fix(deps): update nextjs monorepo to v15 (major) (#1844)

packages/api/src/shared.ts

@@ -0,0 +1,38 @@
+/**
+ * Creates a headers callback for a given source
+ * It will set the x-trpc-source header and cookies if needed
+ * @param source trpc source request comes from
+ * @returns headers callback
+ */
+export function createHeadersCallbackForSource(source: string) {
+  return async () => {
+    const headers = new Headers();
+    headers.set("x-trpc-source", source);
+
+    const cookies = await importCookiesAsync();
+    // We need to set cookie for ssr requests (for example with useSuspenseQuery or middleware)
+    if (cookies) {
+      headers.set("cookie", cookies);
+    }
+
+    return headers;
+  };
+}
+
+/**
+ * This is a workarround as cookies are not passed to the server
+ * when using useSuspenseQuery or middleware
+ * @returns cookie string on server or null on client
+ */
+async function importCookiesAsync() {
+  if (typeof window !== "undefined") {
+    return null;
+  }
+
+  const { cookies } = await import("next/headers");
+
+  return (await cookies())
+    .getAll()
+    .map(({ name, value }) => `${name}=${value}`)
+    .join(";");
+}