[WIP] Handling Encoding Error.

isort/api.py

@@ -13,6 +13,7 @@
     FileSkipComment,
     FileSkipSetting,
     IntroducedSyntaxErrors,
+    UnsupportedEncodingError,
 )
 from .format import ask_whether_to_apply_changes_to_file, create_terminal_printer, show_unified_diff
 from .io import Empty
@@ -260,16 +261,20 @@ def check_file(
     - **extension**: The file extension that contains imports. Defaults to filename extension or py.
     - ****config_kwargs**: Any config modifications.
     """
-    with io.File.read(filename) as source_file:
-        return check_stream(
-            source_file.stream,
-            show_diff=show_diff,
-            extension=extension,
-            config=config,
-            file_path=file_path or source_file.path,
-            disregard_skip=disregard_skip,
-            **config_kwargs,
-        )
+    try:
+        with io.File.read(filename) as source_file:
+            return check_stream(
+                source_file.stream,
+                show_diff=show_diff,
+                extension=extension,
+                config=config,
+                file_path=file_path or source_file.path,
+                disregard_skip=disregard_skip,
+                **config_kwargs,
+            )
+
+    except UnsupportedEncodingError:
+        raise UnsupportedEncodingError(filename)
 
 
 def sort_file(
@@ -297,70 +302,76 @@ def sort_file(
     - **write_to_stdout**: If `True`, write to stdout instead of the input file.
     - ****config_kwargs**: Any config modifications.
     """
-    with io.File.read(filename) as source_file:
-        actual_file_path = file_path or source_file.path
-        config = _config(path=actual_file_path, config=config, **config_kwargs)
-        changed: bool = False
-        try:
-            if write_to_stdout:
-                changed = sort_stream(
-                    input_stream=source_file.stream,
-                    output_stream=sys.stdout,
-                    config=config,
-                    file_path=actual_file_path,
-                    disregard_skip=disregard_skip,
-                    extension=extension,
-                )
-            else:
-                tmp_file = source_file.path.with_suffix(source_file.path.suffix + ".isorted")
-                try:
-                    with tmp_file.open(
-                        "w", encoding=source_file.encoding, newline=""
-                    ) as output_stream:
-                        shutil.copymode(filename, tmp_file)
-                        changed = sort_stream(
-                            input_stream=source_file.stream,
-                            output_stream=output_stream,
-                            config=config,
-                            file_path=actual_file_path,
-                            disregard_skip=disregard_skip,
-                            extension=extension,
-                        )
-                    if changed:
-                        if show_diff or ask_to_apply:
-                            source_file.stream.seek(0)
-                            with tmp_file.open(
-                                encoding=source_file.encoding, newline=""
-                            ) as tmp_out:
-                                show_unified_diff(
-                                    file_input=source_file.stream.read(),
-                                    file_output=tmp_out.read(),
-                                    file_path=actual_file_path,
-                                    output=None if show_diff is True else cast(TextIO, show_diff),
-                                    color_output=config.color_output,
-                                )
-                                if show_diff or (
-                                    ask_to_apply
-                                    and not ask_whether_to_apply_changes_to_file(
-                                        str(source_file.path)
+    try:
+        with io.File.read(filename) as source_file:
+            actual_file_path = file_path or source_file.path
+            config = _config(path=actual_file_path, config=config, **config_kwargs)
+            changed: bool = False
+            try:
+                if write_to_stdout:
+                    changed = sort_stream(
+                        input_stream=source_file.stream,
+                        output_stream=sys.stdout,
+                        config=config,
+                        file_path=actual_file_path,
+                        disregard_skip=disregard_skip,
+                        extension=extension,
+                    )
+                else:
+                    tmp_file = source_file.path.with_suffix(source_file.path.suffix + ".isorted")
+                    try:
+                        with tmp_file.open(
+                            "w", encoding=source_file.encoding, newline=""
+                        ) as output_stream:
+                            shutil.copymode(filename, tmp_file)
+                            changed = sort_stream(
+                                input_stream=source_file.stream,
+                                output_stream=output_stream,
+                                config=config,
+                                file_path=actual_file_path,
+                                disregard_skip=disregard_skip,
+                                extension=extension,
+                            )
+                        if changed:
+                            if show_diff or ask_to_apply:
+                                source_file.stream.seek(0)
+                                with tmp_file.open(
+                                    encoding=source_file.encoding, newline=""
+                                ) as tmp_out:
+                                    show_unified_diff(
+                                        file_input=source_file.stream.read(),
+                                        file_output=tmp_out.read(),
+                                        file_path=actual_file_path,
+                                        output=None
+                                        if show_diff is True
+                                        else cast(TextIO, show_diff),
+                                        color_output=config.color_output,
                                     )
-                                ):
-                                    return False
-                        source_file.stream.close()
-                        tmp_file.replace(source_file.path)
-                        if not config.quiet:
-                            print(f"Fixing {source_file.path}")
-                finally:
-                    try:  # Python 3.8+: use `missing_ok=True` instead of try except.
-                        tmp_file.unlink()
-                    except FileNotFoundError:
-                        pass
-        except ExistingSyntaxErrors:
-            warn(f"{actual_file_path} unable to sort due to existing syntax errors")
-        except IntroducedSyntaxErrors:  # pragma: no cover
-            warn(f"{actual_file_path} unable to sort as isort introduces new syntax errors")
-
-        return changed
+                                    if show_diff or (
+                                        ask_to_apply
+                                        and not ask_whether_to_apply_changes_to_file(
+                                            str(source_file.path)
+                                        )
+                                    ):
+                                        return False
+                            source_file.stream.close()
+                            tmp_file.replace(source_file.path)
+                            if not config.quiet:
+                                print(f"Fixing {source_file.path}")
+                    finally:
+                        try:  # Python 3.8+: use `missing_ok=True` instead of try except.
+                            tmp_file.unlink()
+                        except FileNotFoundError:
+                            pass
+            except ExistingSyntaxErrors:
+                warn(f"{actual_file_path} unable to sort due to existing syntax errors")
+            except IntroducedSyntaxErrors:  # pragma: no cover
+                warn(f"{actual_file_path} unable to sort as isort introduces new syntax errors")
+
+            return changed
+
+    except UnsupportedEncodingError:
+        raise UnsupportedEncodingError(filename)
 
