Added create_channel_bot_link function

tests/test_utils/test_link.py

@@ -1,14 +1,22 @@
+from itertools import product
 from typing import Any, Dict
+from urllib.parse import parse_qs
 
 import pytest
 
-from aiogram.utils.link import BRANCH, create_telegram_link, create_tg_link, docs_url
+from aiogram.utils.link import (
+    BRANCH,
+    create_telegram_link,
+    create_tg_link,
+    docs_url,
+    create_channel_bot_link,
+)
 
 
 class TestLink:
     @pytest.mark.parametrize(
         "base,params,result",
-        [["user", dict(id=42), "tg://user?id=42"]],
+        [["user", {"id": 42}, "tg://user?id=42"]],
     )
     def test_create_tg_link(self, base: str, params: Dict[str, Any], result: str):
         assert create_tg_link(base, **params) == result
@@ -16,8 +24,8 @@ class TestLink:
     @pytest.mark.parametrize(
         "base,params,result",
         [
-            ["username", dict(), "https://t.me/username"],
-            ["username", dict(start="test"), "https://t.me/username?start=test"],
+            ["username", {}, "https://t.me/username"],
+            ["username", {"start": "test"}, "https://t.me/username?start=test"],
         ],
     )
     def test_create_telegram_link(self, base: str, params: Dict[str, Any], result: str):
@@ -31,3 +39,45 @@ class TestLink:
 
     def test_docs(self):
         assert docs_url("test.html") == f"https://docs.aiogram.dev/en/{BRANCH}/test.html"
+
+
+class TestCreateChannelBotLink:
+    def test_without_params(self):
+        assert create_channel_bot_link("test_bot") == "https://t.me/test_bot"
+
+    def test_parameter(self):
+        assert (
+            create_channel_bot_link("test_bot", parameter="parameter in group")
+            == "https://t.me/test_bot?startgroup=parameter+in+group"
+        )
+
+    def test_permissions(self):
+        # Is bad idea to put over 2k cases into parameterized test,
+        # so I've preferred to implement it inside the test
+
+        params = {
+            "change_info",
+            "post_messages",
+            "edit_messages",
+            "delete_messages",
+            "restrict_members",
+            "invite_users",
+            "pin_messages",
+            "promote_members",
+            "manage_video_chats",
+            "anonymous",
+            "manage_chat",
+        }
+
+        variants = product([True, False], repeat=len(params))
+        for index, variants in enumerate(variants):
+            kwargs = {k: v for k, v in zip(params, variants) if v}
+            if not kwargs:
+                # Variant without additional arguments is already covered
+                continue
+
+            link = create_channel_bot_link("test", **kwargs)
+            query = parse_qs(link.split("?", maxsplit=1)[-1], max_num_fields=1)
+            assert "admin" in query
+            admin = query["admin"][0]
+            assert set(admin.split("+")) == set(kwargs)