Use aware datetimes to represent UTC

CHANGES.md

@@ -42,6 +42,8 @@
 
 <!-- Changes to Black's terminal output and error messages -->
 
+- Use aware UTC datetimes internally, avoids deprecation warning on Python 3.12 (#3728)
+
 ### _Blackd_
 
 <!-- Changes to blackd -->

docs/usage_and_configuration/the_basics.md

@@ -164,8 +164,8 @@ If you'd like colored diffs, you can enable them with `--color`.
 
 ```console
 $ black test.py --diff
---- test.py     2021-03-08 22:23:40.848954 +0000
-+++ test.py     2021-03-08 22:23:47.126319 +0000
+--- test.py     2021-03-08 22:23:40.848954+00:00
++++ test.py     2021-03-08 22:23:47.126319+00:00
 @@ -1 +1 @@
 -print ( 'hello, world' )
 +print("hello, world")

src/black/__init__.py

@@ -7,7 +7,7 @@
 import traceback
 from contextlib import contextmanager
 from dataclasses import replace
-from datetime import datetime
+from datetime import datetime, timezone
 from enum import Enum
 from json.decoder import JSONDecodeError
 from pathlib import Path
@@ -807,7 +807,7 @@ def format_file_in_place(
     elif src.suffix == ".ipynb":
         mode = replace(mode, is_ipynb=True)
 
-    then = datetime.utcfromtimestamp(src.stat().st_mtime)
+    then = datetime.fromtimestamp(src.stat().st_mtime, timezone.utc)
     header = b""
     with open(src, "rb") as buf:
         if mode.skip_source_first_line:
@@ -828,9 +828,9 @@ def format_file_in_place(
         with open(src, "w", encoding=encoding, newline=newline) as f:
             f.write(dst_contents)
     elif write_back in (WriteBack.DIFF, WriteBack.COLOR_DIFF):
-        now = datetime.utcnow()
-        src_name = f"{src}\t{then} +0000"
-        dst_name = f"{src}\t{now} +0000"
+        now = datetime.now(timezone.utc)
+        src_name = f"{src}\t{then}"
+        dst_name = f"{src}\t{now}"
         if mode.is_ipynb:
             diff_contents = ipynb_diff(src_contents, dst_contents, src_name, dst_name)
         else:
@@ -868,7 +868,7 @@ def format_stdin_to_stdout(
     write a diff to stdout. The `mode` argument is passed to
     :func:`format_file_contents`.
     """
-    then = datetime.utcnow()
+    then = datetime.now(timezone.utc)
 
     if content is None:
         src, encoding, newline = decode_bytes(sys.stdin.buffer.read())
@@ -893,9 +893,9 @@ def format_stdin_to_stdout(
                 dst += "\n"
             f.write(dst)
         elif write_back in (WriteBack.DIFF, WriteBack.COLOR_DIFF):
-            now = datetime.utcnow()
-            src_name = f"STDIN\t{then} +0000"
-            dst_name = f"STDOUT\t{now} +0000"
+            now = datetime.now(timezone.utc)
+            src_name = f"STDIN\t{then}"
+            dst_name = f"STDOUT\t{now}"
             d = diff(src, dst, src_name, dst_name)
             if write_back == WriteBack.COLOR_DIFF:
                 d = color_diff(d)

src/blackd/__init__.py

@@ -1,7 +1,7 @@
 import asyncio
 import logging
 from concurrent.futures import Executor, ProcessPoolExecutor
-from datetime import datetime
+from datetime import datetime, timezone
 from functools import partial
 from multiprocessing import freeze_support
 from typing import Set, Tuple
@@ -138,7 +138,7 @@ async def handle(request: web.Request, executor: Executor) -> web.Response:
         req_bytes = await request.content.read()
         charset = request.charset if request.charset is not None else "utf8"
         req_str = req_bytes.decode(charset)
-        then = datetime.utcnow()
+        then = datetime.now(timezone.utc)
 
         header = ""
         if skip_source_first_line:
@@ -165,9 +165,9 @@ async def handle(request: web.Request, executor: Executor) -> web.Response:
         # Only output the diff in the HTTP response
         only_diff = bool(request.headers.get(DIFF_HEADER, False))
         if only_diff:
-            now = datetime.utcnow()
-            src_name = f"In\t{then} +0000"
-            dst_name = f"Out\t{now} +0000"
+            now = datetime.now(timezone.utc)
+            src_name = f"In\t{then}"
+            dst_name = f"Out\t{now}"
             loop = asyncio.get_event_loop()
             formatted_str = await loop.run_in_executor(
                 executor,

tests/test_black.py

@@ -207,8 +207,8 @@ def test_piping(self) -> None:
 
     def test_piping_diff(self) -> None:
         diff_header = re.compile(
-            r"(STDIN|STDOUT)\t\d\d\d\d-\d\d-\d\d \d\d:\d\d:\d\d\.\d\d\d\d\d\d "
-            r"\+\d\d\d\d"
+            r"(STDIN|STDOUT)\t\d\d\d\d-\d\d-\d\d \d\d:\d\d:\d\d\.\d\d\d\d\d\d"
+            r"\+\d\d:\d\d"
         )
         source, _ = read_data("simple_cases", "expression.py")
         expected, _ = read_data("simple_cases", "expression.diff")
@@ -300,7 +300,7 @@ def test_expression_diff(self) -> None:
         tmp_file = Path(black.dump_to_file(source))
         diff_header = re.compile(
             rf"{re.escape(str(tmp_file))}\t\d\d\d\d-\d\d-\d\d "
-            r"\d\d:\d\d:\d\d\.\d\d\d\d\d\d \+\d\d\d\d"
+            r"\d\d:\d\d:\d\d\.\d\d\d\d\d\d\+\d\d:\d\d"
         )
         try:
             result = BlackRunner().invoke(
@@ -411,7 +411,7 @@ def test_skip_magic_trailing_comma(self) -> None:
         tmp_file = Path(black.dump_to_file(source))
         diff_header = re.compile(
             rf"{re.escape(str(tmp_file))}\t\d\d\d\d-\d\d-\d\d "
-            r"\d\d:\d\d:\d\d\.\d\d\d\d\d\d \+\d\d\d\d"
+            r"\d\d:\d\d:\d\d\.\d\d\d\d\d\d\+\d\d:\d\d"
         )
         try:
             result = BlackRunner().invoke(
@@ -1750,7 +1750,7 @@ def test_bpo_2142_workaround(self) -> None:
         tmp_file = Path(black.dump_to_file(source, ensure_final_newline=False))
         diff_header = re.compile(
             rf"{re.escape(str(tmp_file))}\t\d\d\d\d-\d\d-\d\d "
-            r"\d\d:\d\d:\d\d\.\d\d\d\d\d\d \+\d\d\d\d"
+            r"\d\d:\d\d:\d\d\.\d\d\d\d\d\d\+\d\d:\d\d"
         )
         try:
             result = BlackRunner().invoke(black.main, ["--diff", str(tmp_file)])

tests/test_blackd.py

@@ -114,7 +114,7 @@ async def test_blackd_pyi(self) -> None:
     @unittest_run_loop
     async def test_blackd_diff(self) -> None:
         diff_header = re.compile(
-            r"(In|Out)\t\d\d\d\d-\d\d-\d\d \d\d:\d\d:\d\d\.\d\d\d\d\d\d \+\d\d\d\d"
+            r"(In|Out)\t\d\d\d\d-\d\d-\d\d \d\d:\d\d:\d\d\.\d\d\d\d\d\d\+\d\d:\d\d"
         )
 
         source, _ = read_data("miscellaneous", "blackd_diff")