 
 def _config(

isort/exceptions.py

@@ -1,5 +1,6 @@
 """All isort specific exception classes should be defined here"""
-from typing import Any, Dict
+from pathlib import Path
+from typing import Any, Dict, Union
 
 from .profiles import profiles
 
@@ -157,3 +158,13 @@ def __init__(self, unsupported_settings: Dict[str, Dict[str, str]]):
             "https://pycqa.github.io/isort/docs/configuration/options/.\n"
         )
         self.unsupported_settings = unsupported_settings
+
+
+class UnsupportedEncodingError(ISortError):
+    """Raised when isort has introduced an encoding error while reading a file"""
+
+    def __init__(
+        self,
+        filename: Union[str, Path],
+    ):
+        super().__init__(f"Unknown encoding in {filename}")

isort/io.py

@@ -6,6 +6,8 @@
 from pathlib import Path
 from typing import Iterator, NamedTuple, TextIO, Union
 
+from .exceptions import UnsupportedEncodingError
+
 _ENCODING_PATTERN = re.compile(br"^[ \t\f]*#.*?coding[:=][ \t]*([-_.a-zA-Z0-9]+)")
 
 
@@ -37,7 +39,7 @@ def _open(filename):
             return text
         except Exception:
             buffer.close()
-            raise
+            raise UnsupportedEncodingError(filename)
 
