Docs sample code leads to multiple type errors on `type: "multi"` sessions.

[adriangalilea]

Copy pasting the docs leads to the following code:

import { Bot, Context, session, SessionFlavor } from "https://deno.land/x/grammy@v1.35.0/mod.ts";
import { freeStorage } from "https://deno.land/x/grammy_storages@v2.5.1/free/src/mod.ts";

// Mock token for testing
const BOT_TOKEN = "example-token";

// Define the session interface matching the docs example
interface SessionData {
  foo?: string;
  bar: { prop: number };
  baz: { width?: number; height?: number };
}

// Create context type
type MyContext = Context & SessionFlavor<SessionData>;

// Create bot instance
const bot = new Bot<MyContext>(BOT_TOKEN);

// Set up multi-session exactly as in the docs
bot.use(
  session({
    type: "multi",
    foo: {
      // these are also the default values
      initial: () => undefined,
      getSessionKey: (ctx) => ctx.chat?.id.toString(),
      prefix: "",
    },
    bar: {
      initial: () => ({ prop: 0 }),
      storage: freeStorage(bot.token),
    },
    baz: {},
  }),
);

// Simple echo middleware
bot.on("message", async (ctx) => {
  console.log("Session data:", ctx.session);
  await ctx.reply("Hello!");
});

// Run the bot
bot.start();

Which gives you:

t bot = new Bot<MyContext>(token: BOT_TOKEN);
session
Type '{ readAllKeys(): Promise<{ prop: number; } | undefined>; read(key: string): Promise<{ prop: number; } | undefined>; write(key: string, data: { prop: number; } | undefined): Promise<...>; delete(key: string): Promise<...>; getToken(): Promise<...>; }' is not assignable to type 'StorageAdapter<{ prop: number; }>'.
  The types returned by 'readAllKeys()' are incompatible between these types.
    Type 'Promise<{ prop: number; } | undefined>' is not assignable to type 'Iterable<string> | AsyncIterable<string>'.deno-ts(2322)
session.ts(155, 5): The expected type comes from property 'storage' which is declared here on type 'SessionOptions<{ prop: number; }, Context & SessionFlavor<SessionData>>'

If I somehow fix the storage issue I also get

Type '"multi"' is not assignable to type '"single"'.deno-ts(2322)

But I'm not sure how to repro that error anymore as I'm trying a bunch of stuff.

[KnorpelSenf]

Gonna look into this, thanks for the detailed report