Merge pull request #1680 from PyCQA/issue/1668

Issue/1668

CHANGELOG.md

@@ -9,7 +9,8 @@ Find out more about isort's release policy [here](https://pycqa.github.io/isort/
   - Implemented #1648: Export MyPY type hints.
   - Implemented #1641: Identified import statements now return runnable code.
   - Implemented #1661: Added "wemake" profile.
-  - implemented #1669: Parallel (`-j`) now defaults to number of CPU cores if no value is provided.
+  - Implemented #1669: Parallel (`-j`) now defaults to number of CPU cores if no value is provided.
+  - Implemented #1668: Added a safeguard against accidental usage against /.
 
 ### 5.7.0 December 30th 2020
   - Fixed #1612: In rare circumstances an extra comma is added after import and before comment.

isort/main.py

@@ -347,6 +347,12 @@ def _build_arg_parser() -> argparse.ArgumentParser:
         dest="filename",
         help="Provide the filename associated with a stream.",
     )
+    target_group.add_argument(
+        "--allow-root",
+        action="store_true",
+        default=False,
+        help="Tells isort not to treat / specially, allowing it to be ran against the root dir.",
+    )
 
     output_group.add_argument(
         "-a",
@@ -1000,6 +1006,7 @@ def main(argv: Optional[Sequence[str]] = None, stdin: Optional[TextIOWrapper] =
     remapped_deprecated_args = config_dict.pop("remapped_deprecated_args", False)
     stream_filename = config_dict.pop("filename", None)
     ext_format = config_dict.pop("ext_format", None)
+    allow_root = config_dict.pop("allow_root", None)
     wrong_sorted_files = False
     all_attempt_broken = False
     no_valid_encodings = False
@@ -1037,6 +1044,11 @@ def main(argv: Optional[Sequence[str]] = None, stdin: Optional[TextIOWrapper] =
                 file_path=file_path,
                 extension=ext_format,
             )
+    elif "/" in file_names and not allow_root:
+        printer = create_terminal_printer(color=config.color_output)
+        printer.error("it is dangerous to operate recursively on '/'")
+        printer.error("use --allow-root to override this failsafe")
+        sys.exit(1)
     else:
         if stream_filename:
             printer = create_terminal_printer(color=config.color_output)