fix: cors

api/echos.ts

@@ -1,6 +1,9 @@
 import type { VercelRequest, VercelResponse } from "@vercel/node";
 import { echos } from "../src/echos";
+import { cors } from "../src/middleware/cors";
 
-export default function (_request: VercelRequest, response: VercelResponse) {
-  response.json({ echos });
-}
+export default cors(
+  async (_request: VercelRequest, response: VercelResponse) => {
+    response.json({ echos });
+  }
+);

src/middleware/cors.ts

@@ -0,0 +1,31 @@
+import type {
+  VercelRequest,
+  VercelResponse,
+  VercelApiHandler,
+} from "@vercel/node";
+
+const cors =
+  (fn: VercelApiHandler) => async (req: VercelRequest, res: VercelResponse) => {
+    res.setHeader("Access-Control-Allow-Credentials", "true");
+
+    res.setHeader("Access-Control-Allow-Origin", "*");
+
+    res.setHeader(
+      "Access-Control-Allow-Methods",
+      "GET,OPTIONS,PATCH,DELETE,POST,PUT"
+    );
+
+    res.setHeader(
+      "Access-Control-Allow-Headers",
+      "X-CSRF-Token, X-Requested-With, Accept, Accept-Version, Content-Length, Content-MD5, Content-Type, Date, X-Api-Version"
+    );
+
+    if (req.method === "OPTIONS") {
+      res.status(200).end();
+      return;
+    }
+
+    return await fn(req, res);
+  };
+
+export { cors };