def test_run_linter(git_repo, monkeypatch, capsys, _descr, paths, location,
expect):
"""Linter gets correct paths on command line and outputs just changed lines
We use ``echo`` as our "linter". It just adds the paths of each file to lint as an
"error" on a line of ``test.py``. What this test does is the equivalent of e.g.::
- creating a ``test.py`` such that the first line is modified after the last commit
- creating and committing ``one.py`` and ``two.py``
- running::
$ darker -L 'echo test.py:1:' one.py two.py
test.py:1: git-repo-root/one.py git-repo-root/two.py
"""
src_paths = git_repo.add({"test.py": "1\n2\n"}, commit="Initial commit")
src_paths["test.py"].write_bytes(b"one\n2\n")
monkeypatch.chdir(git_repo.root)
cmdline = f"echo {location}"
linting.run_linter(cmdline, Path(git_repo.root), {Path(p)
for p in paths},
RevisionRange("HEAD"))
# We can now verify that the linter received the correct paths on its command line
# by checking standard output from the our `echo` "linter".
# The test cases also verify that only linter reports on modified lines are output.
result = capsys.readouterr().out.splitlines()
# Use evil `eval()` so we get Windows compatible expected paths:
assert result == [
eval(f'f"{line}"', {"git_repo": git_repo}) for line in expect
]
def test_run_linter_non_worktree():
"""``run_linter()`` doesn't support linting commits, only the worktree"""
with pytest.raises(NotImplementedError):
linting.run_linter(
"dummy-linter",
Path("/dummy"),
{Path("dummy.py")},
RevisionRange.parse("..HEAD"),
)
def test_run_linter_return_value(git_repo, location, expect):
"""``run_linter()`` returns the number of linter errors on modified lines"""
src_paths = git_repo.add({"test.py": "1\n2\n"}, commit="Initial commit")
src_paths["test.py"].write_bytes(b"one\n2\n")
cmdline = f"echo {location}"
result = linting.run_linter(cmdline, Path(git_repo.root),
{Path("test.py")}, RevisionRange("HEAD"))
assert result == expect
def format_edited_parts(
srcs: Iterable[Path],
revision: str,
enable_isort: bool,
linter_cmdlines: List[str],
black_args: BlackArgs,
) -> Generator[Tuple[Path, str, str, List[str]], None, None]:
"""Black (and optional isort) formatting for chunks with edits since the last commit
1. run isort on each edited file (optional)
2. diff the given revision and worktree (optionally with isort modifications) for
all file & dir paths on the command line
3. extract line numbers in each edited to-file for changed lines
4. run black on the contents of each edited to-file
5. get a diff between the edited to-file and the reformatted content
6. convert the diff into chunks, keeping original and reformatted content for each
chunk
7. choose reformatted content for each chunk if there were any changed lines inside
the chunk in the edited to-file, or choose the chunk's original contents if no
edits were done in that chunk
8. concatenate all chosen chunks
9. verify that the resulting reformatted source code parses to an identical AST as
the original edited to-file
10. write the reformatted source back to the original file
11. run linter subprocesses for all edited files (11.-14. optional)
12. diff the given revision and worktree (after isort and Black reformatting) for
each file reported by a linter
13. extract line numbers in each file reported by a linter for changed lines
14. print only linter error lines which fall on changed lines
:param srcs: Directories and files to re-format
:param revision: The Git revision against which to compare the working tree
:param enable_isort: ``True`` to also run ``isort`` first on each changed file
:param linter_cmdlines: The command line(s) for running linters on the changed
files.
:param black_args: Command-line arguments to send to ``black.FileMode``
:return: A generator which yields details about changes for each file which should
be reformatted, and skips unchanged files.
"""
git_root = get_common_root(srcs)
changed_files = git_get_modified_files(srcs, revision, git_root)
edited_linenums_differ = EditedLinenumsDiffer(git_root, revision)
for path_in_repo in sorted(changed_files):
src = git_root / path_in_repo
worktree_content = src.read_text()
# 1. run isort
if enable_isort:
edited_content = apply_isort(
worktree_content,
src,
black_args.get("config"),
black_args.get("line_length"),
)
else:
edited_content = worktree_content
edited_lines = edited_content.splitlines()
max_context_lines = len(edited_lines)
for context_lines in range(max_context_lines + 1):
# 2. diff the given revision and worktree for the file
# 3. extract line numbers in the edited to-file for changed lines
edited_linenums = edited_linenums_differ.revision_vs_lines(
path_in_repo, edited_lines, context_lines)
if (enable_isort and not edited_linenums
and edited_content == worktree_content):
logger.debug("No changes in %s after isort", src)
break
# 4. run black
formatted = run_black(src, edited_content, black_args)
logger.debug("Read %s lines from edited file %s",
len(edited_lines), src)
logger.debug("Black reformat resulted in %s lines", len(formatted))
# 5. get the diff between the edited and reformatted file
opcodes = diff_and_get_opcodes(edited_lines, formatted)
# 6. convert the diff into chunks
black_chunks = list(
opcodes_to_chunks(opcodes, edited_lines, formatted))
# 7. choose reformatted content
chosen_lines: List[str] = list(
choose_lines(black_chunks, edited_linenums))
# 8. concatenate chosen chunks
result_str = joinlines(chosen_lines)
# 9. verify
logger.debug(
"Verifying that the %s original edited lines and %s reformatted lines "
"parse into an identical abstract syntax tree",
len(edited_lines),
len(chosen_lines),
)
try:
verify_ast_unchanged(edited_content, result_str, black_chunks,
edited_linenums)
except NotEquivalentError:
# Diff produced misaligned chunks which couldn't be reconstructed into
# a partially re-formatted Python file which produces an identical AST.
# Try again with a larger `-U<context_lines>` option for `git diff`,
# or give up if `context_lines` is already very large.
if context_lines == max_context_lines:
raise
logger.debug(
"AST verification failed. "
"Trying again with %s lines of context for `git diff -U`",
context_lines + 1,
)
continue
else:
# 10. A re-formatted Python file which produces an identical AST was
# created successfully - write an updated file or print the diff
# if there were any changes to the original
if result_str != worktree_content:
# `result_str` is just `chosen_lines` concatenated with newlines.
# We need both forms when showing diffs or modifying files.
# Pass them both on to avoid back-and-forth conversion.
yield src, worktree_content, result_str, chosen_lines
break
# 11. run linter subprocesses for all edited files (11.-14. optional)
# 12. diff the given revision and worktree (after isort and Black reformatting) for
# each file reported by a linter
# 13. extract line numbers in each file reported by a linter for changed lines
# 14. print only linter error lines which fall on changed lines
for linter_cmdline in linter_cmdlines:
run_linter(linter_cmdline, git_root, changed_files, revision)