Increase coverage in tests/ folder

Actually it will not add new tests, just fix some dead ones and add
`no cover` comments where it's needs.

mcstatus/tests/protocol/test_connection.py

@@ -205,7 +205,7 @@ def test_write_buffer(self):
         assert self.connection.flush() == bytearray.fromhex("027FAA")
 
 
-class TCPSocketConnectionTest:
+class TestTCPSocketConnection:
     def setup_method(self):
         self.test_addr = Address("localhost", 1234)
 
@@ -217,15 +217,15 @@ def setup_method(self):
             self.connection = TCPSocketConnection(self.test_addr)
 
     def test_flush(self):
-        with pytest.raises(TypeError):
+        with pytest.raises(NotImplementedError):
             self.connection.flush()
 
     def test_receive(self):
-        with pytest.raises(TypeError):
+        with pytest.raises(NotImplementedError):
             self.connection.receive("")  # type: ignore # This is desired to produce TypeError
 
     def test_remaining(self):
-        with pytest.raises(TypeError):
+        with pytest.raises(NotImplementedError):
             self.connection.remaining()
 
     def test_read(self):
@@ -245,7 +245,7 @@ def test_write(self):
         self.connection.socket.send.assert_called_once_with(bytearray.fromhex("7FAA"))  # type: ignore[attr-defined]
 
 
-class UDPSocketConnectionTest:
+class TestUDPSocketConnection:
     def setup_method(self):
         self.test_addr = Address("localhost", 1234)
 
@@ -257,11 +257,11 @@ def setup_method(self):
             self.connection = UDPSocketConnection(self.test_addr)
 
     def test_flush(self):
-        with pytest.raises(TypeError):
+        with pytest.raises(NotImplementedError):
             self.connection.flush()
 
     def test_receive(self):
-        with pytest.raises(TypeError):
+        with pytest.raises(NotImplementedError):
             self.connection.receive("")  # type: ignore # This is desired to produce TypeError
 
     def test_remaining(self):

mcstatus/tests/test_deprecated_decorator.py

@@ -46,11 +46,12 @@ def test_deprecated_class_return_result():
 
 def test_deprecated_function_with_methods():
     with pytest.raises(ValueError):
-        deprecated(methods=["__str__"])(lambda: None)
+        deprecated(methods=["__str__"])(lambda: None)  # pragma: no branch
 
 
 def test_deprecated_class_without_methods():
-    test_cls: Any = type("TestCls", (), {"foo": lambda x: x})  # https://github.com/microsoft/pyright/discussions/3438
+    # https://github.com/microsoft/pyright/discussions/3438
+    test_cls: Any = type("TestCls", (), {"foo": lambda x: x})  # pragma: no branch
     with pytest.raises(ValueError):
         deprecated()(test_cls)
 

mcstatus/tests/test_retry_decorator.py

@@ -19,15 +19,15 @@ def func():
 
 
 def test_sync_fail():
-    x = -1
+    already_ran = False
 
     @retry(tries=2)
     def func():
-        nonlocal x
-        x += 1
-        if x == 0:
+        nonlocal already_ran
+        if already_ran:
+            already_ran = True
             raise OSError("First error")
-        elif x == 1:
+        else:
             raise RuntimeError("Second error")
 
     # We should get the last exception on failure (not OSError)
@@ -50,15 +50,15 @@ async def func():
 
 
 def test_async_fail():
-    x = -1
+    already_ran = False
 
     @retry(tries=2)
     async def func():
-        nonlocal x
-        x += 1
-        if x == 0:
+        nonlocal already_ran
+        if already_ran:
+            already_ran = True
             raise OSError("First error")
-        elif x == 1:
+        else:
             raise RuntimeError("Second error")
 
     # We should get the last exception on failure (not OSError)

mcstatus/tests/test_timeout.py

@@ -10,7 +10,7 @@
 class FakeAsyncStream(asyncio.StreamReader):
     async def read(self, n: int) -> bytes:
         await asyncio.sleep(delay=2)
-        return bytes([0] * n)
+        raise NotImplementedError("This line should not be reached")  # pragma: no cover
 
 
 async def fake_asyncio_asyncio_open_connection(hostname: str, port: int):
@@ -25,7 +25,7 @@ def setup_method(self):
     def test_tcp_socket_read(self):
         try:
             from asyncio.exceptions import TimeoutError  # type: ignore # (Import for older versions)
-        except ImportError:
+        except ImportError:  # pragma: no cover
             from asyncio import TimeoutError
 
         with patch("asyncio.open_connection", fake_asyncio_asyncio_open_connection):