Enable cache when running with --diff (#1145) (#5499)
Co-authored-by: cobalt <61329810+cobaltt7@users.noreply.github.com>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
diff --git a/CHANGES.md b/CHANGES.md
index c5e4152..7e79d70 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -24,6 +24,9 @@
<!-- Changes to how Black can be configured -->
+- Enable the cache when using `--diff` to skip unmodified files and record unmodified
+ files as well-formatted (#5499)
+
### Packaging
<!-- Changes to how Black is packaged, such as dependency requirements -->
diff --git a/docs/usage_and_configuration/file_collection_and_discovery.md b/docs/usage_and_configuration/file_collection_and_discovery.md
index 330e1fe..a5e8b41 100644
--- a/docs/usage_and_configuration/file_collection_and_discovery.md
+++ b/docs/usage_and_configuration/file_collection_and_discovery.md
@@ -7,8 +7,8 @@
## Ignoring unmodified files
-_Black_ remembers files it has already formatted, unless the `--diff` flag is used or
-code is passed via standard input. This information is stored per-user. The exact
+_Black_ remembers files it has already formatted, unless code is passed via standard
+input or the `--no-cache` flag is used. This information is stored per-user. The exact
location of the file depends on the _Black_ version and the system on which _Black_ is
run. The file is non-portable. The standard location on common operating systems is:
diff --git a/src/black/__init__.py b/src/black/__init__.py
index 675ea87..847c4d2 100644
--- a/src/black/__init__.py
+++ b/src/black/__init__.py
@@ -1013,16 +1013,17 @@ def reformat_one(
cache = Cache.read(mode)
else:
cache = Cache.read(mode, cache_dir)
- if cache is not None and write_back not in (
- WriteBack.DIFF,
- WriteBack.COLOR_DIFF,
- ):
+ if cache is not None:
if not cache.is_changed(src):
changed = Changed.CACHED
if changed is not Changed.CACHED and format_file_in_place(
src, fast=fast, write_back=write_back, mode=mode, lines=lines
):
changed = Changed.YES
+ can_cache_unmodified = (
+ write_back in (WriteBack.CHECK, WriteBack.DIFF, WriteBack.COLOR_DIFF)
+ and changed is Changed.NO
+ )
# Formatting only some lines doesn't make the whole file formatted, and
# the cache key doesn't include the line ranges, so don't record it.
if (
@@ -1030,7 +1031,7 @@ def reformat_one(
and not lines
and (
(write_back is WriteBack.YES and changed is not Changed.CACHED)
- or (write_back is WriteBack.CHECK and changed is Changed.NO)
+ or can_cache_unmodified
)
):
cache.write([src])
diff --git a/src/black/concurrency.py b/src/black/concurrency.py
index 9953030..88bfda8 100644
--- a/src/black/concurrency.py
+++ b/src/black/concurrency.py
@@ -180,10 +180,7 @@ async def schedule_formatting(
cache = Cache.read(mode)
else:
cache = Cache.read(mode, cache_dir)
- if cache is not None and write_back not in (
- WriteBack.DIFF,
- WriteBack.COLOR_DIFF,
- ):
+ if cache is not None:
sources, cached = cache.filtered_cached(sources)
for src in sorted(cached):
report.done(src, Changed.CACHED)
@@ -237,11 +234,15 @@ async def schedule_formatting(
report.failed(src, exc)
else:
changed = Changed.YES if task.result() else Changed.NO
- # If the file was written back or was successfully checked as
- # well-formatted, store this information in the cache.
- if write_back is WriteBack.YES or (
- write_back is WriteBack.CHECK and changed is Changed.NO
- ):
+ can_cache_unmodified = (
+ write_back in (
+ WriteBack.CHECK,
+ WriteBack.DIFF,
+ WriteBack.COLOR_DIFF,
+ )
+ and changed is Changed.NO
+ )
+ if write_back is WriteBack.YES or can_cache_unmodified:
sources_to_cache.append(src)
report.done(src, changed)
if cancelled:
diff --git a/tests/test_black.py b/tests/test_black.py
index 439e6ea..b3b6f2f 100644
--- a/tests/test_black.py
+++ b/tests/test_black.py
@@ -2989,6 +2989,62 @@ def test_no_cache_when_writeback_diff(self, color: bool) -> None:
write_cache.assert_not_called()
@pytest.mark.parametrize("color", [False, True], ids=["no-color", "with-color"])
+ def test_cache_written_when_writeback_diff_and_unmodified(
+ self, color: bool
+ ) -> None:
+ mode = DEFAULT_MODE
+ with cache_dir() as workspace:
+ src = (workspace / "test.py").resolve()
+ src.write_text('print("hello")\n', encoding="utf-8")
+ cmd = [str(src), "--diff"]
+ if color:
+ cmd.append("--color")
+ invokeBlack(cmd)
+ cache = black.Cache.read(mode, workspace)
+ assert not cache.is_changed(src)
+
+ @pytest.mark.parametrize("color", [False, True], ids=["no-color", "with-color"])
+ def test_cache_used_when_writeback_diff_already_cached(self, color: bool) -> None:
+ mode = DEFAULT_MODE
+ with cache_dir() as workspace:
+ src = (workspace / "test.py").resolve()
+ src.write_text("print('hello')", encoding="utf-8")
+ cache = black.Cache.read(mode, workspace)
+ cache.write([src])
+ cmd = ["--config", str(THIS_DIR / "empty.toml"), str(src), "--diff"]
+ if color:
+ cmd.append("--color")
+ result = BlackRunner().invoke(black.main, cmd)
+ assert result.exit_code == 0
+ assert "1 file would be left unchanged" in result.output
+ assert "@@" not in result.output
+
+ @pytest.mark.parametrize("color", [False, True], ids=["no-color", "with-color"])
+ @event_loop()
+ def test_cache_multiple_files_when_writeback_diff(self, color: bool) -> None:
+ mode = DEFAULT_MODE
+ with (
+ cache_dir() as workspace,
+ patch("concurrent.futures.ProcessPoolExecutor", new=ThreadPoolExecutor),
+ ):
+ one = (workspace / "one.py").resolve()
+ one.write_text('print("hello")\n', encoding="utf-8")
+ two = (workspace / "two.py").resolve()
+ two.write_text("print('world')", encoding="utf-8")
+ cache = black.Cache.read(mode, workspace)
+ cache.write([one])
+ cmd = ["--config", str(THIS_DIR / "empty.toml"), "--diff", str(workspace)]
+ if color:
+ cmd.append("--color")
+ result = BlackRunner().invoke(black.main, cmd)
+ assert result.exit_code == 0
+ expected = "1 file would be reformatted, 1 file would be left unchanged."
+ assert expected in result.output
+ cache = black.Cache.read(mode, workspace)
+ assert not cache.is_changed(one)
+ assert cache.is_changed(two)
+
+ @pytest.mark.parametrize("color", [False, True], ids=["no-color", "with-color"])
@event_loop()
def test_output_locking_when_writeback_diff(self, color: bool) -> None:
with cache_dir() as workspace:
