Make Session more convenient to use

.gitignore

@@ -15,3 +15,5 @@ build/
 **/mtproto/abcs/
 **/mtproto/functions/
 **/mtproto/types/
+**/testbed.py
+*.session

client/src/telethon/_impl/client/client/auth.py

@@ -3,6 +3,7 @@ from __future__ import annotations
 from typing import TYPE_CHECKING, Optional, Union
 
 from ...mtproto.mtp.types import RpcError
+from ...session.message_box.defs import Session
 from ...session.message_box.defs import User as SessionUser
 from ...tl import abcs, functions, types
 from ..types.chat.user import User
@@ -141,3 +142,8 @@ async def check_password(
 
 async def sign_out(self: Client) -> None:
     await self(functions.auth.log_out())
+
+
+def session(self: Client) -> Session:
+    self._config.session.state = self._message_box.session_state()
+    return self._config.session

client/src/telethon/_impl/client/client/client.py

@@ -6,6 +6,7 @@ from typing import Deque, Optional, Self, Type, TypeVar, Union
 from ...mtsender.sender import Sender
 from ...session.chat.hash_cache import ChatHashCache
 from ...session.chat.packed import PackedChat
+from ...session.message_box.defs import Session
 from ...session.message_box.messagebox import MessageBox
 from ...tl import abcs
 from ...tl.core.request import Request
@@ -20,6 +21,7 @@ from .auth import (
     check_password,
     is_authorized,
     request_login_code,
+    session,
     sign_in,
     sign_out,
 )
@@ -126,6 +128,15 @@ class Client:
     async def sign_out(self) -> None:
         await sign_out(self)
 
+    @property
+    def session(self) -> Session:
+        """
+        Up-to-date session state, useful for persisting it to storage.
+
+        Mutating the returned object may cause the library to misbehave.
+        """
+        return session(self)
+
     async def inline_query(
         self, bot: ChatLike, query: str, *, chat: Optional[ChatLike] = None
     ) -> None:

client/src/telethon/_impl/session/message_box/defs.py

@@ -1,6 +1,7 @@
+import base64
 import logging
 from enum import Enum
-from typing import List, Literal, Optional, Union
+from typing import Any, Dict, List, Literal, Optional, Self, Union
 
 from ...tl import abcs
 
@@ -62,14 +63,81 @@ class Session:
     def __init__(
         self,
         *,
-        dcs: List[DataCenter],
-        user: Optional[User],
-        state: Optional[UpdateState],
+        dcs: Optional[List[DataCenter]] = None,
+        user: Optional[User] = None,
+        state: Optional[UpdateState] = None,
     ):
-        self.dcs = dcs
+        self.dcs = dcs or []
         self.user = user
         self.state = state
 
+    def to_dict(self) -> Dict[str, Any]:
+        return {
+            "dcs": [
+                {
+                    "id": dc.id,
+                    "addr": dc.addr,
+                    "auth": base64.b64encode(dc.auth).decode("ascii")
+                    if dc.auth
+                    else None,
+                }
+                for dc in self.dcs
+            ],
+            "user": {
+                "id": self.user.id,
+                "dc": self.user.dc,
+                "bot": self.user.bot,
+            }
+            if self.user
+            else None,
+            "state": {
+                "pts": self.state.pts,
+                "qts": self.state.qts,
+                "date": self.state.date,
+                "seq": self.state.seq,
+                "channels": [
+                    {"id": channel.id, "pts": channel.pts}
+                    for channel in self.state.channels
+                ],
+            }
+            if self.state
+            else None,
+        }
+
+    @classmethod
+    def from_dict(cls, dict: Dict[str, Any]) -> Self:
+        return cls(
+            dcs=[
+                DataCenter(
+                    id=dc["id"],
+                    addr=dc["addr"],
+                    auth=base64.b64decode(dc["auth"])
+                    if dc["auth"] is not None
+                    else None,
+                )
+                for dc in dict["dcs"]
+            ],
+            user=User(
+                id=dict["user"]["id"],
+                dc=dict["user"]["dc"],
+                bot=dict["user"]["bot"],
+            )
+            if dict["user"]
+            else None,
+            state=UpdateState(
+                pts=dict["state"]["pts"],
+                qts=dict["state"]["qts"],
+                date=dict["state"]["date"],
+                seq=dict["state"]["seq"],
+                channels=[
+                    ChannelState(id=channel["id"], pts=channel["pts"])
+                    for channel in dict["state"]["channels"]
+                ],
+            )
+            if dict["state"]
+            else None,
+        )
+
 
 class PtsInfo:
     __slots__ = ("pts", "pts_count", "entry")

client/tests/client_test.py

@@ -17,11 +17,7 @@ async def test_ping_pong() -> None:
     assert api_hash
     client = Client(
         Config(
-            session=Session(
-                dcs=[],
-                user=None,
-                state=None,
-            ),
+            session=Session(),
             api_id=int(api_id),
             api_hash=api_hash,
         )