     @staticmethod
     @contextmanager

isort/main.py

@@ -10,7 +10,7 @@
 from warnings import warn
 
 from . import __version__, api, sections
-from .exceptions import FileSkipped
+from .exceptions import FileSkipped, UnsupportedEncodingError
 from .format import create_terminal_printer
 from .logo import ASCII_ART
 from .profiles import profiles
@@ -67,9 +67,12 @@
 
 
 class SortAttempt:
-    def __init__(self, incorrectly_sorted: bool, skipped: bool) -> None:
+    def __init__(
+        self, incorrectly_sorted: bool, skipped: bool, supported_encoding: bool = True
+    ) -> None:
         self.incorrectly_sorted = incorrectly_sorted
         self.skipped = skipped
+        self.supported_encoding = supported_encoding
 
 
 def sort_imports(
@@ -101,6 +104,11 @@ def sort_imports(
             except FileSkipped:
                 skipped = True
             return SortAttempt(incorrectly_sorted, skipped)
+
+    except UnsupportedEncodingError:
+        if config.verbose:
+            warn(f"Encoding not supported for {file_name}")
+        return SortAttempt(incorrectly_sorted, skipped, False)
     except (OSError, ValueError) as error:
         warn(f"Unable to parse file {file_name} due to {error}")
         return None
@@ -842,6 +850,7 @@ def main(argv: Optional[Sequence[str]] = None, stdin: Optional[TextIOWrapper] =
     remapped_deprecated_args = config_dict.pop("remapped_deprecated_args", False)
     wrong_sorted_files = False
     all_attempt_broken = False
+    no_valid_encodings = False
 
     if "src_paths" in config_dict:
         config_dict["src_paths"] = {
@@ -917,9 +926,18 @@ def main(argv: Optional[Sequence[str]] = None, stdin: Optional[TextIOWrapper] =
 
         # If any files passed in are missing considered as error, should be removed
         is_no_attempt = True
+        unsupported_encodings = 0
+        total_files_scanned = 0
         for sort_attempt in attempt_iterator:
             if not sort_attempt:
                 continue  # pragma: no cover - shouldn't happen, satisfies type constraint
+
+            total_files_scanned += 1
+
+            if not sort_attempt.supported_encoding:
+                unsupported_encodings += 1
+                continue
+
             incorrectly_sorted = sort_attempt.incorrectly_sorted
             if arguments.get("check", False) and incorrectly_sorted:
                 wrong_sorted_files = True
@@ -929,6 +947,9 @@ def main(argv: Optional[Sequence[str]] = None, stdin: Optional[TextIOWrapper] =
                 )
             is_no_attempt = False
 
+        if total_files_scanned and unsupported_encodings == total_files_scanned:
+            no_valid_encodings = True
+
         num_skipped += len(skipped)
         if num_skipped and not arguments.get("quiet", False):
             if config.verbose:
@@ -971,6 +992,11 @@ def main(argv: Optional[Sequence[str]] = None, stdin: Optional[TextIOWrapper] =
     if all_attempt_broken:
         sys.exit(1)
 
+    if no_valid_encodings:
+        printer = create_terminal_printer(color=config.color_output)
+        printer.error("No valid encodings.")
+        sys.exit(1)
+
 
 if __name__ == "__main__":
     main()

tests/unit/test_main.py

@@ -316,6 +316,34 @@ def test_main(capsys, tmpdir):
         main.main(["-sp", str(config_file), "-"], stdin=input_content)
 
 
+def test_unsupported_encodings(tmpdir, capsys):
+    tmp_file = tmpdir.join("file.py")
+    tmp_file.write(
+        "# [syntax-error]\n"
+        "# -*- coding: IBO-8859-1 -*-\n"
+        '""" check correct unknown encoding declaration\n'
+        '"""\n'
+        "\n"
+        "__revision__ = 'יייי'\n"
+    )
+
+    # should throw an error if only unsupported encoding provided
+    with pytest.raises(SystemExit):
+        main.main([str(tmp_file)])
+    out, error = capsys.readouterr()
+
+    assert "No valid encodings." in error
+
+    # should not throw an error if at least one valid encoding found
+    normal_file = tmpdir.join("file1.py")
+    normal_file.write("import os\nimport sys")
+
+    main.main([str(tmp_file), str(normal_file)])
+    out, error = capsys.readouterr()
+
+    assert not error
+
+
 def test_isort_command():
     """Ensure ISortCommand got registered, otherwise setuptools error must have occurred"""
     assert main.ISortCommand