Merge pull request #140 from ivanov/non-git-repos

Allow running on plain (non-git) directories

Author: akaihola

CHANGES.rst

@@ -46,6 +46,7 @@ Added
 - Darker now allows itself to modify files when called with ``pre-commit -o HEAD``, but
   also emits a warning about this being an experimental feature
 - Mention Black's possible new line range formatting support in README
+- Darker can now be used in a plain directory tree in addition to Git repositories
 
 Fixed
 -----

src/darker/__main__.py

@@ -27,7 +27,8 @@
     RevisionRange,
     get_missing_at_revision,
     git_get_content_at_revision,
-    git_get_modified_files,
+    git_get_modified_python_files,
+    git_is_repository,
 )
 from darker.help import ISORT_INSTRUCTION
 from darker.highlighting import colorize
@@ -369,10 +370,14 @@ def main(argv: List[str] = None) -> int:
         black_exclude = set()
     else:
         # In other modes, only process files which have been modified.
-        # These are relative to `root`:
-        changed_files_to_process = git_get_modified_files(
-            files_to_process, revrange, root
-        )
+        if git_is_repository(root):
+            changed_files_to_process = git_get_modified_python_files(
+                files_to_process, revrange, root
+            )
+        else:
+            changed_files_to_process = {
+                path.relative_to(root) for path in files_to_process
+            }
         black_exclude = {
             f for f in changed_files_to_process if root / f not in files_to_blacken
         }

src/darker/git.py

@@ -32,6 +32,21 @@
 PRE_COMMIT_FROM_TO_REFS = ":PRE-COMMIT:"
 
 
+def git_is_repository(path: Path) -> bool:
+    """Return ``True`` if ``path`` is inside a Git working tree"""
+    try:
+        lines = _git_check_output_lines(
+            ["rev-parse", "--is-inside-work-tree"], path, exit_on_error=False
+        )
+        return lines[:1] == ["true"]
+    except CalledProcessError as exc_info:
+        if exc_info.returncode != 128 or not exc_info.stderr.startswith(
+            "fatal: not a git repository"
+        ):
+            raise
+        return False
+
+
 def git_get_mtime_at_commit(path: Path, revision: str, cwd: Path) -> str:
     """Return the committer date of the given file at the given revision
 
@@ -267,10 +282,10 @@ def _git_ls_files_others(relative_paths: Set[Path], cwd: Path) -> Set[Path]:
     return {Path(line) for line in lines}
 
 
-def git_get_modified_files(
+def git_get_modified_python_files(
     paths: Iterable[Path], revrange: RevisionRange, cwd: Path
 ) -> Set[Path]:
-    """Ask Git for modified and untracked files
+    """Ask Git for modified and untracked ``*.py`` files
 
     - ``git diff --name-only --relative <rev> -- <path(s)>``
     - ``git ls-files --others --exclude-standard -- <path(s)>``

src/darker/tests/test_git.py

@@ -18,6 +18,25 @@
 from darker.utils import GIT_DATEFORMAT, TextDocument
 
 
+def test_tmp_path_sanity(tmp_path):
+    """Make sure Pytest temporary directories aren't inside a Git repository"""
+    try:
+        result = git._git_check_output_lines(
+            ["rev-parse", "--absolute-git-dir"], tmp_path, exit_on_error=False
+        )
+    except CalledProcessError as exc_info:
+        if exc_info.returncode != 128 or not exc_info.stderr.startswith(
+            "fatal: not a git repository"
+        ):
+            raise
+    else:
+        output = "\n".join(result)
+        raise AssertionError(
+            f"Temporary directory {tmp_path} for tests is not clean."
+            f" There is a Git directory in {output}"
+        )
+
+
 @pytest.mark.parametrize(
     "revision_range, expect",
     [
@@ -508,8 +527,8 @@ def test_git_ls_files_others(git_repo):
     modify_paths={},
     paths=[],
 )
-def test_git_get_modified_files(git_repo, modify_paths, paths, expect):
-    """Tests for `darker.git.git_get_modified_files()`"""
+def test_git_get_modified_python_files(git_repo, modify_paths, paths, expect):
+    """Tests for `darker.git.git_get_modified_python_files()`"""
     root = Path(git_repo.root)
     git_repo.add(
         {
@@ -530,7 +549,9 @@ def test_git_get_modified_files(git_repo, modify_paths, paths, expect):
             absolute_path.write_bytes(content.encode("ascii"))
     revrange = git.RevisionRange("HEAD", ":WORKTREE:")
 
