Cors middleware

cors-middleware.ts

@@ -0,0 +1,33 @@
+import corsWrapper from 'cors';
+import { RequestHandler } from 'express';
+
+/**
+ * Hey there you curious :)
+ *
+ * By default, NextJS APIs are same-site origin only.
+ * But since *I needed the main project*
+ * to have public API access, I had to configure CORS.
+ *
+ * @see https://github.com/vercel/next.js/tree/canary/examples/api-routes-cors
+ * @see https://github.com/expressjs/cors#configuration-options
+ */
+const CORS_OPTIONS = {
+	methods: ['GET', 'OPTIONS'],
+};
+
+function promisifyMiddleware(middleware: RequestHandler) {
+	return (req: any, res: any) =>
+		new Promise((resolve, reject) => {
+			middleware(req, res, (result: Error | unknown) => {
+				if (result instanceof Error) {
+					return reject(result);
+				}
+				return resolve(result);
+			});
+		});
+}
+
+// Initialize the cors middleware
+const cors = promisifyMiddleware(corsWrapper(CORS_OPTIONS));
+
+export default cors;