diff --git a/Makefile b/Makefile
index d400651..9f7d861 100644
--- a/Makefile
+++ b/Makefile
@@ -30,7 +30,7 @@ docs:
 
 install-deps:
 	@echo "> installing dependencies..."
-	pip install -r requirements-dev.txt
+	uv pip install -r requirements-dev.txt
 	pre-commit install
 
 tox:
diff --git a/rabbit/background_tasks.py b/rabbit/background_tasks.py
index 703051b..d5ffab5 100644
--- a/rabbit/background_tasks.py
+++ b/rabbit/background_tasks.py
@@ -37,6 +37,9 @@ def discard(self, task: asyncio.Task) -> None:
     def tasks_by_name(self) -> List[str]:
         return [task_name for task_name in self._tasks.keys()]
 
+    def __getitem__(self, name: str) -> asyncio.Task:
+        return self._tasks[name]
+
     def __iter__(self) -> Generator[asyncio.Task, None, None]:
         for _, task in self._tasks.items():
             yield task
diff --git a/rabbit/client.py b/rabbit/client.py
index e2f4a65..ec8e7e8 100644
--- a/rabbit/client.py
+++ b/rabbit/client.py
@@ -1,6 +1,6 @@
 import asyncio
 import random
-from typing import List, Optional
+from typing import List, Union
 from uuid import uuid4
 
 import aioamqp
@@ -40,7 +40,7 @@ def __repr__(self) -> str:
         return f"AioRabbitClient(connected={connected}, channels={channels}, max_channels={max_channels}, background_tasks={self._background_tasks})"
 
     @property
-    def server_properties(self) -> Optional[dict]:
+    def server_properties(self) -> Union[None, dict]:
         """Get server properties from the current connection."""
         try:
             return self.protocol.server_properties  # type: ignore
diff --git a/rabbit/subscribe.py b/rabbit/subscribe.py
index 3d6b5f4..1bc648d 100644
--- a/rabbit/subscribe.py
+++ b/rabbit/subscribe.py
@@ -1,7 +1,7 @@
 import asyncio
 import os
 from contextlib import suppress
-from typing import Callable, Optional
+from typing import Callable, Union
 
 from aioamqp.channel import Channel
 from aioamqp.envelope import Envelope
@@ -72,7 +72,6 @@ def __attrs_post_init__(self) -> None:
 
     @property
     def name(self) -> str:
-        """Object name."""
         return "Subscribe"
 
     @property
@@ -87,7 +86,7 @@ def channel(self, channel: Channel) -> None:
         self._dlx.channel = channel
         self._channel = channel
 
-    async def configure(self, channel: Optional[Channel] = None) -> None:
+    async def configure(self, channel: Union[None, Channel] = None) -> None:
         """Configure subscriber channel, queues and exchange."""
         await self.qos(prefetch_count=self.concurrent)
         with suppress(SynchronizationError):
diff --git a/tests/unit/test_background_tasks.py b/tests/unit/test_background_tasks.py
new file mode 100644
index 0000000..bd2d063
--- /dev/null
+++ b/tests/unit/test_background_tasks.py
@@ -0,0 +1,42 @@
+import asyncio
+
+import pytest
+
+from rabbit.background_tasks import BackgroundTasks
+from rabbit.job import async_echo_job
+
+
+@pytest.fixture
+def background_tasks():
+    return BackgroundTasks()
+
+
+async def test_background_tasks_add(background_tasks):
+    background_tasks.add("test-task", async_echo_job, b'{"message": "test"}')
+    assert len(background_tasks) == 1
+
+
+async def test_background_tasks_multiple_add(background_tasks):
+    background_tasks.add("test-task-1", async_echo_job, b'{"message": "test"}')
+    background_tasks.add("test-task-1", async_echo_job, b'{"message": "test"}')
+    background_tasks.add("test-task-2", async_echo_job, b'{"message": "test2"}')
+    assert len(background_tasks) == 2
+
+
+async def test_background_tasks_by_name(background_tasks):
+    background_tasks.add("test-task", async_echo_job, b'{"message": "test"}')
+    for task in background_tasks:
+        assert task.get_name() == "test-task"
+
+
+async def test_background_tasks_getitem(background_tasks):
+    background_tasks.add("test-task", async_echo_job, b'{"message": "test"}')
+    assert isinstance(background_tasks["test-task"], asyncio.Task)
+
+
+def test_background_tasks_len(background_tasks):
+    assert len(background_tasks) == 0
+
+
+def test_background_tasks_repr(background_tasks):
+    assert repr(background_tasks) == "BackgroundTasks(tasks=0, tasks_by_name=[])"
diff --git a/tests/unit/test_client.py b/tests/unit/test_client.py
index 7a23cdb..fa30e71 100644
--- a/tests/unit/test_client.py
+++ b/tests/unit/test_client.py
@@ -2,7 +2,7 @@
 
 import pytest
 
-from rabbit.client import aioamqp
+from rabbit.client import AioRabbitClient, aioamqp
 from rabbit.exceptions import AttributeNotInitialized
 from tests.conftest import AioAmqpMock
 
