view rust/rhg/src/error.rs @ 51725:bbe59cc5d2e1

rust-changelog: accessing the index

The `Index` object is currently the one providing all DAG related
algorithms, starting with simple ancestors iteration up to more
advanced ones (ranges, common ancestors…).

From pure Rust code, there was no way to access the changelog index for
a given `Repository`, probably because `rhg` does not use any such algorithm
yet.

use crate::ui::utf8_to_local;
use crate::ui::UiError;
use crate::NoRepoInCwdError;
use format_bytes::format_bytes;
use hg::config::{ConfigError, ConfigParseError, ConfigValueParseError};
use hg::dirstate_tree::on_disk::DirstateV2ParseError;
use hg::errors::HgError;
use hg::exit_codes;
use hg::repo::RepoError;
use hg::revlog::RevlogError;
use hg::sparse::SparseConfigError;
use hg::utils::files::get_bytes_from_path;
use hg::utils::hg_path::HgPathError;
use hg::{DirstateError, DirstateMapError, PatternError, StatusError};
use std::convert::From;

/// The kind of command error
#[derive(Debug)]
pub enum CommandError {
    /// Exit with an error message and "standard" failure exit code.
    Abort {
        message: Vec<u8>,
        detailed_exit_code: exit_codes::ExitCode,
        hint: Option<Vec<u8>>,
    },

    /// Exit with a failure exit code but no message.
    Unsuccessful,

    /// Encountered something (such as a CLI argument, repository layout, …)
    /// not supported by this version of `rhg`. Depending on configuration
    /// `rhg` may attempt to silently fall back to Python-based `hg`, which
    /// may or may not support this feature.
    UnsupportedFeature { message: Vec<u8> },
    /// The fallback executable does not exist (or has some other problem if
    /// we end up being more precise about broken fallbacks).
    InvalidFallback { path: Vec<u8>, err: String },
}

impl CommandError {
    pub fn abort(message: impl AsRef<str>) -> Self {
        CommandError::abort_with_exit_code(message, exit_codes::ABORT)
    }

    pub fn abort_with_exit_code(
        message: impl AsRef<str>,
        detailed_exit_code: exit_codes::ExitCode,
    ) -> Self {
        CommandError::Abort {
            // TODO: bytes-based (instead of Unicode-based) formatting
            // of error messages to handle non-UTF-8 filenames etc:
            // https://www.mercurial-scm.org/wiki/EncodingStrategy#Mixing_output
            message: utf8_to_local(message.as_ref()).into(),
            detailed_exit_code,
            hint: None,
        }
    }

    pub fn abort_with_exit_code_and_hint(
        message: impl AsRef<str>,
        detailed_exit_code: exit_codes::ExitCode,
        hint: Option<impl AsRef<str>>,
    ) -> Self {
        CommandError::Abort {
            message: utf8_to_local(message.as_ref()).into(),
            detailed_exit_code,
            hint: hint.map(|h| utf8_to_local(h.as_ref()).into()),
        }
    }

    pub fn abort_with_exit_code_bytes(
        message: impl AsRef<[u8]>,
        detailed_exit_code: exit_codes::ExitCode,
    ) -> Self {
        // TODO: use this everywhere it makes sense instead of the string
        // version.
        CommandError::Abort {
            message: message.as_ref().into(),
            detailed_exit_code,
            hint: None,
        }
    }

    pub fn unsupported(message: impl AsRef<str>) -> Self {
        CommandError::UnsupportedFeature {
            message: utf8_to_local(message.as_ref()).into(),
        }
    }
}

/// For now we don’t differenciate between invalid CLI args and valid for `hg`
/// but not supported yet by `rhg`.
impl From<clap::Error> for CommandError {
    fn from(error: clap::Error) -> Self {
        CommandError::unsupported(error.to_string())
    }
}

impl From<HgError> for CommandError {
    fn from(error: HgError) -> Self {
        match error {
            HgError::UnsupportedFeature(message) => {
                CommandError::unsupported(message)
            }
            HgError::CensoredNodeError => {
                CommandError::unsupported("Encountered a censored node")
            }
            HgError::Abort {
                message,
                detailed_exit_code,
                hint,
            } => CommandError::abort_with_exit_code_and_hint(
                message,
                detailed_exit_code,
                hint,
            ),
            _ => CommandError::abort(error.to_string()),
        }
    }
}

impl From<ConfigValueParseError> for CommandError {
    fn from(error: ConfigValueParseError) -> Self {
        CommandError::abort_with_exit_code(
            error.to_string(),
            exit_codes::CONFIG_ERROR_ABORT,
        )
    }
}

impl From<UiError> for CommandError {
    fn from(_error: UiError) -> Self {
        // If we already failed writing to stdout or stderr,
        // writing an error message to stderr about it would be likely to fail
        // too.
        CommandError::abort("")
    }
}

