use std::{    borrow::Cow,    ffi::OsString,    path::{Path, PathBuf},}; use crate::Source; /// The category of a [`Source`], in order of ascending precedence.#[derive(Clone, Copy, Debug, Eq, PartialEq, Hash, Ord, PartialOrd)]pub enum Kind {    /// A special configuration file that ships with the git installation, and is thus tied to the used git binary.    GitInstallation,    /// A source shared for the entire system.    System,    /// Application specific configuration unique for each user of the `System`.    Global,    /// Configuration relevant only to the repository, possibly including the worktree.    Repository,    /// Configuration specified after all other configuration was loaded for the purpose of overrides.    Override,} impl Kind {    /// Return a list of sources associated with this `Kind` of source, in order of ascending precedence.    pub fn sources(self) -> &'static [Source] {        let src = match self {            Kind::GitInstallation => &[Source::GitInstallation] as &[_],            Kind::System => &[Source::System],            Kind::Global => &[Source::Git, Source::User],            Kind::Repository => &[Source::Local, Source::Worktree],            Kind::Override => &[Source::Env, Source::Cli, Source::Api],        };        debug_assert!(            src.iter().all(|src| src.kind() == self),            "BUG: classification of source has to match the ordering here, see `Source::kind()`"        );        src    }} impl Source {    /// Return true if the source indicates a location within a file of a repository.    pub const fn kind(self) -> Kind {        use Source::*;        match self {            GitInstallation => Kind::GitInstallation,            System => Kind::System,            Git | User => Kind::Global,            Local | Worktree => Kind::Repository,            Env | Cli | Api => Kind::Override,        }    }     /// Returns the location at which a file of this type would be stored, or `None` if    /// there is no notion of persistent storage for this source, with `env_var` to obtain environment variables.    /// Note that the location can be relative for repository-local sources like `Local` and `Worktree`,    /// and the caller has to known which base it it relative to, namely the `common_dir` in the `Local` case    /// and the `git_dir` in the `Worktree` case.    /// Be aware that depending on environment overrides, multiple scopes might return the same path, which should    /// only be loaded once nonetheless.    ///    /// With `env_var` it becomes possible to prevent accessing environment variables entirely to comply with `git-sec`    /// permissions for example.    pub fn storage_location(self, env_var: &mut dyn FnMut(&str) -> Option<OsString>) -> Option<Cow<'static, Path>> {        use Source::*;        match self {            GitInstallation => git::install_config_path().map(git_path::from_bstr),            System => env_var("GIT_CONFIG_NO_SYSTEM")                .is_none()                .then(|| PathBuf::from(env_var("GIT_CONFIG_SYSTEM").unwrap_or_else(|| "/etc/gitconfig".into())).into()),            Git => match env_var("GIT_CONFIG_GLOBAL") {                Some(global_override) => Some(PathBuf::from(global_override).into()),                None => env_var("XDG_CONFIG_HOME")                    .map(|home| {                        let mut p = PathBuf::from(home);                        p.push("git");                        p.push("config");                        p                    })                    .or_else(|| {                        env_var("HOME").map(|home| {                            let mut p = PathBuf::from(home);                            p.push(".config");                            p.push("git");                            p.push("config");                            p                        })                    })                    .map(Cow::Owned),            },            User => env_var("GIT_CONFIG_GLOBAL")                .map(|global_override| PathBuf::from(global_override).into())                .or_else(|| {                    env_var("HOME").map(|home| {                        let mut p = PathBuf::from(home);                        p.push(".gitconfig");                        p.into()                    })                }),            Local => Some(Path::new("config").into()),            Worktree => Some(Path::new("config.worktree").into()),            Env | Cli | Api => None,        }    }} /// Environment information involving the `git` program itself.mod git {    use std::process::{Command, Stdio};     use bstr::{BStr, BString, ByteSlice};     /// Returns the file that contains git configuration coming with the installation of the `git` file in the current `PATH`, or `None`    /// if no `git` executable was found or there were other errors during execution.    pub fn install_config_path() -> Option<&'static BStr> {        static PATH: once_cell::sync::Lazy<Option<BString>> = once_cell::sync::Lazy::new(|| {            let mut cmd = Command::new(if cfg!(windows) { "git.exe" } else { "git" });            cmd.args(["config", "-l", "--show-origin"])                .stdin(Stdio::null())                .stderr(Stdio::null());            first_file_from_config_with_origin(cmd.output().ok()?.stdout.as_slice().into()).map(ToOwned::to_owned)        });        PATH.as_ref().map(|b| b.as_ref())    }     fn first_file_from_config_with_origin(source: &BStr) -> Option<&BStr> {        let file = source.strip_prefix(b"file:")?;        let end_pos = file.find_byte(b'\t')?;        file[..end_pos].as_bstr().into()    }     #[cfg(test)]    mod tests {        #[test]        fn first_file_from_config_with_origin() {            let macos = "file:/Applications/Xcode.app/Contents/Developer/usr/share/git-core/gitconfig	credential.helper=osxkeychain\nfile:/Users/byron/.gitconfig	push.default=simple\n";            let win_msys =                "file:C:/git-sdk-64/etc/gitconfig	core.symlinks=false\r\nfile:C:/git-sdk-64/etc/gitconfig	core.autocrlf=true";            let win_cmd = "file:C:/Program Files/Git/etc/gitconfig	diff.astextplain.textconv=astextplain\r\nfile:C:/Program Files/Git/etc/gitconfig	filter.lfs.clean=git-lfs clean -- %f\r\n";            let linux = "file:/home/parallels/.gitconfig	core.excludesfile=~/.gitignore\n";            let bogus = "something unexpected";            let empty = "";             for (source, expected) in [                (                    macos,                    Some("/Applications/Xcode.app/Contents/Developer/usr/share/git-core/gitconfig"),                ),                (win_msys, Some("C:/git-sdk-64/etc/gitconfig")),                (win_cmd, Some("C:/Program Files/Git/etc/gitconfig")),                (linux, Some("/home/parallels/.gitconfig")),                (bogus, None),                (empty, None),            ] {                assert_eq!(                    super::first_file_from_config_with_origin(source.into()),                    expected.map(Into::into)                );            }        }    }}