@@ -44,3 +44,8 @@ def test_server_properties_with_client_not_connected(client):
 
 def test_server_properties(client_mock):
     assert isinstance(client_mock.server_properties, dict)
+
+
+@pytest.mark.parametrize("attribute", ["transport", "server_properties", "protocol"])
+def test_client_attributes(attribute):
+    assert hasattr(AioRabbitClient, attribute)
diff --git a/tests/unit/test_dlx.py b/tests/unit/test_dlx.py
index d1fb0a9..2ee4542 100644
--- a/tests/unit/test_dlx.py
+++ b/tests/unit/test_dlx.py
@@ -1,5 +1,6 @@
 import pytest
 
+from rabbit.dlx import DLX
 from rabbit.exceptions import OperationError
 from tests.conftest import EnvelopeMock, PropertiesMock
 
@@ -20,3 +21,10 @@ async def test_send_event_error_without_client_connection(dlx):
 
 def test_dlx_repr(dlx):
     assert isinstance(repr(dlx), str)
+
+
+@pytest.mark.parametrize(
+    "attribute", ["exchange", "dlq_exchange", "queue", "delay_strategy", "channel"]
+)
+def test_dlx_attributes(attribute):
+    assert hasattr(DLX, attribute)
diff --git a/tests/unit/test_exceptions.py b/tests/unit/test_exceptions.py
new file mode 100644
index 0000000..990ffa2
--- /dev/null
+++ b/tests/unit/test_exceptions.py
@@ -0,0 +1,14 @@
+from rabbit.exceptions import ClientNotConnectedError, ExchangeNotFound
+
+
+def test_exchange_not_found_message():
+    assert (
+        str(ExchangeNotFound("test-exchange")) == "Exchange 'test-exchange' not found"
+    )
+
+
+def test_client_not_connected_error():
+    assert (
+        str(ClientNotConnectedError())
+        == "AioRabbitClient was not connected with RabbitMQ"
+    )
diff --git a/tests/unit/test_jobs.py b/tests/unit/test_jobs.py
index 186df2d..9ef8dd3 100644
--- a/tests/unit/test_jobs.py
+++ b/tests/unit/test_jobs.py
@@ -1,6 +1,14 @@
-from rabbit.job import async_echo_job
+import pytest
+
+from rabbit.job import async_chaos_job, async_echo_job
 
 
 async def test_async_echo_job():
     resp = await async_echo_job(b'{"process": 123}', skip_wait=True)
     assert resp == b'{"process": 123}'
+
+
+@pytest.mark.xfail(reason="The test may fail due to randomness issue")
+async def test_async_chaos_job():
+    resp = await async_chaos_job(b'{"process": 123}', skip_wait=True)
+    assert resp == b'{"process": 123}'
diff --git a/tests/unit/test_publish.py b/tests/unit/test_publish.py
index 7029862..d85845d 100644
--- a/tests/unit/test_publish.py
+++ b/tests/unit/test_publish.py
@@ -24,3 +24,10 @@ async def test_publish_confirms_disabled(publish):
 async def test_publish_confirms_enabled():
     publish = Publish(True)
     assert publish.publish_confirms is True
+
+
+@pytest.mark.parametrize(
+    "attribute", ["publish_confirms", "name", "channel_id", "channel"]
+)
+def test_publish_attributes(attribute):
+    assert hasattr(Publish, attribute)
diff --git a/tests/unit/test_queue.py b/tests/unit/test_queue.py
index 0159755..3d349be 100644
--- a/tests/unit/test_queue.py
+++ b/tests/unit/test_queue.py
@@ -1,7 +1,6 @@
-import attr
+import pytest
 
 
-def test_attributes(queue):
-    values = ["queue", True, {}]
-    for value in values:
-        assert value in attr.asdict(queue).values()
+@pytest.mark.parametrize("attribute", ["name", "durable", "arguments"])
+def test_attributes(queue, attribute):
+    assert hasattr(queue, attribute)
diff --git a/tests/unit/test_subscribe.py b/tests/unit/test_subscribe.py
index 4849c56..2fb6662 100644
--- a/tests/unit/test_subscribe.py
+++ b/tests/unit/test_subscribe.py
@@ -1,10 +1,9 @@
 import pytest
 
 from rabbit.exceptions import ClientNotConnectedError
+from rabbit.subscribe import Subscribe
 from tests.conftest import EnvelopeMock
 
-PAYLOAD = b'{"a": 1}'
-
 
 async def test_register_subscribe_without_client_connected(subscribe):
     with pytest.raises(ClientNotConnectedError):
@@ -25,3 +24,10 @@ def test_subscribe_repr(subscribe_mock):
 
 async def test_nack_event(subscribe_mock):
     await subscribe_mock.nack_event(EnvelopeMock())
+
+
+@pytest.mark.parametrize(
+    "attribute", ["task", "exchange", "queue", "concurrent", "delay_strategy"]
+)
+def test_subscribe_attributes(attribute):
+    assert hasattr(Subscribe, attribute)