertedHTML(() => {
+    const styles = styledComponentsStyleSheet.getStyleElement();
+    styledComponentsStyleSheet.instance.clearTag();
+    return <>{styles}</>;
+  });
+
+  if (typeof window !== "undefined") return <>{children}</>;
+
+  return (
+    <StyleSheetManager sheet={styledComponentsStyleSheet.instance}>
+      {children}
+    </StyleSheetManager>
+  );
+}