X-Git-Url: https://git.madduck.net/etc/vim.git/blobdiff_plain/44d5da00b520a05cd56e58b3998660f64ea59ebd..42fdd1b91f87a92e39ad2676c863328dbf7d194d:/tests/test_blackd.py

diff --git a/tests/test_blackd.py b/tests/test_blackd.py
index 18b2c98..511bd86 100644
--- a/tests/test_blackd.py
+++ b/tests/test_blackd.py
@@ -1,5 +1,5 @@
 import re
-from typing import Any
+from typing import TYPE_CHECKING, Any, Callable, TypeVar
 from unittest.mock import patch
 
 import pytest
@@ -15,17 +15,23 @@ try:
 except ImportError as e:
     raise RuntimeError("Please install Black with the 'd' extra") from e
 
-try:
-    from aiohttp.test_utils import unittest_run_loop
-except ImportError:
-    # unittest_run_loop is unnecessary and a no-op since aiohttp 3.8, and aiohttp 4
-    # removed it. To maintain compatibility we can make our own no-op decorator.
-    def unittest_run_loop(func: Any, *args: Any, **kwargs: Any) -> Any:
-        return func
+if TYPE_CHECKING:
+    F = TypeVar("F", bound=Callable[..., Any])
+
+    unittest_run_loop: Callable[[F], F] = lambda x: x
+else:
+    try:
+        from aiohttp.test_utils import unittest_run_loop
+    except ImportError:
+        # unittest_run_loop is unnecessary and a no-op since aiohttp 3.8, and
+        # aiohttp 4 removed it. To maintain compatibility we can make our own
+        # no-op decorator.
+        def unittest_run_loop(func, *args, **kwargs):
+            return func
 
 
 @pytest.mark.blackd
-class BlackDTestCase(AioHTTPTestCase):
+class BlackDTestCase(AioHTTPTestCase):  # type: ignore[misc]
     def test_blackd_main(self) -> None:
         with patch("blackd.web.run_app"):
             result = CliRunner().invoke(blackd.main, [])
@@ -77,7 +83,9 @@ class BlackDTestCase(AioHTTPTestCase):
     async def test_blackd_invalid_python_variant(self) -> None:
         async def check(header_value: str, expected_status: int = 400) -> None:
             response = await self.client.post(
-                "/", data=b"what", headers={blackd.PYTHON_VARIANT_HEADER: header_value}
+                "/",
+                data=b"what",
+                headers={blackd.PYTHON_VARIANT_HEADER: header_value},
             )
             self.assertEqual(response.status, expected_status)
 
@@ -163,10 +171,19 @@ class BlackDTestCase(AioHTTPTestCase):
     @unittest_run_loop
     async def test_blackd_invalid_line_length(self) -> None:
         response = await self.client.post(
-            "/", data=b'print("hello")\n', headers={blackd.LINE_LENGTH_HEADER: "NaN"}
+            "/",
+            data=b'print("hello")\n',
+            headers={blackd.LINE_LENGTH_HEADER: "NaN"},
         )
         self.assertEqual(response.status, 400)
 
+    @unittest_run_loop
+    async def test_blackd_preview(self) -> None:
+        response = await self.client.post(
+            "/", data=b'print("hello")\n', headers={blackd.PREVIEW: "true"}
+        )
+        self.assertEqual(response.status, 204)
+
     @unittest_run_loop
     async def test_blackd_response_black_version_header(self) -> None:
         response = await self.client.post("/")