feat: centralize application framework primitives

packages/core/src/storage.ts

@@ -17,6 +17,16 @@ export interface CookieStore {
   set(name: string, value: string, options?: CookieOptions): void;
   delete(name: string, options?: CookieOptions): void;
   headers(): string[];
+  transaction<T extends Record<string, unknown> = Record<string, unknown>>(
+    name: string,
+    options?: CookieOptions,
+  ): TransactionCookie<T>;
+}
+
+export interface TransactionCookie<T extends Record<string, unknown>> {
+  set(value: T): void;
+  consume(): T | undefined;
+  clear(): void;
 }
 
 export interface SessionStore {
@@ -259,7 +269,7 @@ export function createCookieStore(req: Request): CookieStore {
   const incoming = parseCookieHeader(req.headers.get("cookie") ?? "");
   const outgoing: string[] = [];
 
-  return {
+  const store: CookieStore = {
     get(name) {
       return incoming[name];
     },
@@ -287,7 +297,45 @@ export function createCookieStore(req: Request): CookieStore {
     headers() {
       return [...outgoing];
     },
+    transaction<T extends Record<string, unknown>>(name: string, options: CookieOptions = {}) {
+      const policy: CookieOptions = {
+        path: "/",
+        httpOnly: true,
+        sameSite: "Lax",
+        maxAge: 600,
+        secure: new URL(req.url).protocol === "https:",
+        ...options,
+      };
+      return {
+        set(value: T) {
+          const json = JSON.stringify(value);
+          const encoded = btoa(unescape(encodeURIComponent(json)))
+            .replace(/\+/g, "-")
+            .replace(/\//g, "_")
+            .replace(/=+$/, "");
+          store.set(name, encoded, policy);
+        },
+        consume(): T | undefined {
+          const encoded = store.get(name);
+          store.delete(name, policy);
+          if (!encoded) return undefined;
+          try {
+            const padded = encoded
+              .replace(/-/g, "+")
+              .replace(/_/g, "/")
+              .padEnd(Math.ceil(encoded.length / 4) * 4, "=");
+            return JSON.parse(decodeURIComponent(escape(atob(padded)))) as T;
+          } catch {
+            return undefined;
+          }
+        },
+        clear() {
+          store.delete(name, policy);
+        },
+      };
+    },
   };
+  return store;
 }
 
 export function createSessionStore(