Hint at likely cause of ast parsing failure in error message (#2786)

[etc/vim.git] / src / black / files.py

diff --git a/src/black/files.py b/src/black/files.py
index ba60c84a27528ed378aa2f7073ebd7c4d830aef5..18c84237bf0ecee74221ca48c25bc62fb995c41b 100644 (file)
--- a/src/black/files.py
+++ b/src/black/files.py
@@ -17,7 +17,9 @@ from typing import (
     TYPE_CHECKING,
 )
 
+from mypy_extensions import mypyc_attr
 from pathspec import PathSpec
+from pathspec.patterns.gitwildmatch import GitWildMatchPatternError
 import tomli
 
 from black.output import err
@@ -29,7 +31,7 @@ if TYPE_CHECKING:
 
 
 @lru_cache()
-def find_project_root(srcs: Sequence[str]) -> Path:
+def find_project_root(srcs: Sequence[str]) -> Tuple[Path, str]:
     """Return a directory containing .git, .hg, or pyproject.toml.
 
     That directory will be a common parent of all files and directories
@@ -37,6 +39,10 @@ def find_project_root(srcs: Sequence[str]) -> Path:
 
     If no directory in the tree contains a marker that would specify it's the
     project root, the root of the file system is returned.
+
+    Returns a two-tuple with the first element as the project root path and
+    the second element as a string describing the method by which the
+    project root was discovered.
     """
     if not srcs:
         srcs = [str(Path.cwd().resolve())]
@@ -56,20 +62,20 @@ def find_project_root(srcs: Sequence[str]) -> Path:
 
     for directory in (common_base, *common_base.parents):
         if (directory / ".git").exists():
-            return directory
+            return directory, ".git directory"
 
         if (directory / ".hg").is_dir():
-            return directory
+            return directory, ".hg directory"
 
         if (directory / "pyproject.toml").is_file():
-            return directory
+            return directory, "pyproject.toml"
 
-    return directory
+    return directory, "file system root"
 
 
 def find_pyproject_toml(path_search_start: Tuple[str, ...]) -> Optional[str]:
     """Find the absolute filepath to a pyproject.toml if it exists"""
-    path_project_root = find_project_root(path_search_start)
+    path_project_root, _ = find_project_root(path_search_start)
     path_pyproject_toml = path_project_root / "pyproject.toml"
     if path_pyproject_toml.is_file():
         return str(path_pyproject_toml)
@@ -87,13 +93,14 @@ def find_pyproject_toml(path_search_start: Tuple[str, ...]) -> Optional[str]:
         return None
 
 
+@mypyc_attr(patchable=True)
 def parse_pyproject_toml(path_config: str) -> Dict[str, Any]:
     """Parse a pyproject toml file, pulling out relevant parts for Black
 
     If parsing fails, will raise a tomli.TOMLDecodeError
     """
-    with open(path_config, encoding="utf8") as f:
-        pyproject_toml = tomli.load(f)  # type: ignore  # due to deprecated API usage
+    with open(path_config, "rb") as f:
+        pyproject_toml = tomli.load(f)
     config = pyproject_toml.get("tool", {}).get("black", {})
     return {k.replace("--", "").replace("-", "_"): v for k, v in config.items()}
 
@@ -122,11 +129,17 @@ def get_gitignore(root: Path) -> PathSpec:
     if gitignore.is_file():
         with gitignore.open(encoding="utf-8") as gf:
             lines = gf.readlines()
-    return PathSpec.from_lines("gitwildmatch", lines)
+    try:
+        return PathSpec.from_lines("gitwildmatch", lines)
+    except GitWildMatchPatternError as e:
+        err(f"Could not parse {gitignore}: {e}")
+        raise
 
 
 def normalize_path_maybe_ignore(
-    path: Path, root: Path, report: Report
+    path: Path,
+    root: Path,
+    report: Optional[Report] = None,
 ) -> Optional[str]:
     """Normalize `path`. May return `None` if `path` was ignored.
 
@@ -136,12 +149,16 @@ def normalize_path_maybe_ignore(
         abspath = path if path.is_absolute() else Path.cwd() / path
         normalized_path = abspath.resolve().relative_to(root).as_posix()
     except OSError as e:
-        report.path_ignored(path, f"cannot be read because {e}")
+        if report:
+            report.path_ignored(path, f"cannot be read because {e}")
         return None
 
     except ValueError:
         if path.is_symlink():
-            report.path_ignored(path, f"is a symbolic link that points outside {root}")
+            if report:
+                report.path_ignored(
+                    path, f"is a symbolic link that points outside {root}"
+                )
             return None
 
         raise