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x/workers_middleware/session.ts

Placeholder for Worker-based middleware solution
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// deno-lint-ignore-file no-explicit-anyimport type { StorageArea } from 'https://ghuc.cc/qwtel/kv-storage-interface/index.d.ts';import { UUID } from 'https://ghuc.cc/qwtel/uuid-class/index.ts';import { Base64Decoder, Base64Encoder } from 'https://ghuc.cc/qwtel/base64-encoding/index.ts';
import { createDraft, finishDraft, Draft, enableMapSet } from 'https://cdn.skypack.dev/immer@9.0.14?dts';import { Encoder as BinaryEncoder, Decoder as BinaryDecoder } from 'https://cdn.skypack.dev/msgpackr@1.5.5?dts';
import type { Context, UnsignedCookiesContext, SignedCookiesContext } from './index.ts';import type { Awaitable } from './utils/common-types.ts';import type { EncryptedCookiesContext } from './cookies.ts';
const shortenId = (x: Uint8Array) => new Base64Encoder({ url: true }).encode(x);const parseUUID = (x?: string | null) => x != null ? new UUID(new Base64Decoder().decode(x)) : null
enableMapSet();// enablePatches();
type Rec = Record<PropertyKey, any>;type CookieContext = Context & (EncryptedCookiesContext | SignedCookiesContext | UnsignedCookiesContext);
interface SessionContext<S extends Rec = Rec> { session: S }export interface CookieSessionContext<S extends Rec = Rec> extends SessionContext<S> { cookieSession: S}export interface StorageSessionContext<S extends Rec = Rec> extends SessionContext<S> { storageSession: S}
export interface CookieSessionOptions<S extends Rec = Rec> { /** The name of the session cookie. Defaults to `sid`. */ cookieName?: string,
/** Session expiration time in seconds. Defaults to five minutes. */ expirationTtl?: number,
/** TODO */ defaultSession?: S,}
export interface StorageSessionOptions<S extends Rec = Rec> extends CookieSessionOptions<S> { /** The storage area where to persist the session objects. */ storage: StorageArea,}
/** * Cookie session middleware for worker runtimes. * * Requires a cookie store, preferably encrypted or signed. * * Important: This will serialize the entire session data and store it in a cookie. It is sent with every request! * Only applicable for small session objects. Use `withStorageSession` for a traditional, KV store-backed session. */export function cookieSession<S extends Rec = Rec>( options: CookieSessionOptions<S> = {}): <X extends CookieContext>(ax: Awaitable<X>) => Promise<X & CookieSessionContext<S>> { return async ax => { const ctx = await ax; const { cookieStore, cookies } = ctx; const { defaultSession, cookieName = 'obj', expirationTtl = 5 * 60 } = options
const [session, orig] = getCookieSessionProxy<S>(cookies[cookieName], { cookieName, expirationTtl, defaultSession, });
const newContext = Object.assign(ctx, { session, cookieSession: session })
ctx.effects.push(response => { const next: S = finishDraft(session) if (next !== orig) { cookieStore.set({ name: cookieName, value: stringifySessionCookie(next), expires: new Date(Date.now() + expirationTtl * 1000), sameSite: 'lax', httpOnly: true, }); }
return response; })
return newContext; };}
/** * Session middleware for worker runtimes. * * Need to provide a `StorageArea` to persist the session between requests. * See `@worker-tools/kv-storage`. * */// FIXME: Will "block" until session object is retrieved from KV => provide "unyielding" version that returns a promise?export function storageSession<S extends Rec = Rec>( options: StorageSessionOptions<S>): <X extends CookieContext>(ax: Awaitable<X>) => Promise<X & StorageSessionContext<S>> { return async ax => { const ctx = await ax; const { cookies, cookieStore } = ctx; const { storage, defaultSession, cookieName = 'sid', expirationTtl = 5 * 60 } = options
const [id, session, orig] = await getStorageSessionProxy<S>(cookies[cookieName], { storage, cookieName, expirationTtl, defaultSession, });
const newContext = Object.assign(ctx, { session, storageSession: session })
ctx.waitUntil((async () => { await ctx.closed; const next: S = finishDraft(session) if (next !== orig) { await storage.set(id, next, { expirationTtl }); } })())
ctx.effects.push(response => { if (!cookies[cookieName]) { cookieStore.set({ name: cookieName, value: shortenId(id), expires: new Date(Date.now() + expirationTtl * 1000), sameSite: 'lax', httpOnly: true, }); }
return response; })
return newContext; }; }
const stringifySessionCookie = <T>(value: T) => new Base64Encoder({ url: true }).encode(new BinaryEncoder({ structuredClone: true }).encode(value));
const parseSessionCookie = <T>(value: string) => <T>new BinaryDecoder({ structuredClone: true }).decode(new Base64Decoder().decode(value));
function getCookieSessionProxy<S extends Rec = Rec>( cookieVal: string | null | undefined, { defaultSession }: CookieSessionOptions<S>,): [Draft<S>, S] { const obj = cookieVal ? parseSessionCookie<S>(cookieVal) : defaultSession ?? <S>{}; const draft = createDraft(obj) return [draft, obj]
}
async function getStorageSessionProxy<S extends Rec = Rec>( cookieVal: string | null | undefined, { defaultSession, storage }: StorageSessionOptions<S>,): Promise<[UUID, Draft<S>, S]> { const sessionId = parseUUID(cookieVal) ?? new UUID(); const obj = (await storage.get<S>(sessionId)) ?? defaultSession ?? <S>{}; const draft = createDraft(obj) return [sessionId, draft, obj];}