-    result = git.git_get_modified_files({root / p for p in paths}, revrange, cwd=root)
+    result = git.git_get_modified_python_files(
+        {root / p for p in paths}, revrange, cwd=root
+    )
 
     assert result == {Path(p) for p in expect}
 
@@ -677,11 +698,11 @@ def branched_repo(tmp_path_factory):
         expect={"mod_both.py", "mod_same.py", "mod_branch.py"},
     ),
 )
-def test_git_get_modified_files_revision_range(
+def test_git_get_modified_python_files_revision_range(
     _description, branched_repo, revrange, expect
 ):
-    """Test for :func:`darker.git.git_get_modified_files` with a revision range"""
-    result = git.git_get_modified_files(
+    """Test for :func:`darker.git.git_get_modified_python_files` with revision range"""
+    result = git.git_get_modified_python_files(
         [Path(branched_repo.root)],
         git.RevisionRange.parse_with_common_ancestor(revrange, branched_repo.root),
         Path(branched_repo.root),

src/darker/tests/test_main.py

@@ -8,13 +8,14 @@
 from pathlib import Path
 from textwrap import dedent
 from types import SimpleNamespace
-from unittest.mock import patch
+from unittest.mock import call, patch
 
 import pytest
 from black import find_project_root
 
 import darker.__main__
 import darker.import_sorting
+import darker.linting
 from darker.exceptions import MissingPackageError
 from darker.git import WORKTREE, RevisionRange
 from darker.tests.helpers import isort_present
@@ -562,6 +563,57 @@ def test_main(
     assert retval == expect_retval
 
 
+def test_main_in_plain_directory(tmp_path, capsys):
+    """Darker works also in a plain directory tree"""
+    subdir_a = tmp_path / "subdir_a"
+    subdir_c = tmp_path / "subdir_b/subdir_c"
+    subdir_a.mkdir()
+    subdir_c.mkdir(parents=True)
+    (subdir_a / "non-python file.txt").write_text("not  reformatted\n")
+    (subdir_a / "python file.py").write_text("import  sys, os\nprint('ok')")
+    (subdir_c / "another python file.py").write_text("a  =5")
+    with patch.object(darker.linting, "run_linter") as run_linter:
+
+        retval = darker.__main__.main(
+            ["--diff", "--check", "--isort", "--lint", "my-linter", str(tmp_path)]
+        )
+
+    assert retval == 1
+    assert run_linter.call_args_list == [
+        call(
+            "my-linter",
+            tmp_path,
+            {
+                Path("subdir_a/python file.py"),
+                Path("subdir_b/subdir_c/another python file.py"),
+            },
+            RevisionRange(rev1="HEAD", rev2=":WORKTREE:"),
+        )
+    ]
+    output = capsys.readouterr().out
+    output = re.sub(
+        r"\d{4}-\d\d-\d\d \d\d:\d\d:\d\d\.\d\d\d\d\d\d", "<timestamp>", output
+    )
+    assert output == dedent(
+        """\
+        --- subdir_a/python file.py	<timestamp> +0000
+        +++ subdir_a/python file.py	<timestamp> +0000
+        @@ -1,2 +1,4 @@
+        -import  sys, os
+        -print('ok')
+        +import os
+        +import sys
+        +
+        +print("ok")
+        --- subdir_b/subdir_c/another python file.py	<timestamp> +0000
+        +++ subdir_b/subdir_c/another python file.py	<timestamp> +0000
+        @@ -1 +1 @@
+        -a  =5
+        +a = 5
+        """
+    )
+
+
 @pytest.mark.parametrize(
     "encoding, text", [(b"utf-8", b"touch\xc3\xa9"), (b"iso-8859-1", b"touch\xe9")]
 )