♻️ Create backend package (#643)

packages/backend/next/trpc/client.ts

@@ -0,0 +1,52 @@
+import { MutationCache } from "@tanstack/react-query";
+import { httpBatchLink } from "@trpc/client";
+import { createTRPCNext } from "@trpc/next";
+import toast from "react-hot-toast";
+import superjson from "superjson";
+
+import { AppRouter } from "../../trpc/routers";
+
+export * from "../../trpc/types";
+
+export const trpc = createTRPCNext<AppRouter>({
+  unstable_overrides: {
+    useMutation: {
+      async onSuccess(opts) {
+        /**
+         * @note that order here matters:
+         * The order here allows route changes in `onSuccess` without
+         * having a flash of content change whilst redirecting.
+         **/
+        await opts.originalFn();
+        if (!opts.meta?.doNotInvalidate) {
+          await opts.queryClient.invalidateQueries();
+        }
+      },
+    },
+  },
+  config() {
+    return {
+      links: [
+        httpBatchLink({
+          url: `/api/trpc`,
+        }),
+      ],
+      transformer: superjson,
+      queryClientConfig: {
+        defaultOptions: {
+          queries: {
+            cacheTime: Infinity,
+          },
+        },
+        mutationCache: new MutationCache({
+          onError: () => {
+            toast.error(
+              "Uh oh! Something went wrong. The issue has been logged and we'll fix it as soon as possible. Please try again later.",
+            );
+          },
+        }),
+      },
+    };
+  },
+  ssr: false,
+});

packages/backend/next/trpc/server.ts

@@ -0,0 +1,12 @@
+import * as trpcNext from "@trpc/server/adapters/next";
+
+import { createContext } from "../../trpc/context";
+import { appRouter } from "../../trpc/routers";
+import { withSessionRoute } from "../session";
+
+export const trpcNextApiHandler = withSessionRoute(
+  trpcNext.createNextApiHandler({
+    router: appRouter,
+    createContext,
+  }),
+);