impl From<RepoError> for CommandError {
    fn from(error: RepoError) -> Self {
        match error {
            RepoError::NotFound { at } => {
                CommandError::abort_with_exit_code_bytes(
                    format_bytes!(
                        b"abort: repository {} not found",
                        get_bytes_from_path(at)
                    ),
                    exit_codes::ABORT,
                )
            }
            RepoError::ConfigParseError(error) => error.into(),
            RepoError::Other(error) => error.into(),
        }
    }
}

impl<'a> From<&'a NoRepoInCwdError> for CommandError {
    fn from(error: &'a NoRepoInCwdError) -> Self {
        let NoRepoInCwdError { cwd } = error;
        CommandError::abort_with_exit_code_bytes(
            format_bytes!(
                b"abort: no repository found in '{}' (.hg not found)!",
                get_bytes_from_path(cwd)
            ),
            exit_codes::ABORT,
        )
    }
}

impl From<ConfigError> for CommandError {
    fn from(error: ConfigError) -> Self {
        match error {
            ConfigError::Parse(error) => error.into(),
            ConfigError::Other(error) => error.into(),
        }
    }
}

impl From<ConfigParseError> for CommandError {
    fn from(error: ConfigParseError) -> Self {
        let ConfigParseError {
            origin,
            line,
            message,
        } = error;
        let line_message = if let Some(line_number) = line {
            format_bytes!(b":{}", line_number.to_string().into_bytes())
        } else {
            Vec::new()
        };
        CommandError::abort_with_exit_code_bytes(
            format_bytes!(
                b"config error at {}{}: {}",
                origin,
                line_message,
                message
            ),
            exit_codes::CONFIG_ERROR_ABORT,
        )
    }
}

impl From<(RevlogError, &str)> for CommandError {
    fn from((err, rev): (RevlogError, &str)) -> CommandError {
        match err {
            RevlogError::WDirUnsupported => CommandError::abort(
                "abort: working directory revision cannot be specified",
            ),
            RevlogError::InvalidRevision => CommandError::abort(format!(
                "abort: invalid revision identifier: {}",
                rev
            )),
            RevlogError::AmbiguousPrefix => CommandError::abort(format!(
                "abort: ambiguous revision identifier: {}",
                rev
            )),
            RevlogError::Other(error) => error.into(),
        }
    }
}

impl From<StatusError> for CommandError {
    fn from(error: StatusError) -> Self {
        match error {
            StatusError::Pattern(_) => {
                CommandError::unsupported(format!("{}", error))
            }
            _ => CommandError::abort(format!("{}", error)),
        }
    }
}

impl From<HgPathError> for CommandError {
    fn from(error: HgPathError) -> Self {
        CommandError::unsupported(format!("{}", error))
    }
}

impl From<PatternError> for CommandError {
    fn from(error: PatternError) -> Self {
        CommandError::unsupported(format!("{}", error))
    }
}

impl From<DirstateMapError> for CommandError {
    fn from(error: DirstateMapError) -> Self {
        CommandError::abort(format!("{}", error))
    }
}

impl From<DirstateError> for CommandError {
    fn from(error: DirstateError) -> Self {
        match error {
            DirstateError::Common(error) => error.into(),
            DirstateError::Map(error) => error.into(),
        }
    }
}

impl From<DirstateV2ParseError> for CommandError {
    fn from(error: DirstateV2ParseError) -> Self {
        HgError::from(error).into()
    }
}

impl From<SparseConfigError> for CommandError {
    fn from(e: SparseConfigError) -> Self {
        match e {
            SparseConfigError::IncludesAfterExcludes { context } => {
                Self::abort_with_exit_code_bytes(
                    format_bytes!(
                        b"{} config cannot have includes after excludes",
                        context
                    ),
                    exit_codes::CONFIG_PARSE_ERROR_ABORT,
                )
            }
            SparseConfigError::EntryOutsideSection { context, line } => {
                Self::abort_with_exit_code_bytes(
                    format_bytes!(
                        b"{} config entry outside of section: {}",
                        context,
                        &line,
                    ),
                    exit_codes::CONFIG_PARSE_ERROR_ABORT,
                )
            }
            SparseConfigError::InvalidNarrowPrefix(prefix) => {
                Self::abort_with_exit_code_bytes(
                    format_bytes!(
                        b"invalid prefix on narrow pattern: {}",
                        &prefix
                    ),
                    exit_codes::ABORT,
                )
            }
            SparseConfigError::IncludesInNarrow => Self::abort(
                "including other spec files using '%include' \
                    is not supported in narrowspec",
            ),
            SparseConfigError::HgError(e) => Self::from(e),
            SparseConfigError::PatternError(e) => {
                Self::unsupported(format!("{}", e))
            }
        }
    }
}