fetcher seralization

src/fetchers/body.ts

@@ -0,0 +1,24 @@
+import FormData = require('form-data');
+
+import { FetcherOptions } from '@/fetchers/types';
+
+export interface SeralizedBody {
+  headers: Record<string, string>;
+  body: FormData | URLSearchParams | string | undefined;
+}
+
+export function serializeBody(body: FetcherOptions['body']): SeralizedBody {
+  if (body === undefined || typeof body === 'string' || body instanceof URLSearchParams || body instanceof FormData)
+    return {
+      headers: {},
+      body,
+    };
+
+  // serialize as JSON
+  return {
+    headers: {
+      'Content-Type': 'application/json',
+    },
+    body: JSON.stringify(body),
+  };
+}