dulwich/dulwich/errors.py

# errors.py -- errors for dulwich
# Copyright (C) 2007 James Westby <jw+debian@jameswestby.net>
# Copyright (C) 2009-2012 Jelmer Vernooij <jelmer@jelmer.uk>
#
# SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
# Dulwich is dual-licensed under the Apache License, Version 2.0 and the GNU
# General Public License as published by the Free Software Foundation; version 2.0
# or (at your option) any later version. You can redistribute it and/or
# modify it under the terms of either of these two licenses.
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
# You should have received a copy of the licenses; if not, see
# <http://www.gnu.org/licenses/> for a copy of the GNU General Public License
# and <http://www.apache.org/licenses/LICENSE-2.0> for a copy of the Apache
# License, Version 2.0.
#

"""Dulwich-related exception classes and utility functions."""


# Please do not add more errors here, but instead add them close to the code
# that raises the error.

import binascii
from collections.abc import Sequence
from typing import Optional, Union


class ChecksumMismatch(Exception):
    """A checksum didn't match the expected contents."""

    def __init__(
        self,
        expected: Union[bytes, str],
        got: Union[bytes, str],
        extra: Optional[str] = None,
    ) -> None:
        """Initialize a ChecksumMismatch exception.

        Args:
            expected: The expected checksum value (bytes or hex string).
            got: The actual checksum value (bytes or hex string).
            extra: Optional additional error information.
        """
        if isinstance(expected, bytes) and len(expected) == 20:
            expected_str = binascii.hexlify(expected).decode("ascii")
        else:
            expected_str = (
                expected if isinstance(expected, str) else expected.decode("ascii")
            )
        if isinstance(got, bytes) and len(got) == 20:
            got_str = binascii.hexlify(got).decode("ascii")
        else:
            got_str = got if isinstance(got, str) else got.decode("ascii")
        self.expected = expected_str
        self.got = got_str
        self.extra = extra
        message = f"Checksum mismatch: Expected {expected_str}, got {got_str}"
        if self.extra is not None:
            message += f"; {extra}"
        Exception.__init__(self, message)


class WrongObjectException(Exception):
    """Baseclass for all the _ is not a _ exceptions on objects.

    Do not instantiate directly.

    Subclasses should define a type_name attribute that indicates what
    was expected if they were raised.
    """

    type_name: str

    def __init__(self, sha: bytes, *args: object, **kwargs: object) -> None:
        """Initialize a WrongObjectException.

        Args:
            sha: The SHA of the object that was not of the expected type.
            *args: Additional positional arguments.
            **kwargs: Additional keyword arguments.
        """
        Exception.__init__(self, f"{sha.decode('ascii')} is not a {self.type_name}")


class NotCommitError(WrongObjectException):
    """Indicates that the sha requested does not point to a commit."""

    type_name = "commit"


class NotTreeError(WrongObjectException):
    """Indicates that the sha requested does not point to a tree."""

    type_name = "tree"


class NotTagError(WrongObjectException):
    """Indicates that the sha requested does not point to a tag."""

    type_name = "tag"


class NotBlobError(WrongObjectException):
    """Indicates that the sha requested does not point to a blob."""

    type_name = "blob"


class MissingCommitError(Exception):
    """Indicates that a commit was not found in the repository."""

    def __init__(self, sha: bytes, *args: object, **kwargs: object) -> None:
        """Initialize a MissingCommitError.

        Args:
            sha: The SHA of the missing commit.
            *args: Additional positional arguments.
            **kwargs: Additional keyword arguments.
        """
        self.sha = sha
        Exception.__init__(self, f"{sha.decode('ascii')} is not in the revision store")


class ObjectMissing(Exception):
    """Indicates that a requested object is missing."""

    def __init__(self, sha: bytes, *args: object, **kwargs: object) -> None:
        """Initialize an ObjectMissing exception.

        Args:
            sha: The SHA of the missing object.
            *args: Additional positional arguments.
            **kwargs: Additional keyword arguments.
        """
        Exception.__init__(self, f"{sha.decode('ascii')} is not in the pack")


class ApplyDeltaError(Exception):
    """Indicates that applying a delta failed."""

    def __init__(self, *args: object, **kwargs: object) -> None:
        """Initialize an ApplyDeltaError.

        Args:
            *args: Error message and additional positional arguments.
            **kwargs: Additional keyword arguments.
        """
        Exception.__init__(self, *args, **kwargs)


class NotGitRepository(Exception):
    """Indicates that no Git repository was found."""

    def __init__(self, *args: object, **kwargs: object) -> None:
        """Initialize a NotGitRepository exception.

        Args:
            *args: Error message and additional positional arguments.
            **kwargs: Additional keyword arguments.
        """
        Exception.__init__(self, *args, **kwargs)


class GitProtocolError(Exception):
    """Git protocol exception."""

    def __init__(self, *args: object, **kwargs: object) -> None:
        """Initialize a GitProtocolError.

        Args:
            *args: Error message and additional positional arguments.
            **kwargs: Additional keyword arguments.
        """
        Exception.__init__(self, *args, **kwargs)

    def __eq__(self, other: object) -> bool:
        """Check equality between GitProtocolError instances.

        Args:
            other: The object to compare with.

        Returns:
            True if both are GitProtocolError instances with same args, False otherwise.
        """
        return isinstance(other, GitProtocolError) and self.args == other.args


class SendPackError(GitProtocolError):
    """An error occurred during send_pack."""


class HangupException(GitProtocolError):
    """Hangup exception."""

    def __init__(self, stderr_lines: Optional[Sequence[bytes]] = None) -> None:
        """Initialize a HangupException.

        Args:
            stderr_lines: Optional list of stderr output lines from the remote server.
        """
        if stderr_lines:
            super().__init__(
                "\n".join(
                    line.decode("utf-8", "surrogateescape") for line in stderr_lines
                )
            )
        else:
            super().__init__("The remote server unexpectedly closed the connection.")
        self.stderr_lines = stderr_lines

    def __eq__(self, other: object) -> bool:
        """Check equality between HangupException instances.

        Args:
            other: The object to compare with.

        Returns:
            True if both are HangupException instances with same stderr_lines, False otherwise.
        """
        return (
            isinstance(other, HangupException)
            and self.stderr_lines == other.stderr_lines
        )


class UnexpectedCommandError(GitProtocolError):
    """Unexpected command received in a proto line."""

    def __init__(self, command: Optional[str]) -> None:
        """Initialize an UnexpectedCommandError.

        Args:
            command: The unexpected command received, or None for flush-pkt.
        """
        command_str = "flush-pkt" if command is None else f"command {command}"
        super().__init__(f"Protocol got unexpected {command_str}")


class FileFormatException(Exception):
    """Base class for exceptions relating to reading git file formats."""


class PackedRefsException(FileFormatException):
    """Indicates an error parsing a packed-refs file."""


class ObjectFormatException(FileFormatException):
    """Indicates an error parsing an object."""


class NoIndexPresent(Exception):
    """No index is present."""


class CommitError(Exception):
    """An error occurred while performing a commit."""


class RefFormatError(Exception):
    """Indicates an invalid ref name."""


class HookError(Exception):
    """An error occurred while executing a hook."""


class WorkingTreeModifiedError(Exception):
    """Indicates that the working tree has modifications that would be overwritten."""