use std::{
borrow::Cow,
env,
ffi::{
OsStr,
OsString,
},
io,
path::{
Path,
PathBuf,
},
str::FromStr,
};
use thiserror::Error;
#[remain::sorted]
#[derive(Debug, Error)]
pub enum CanonicalCommandError {
#[error("failed to canonicalize: {1}")]
Canonicalize(#[source] io::Error, PathBuf),
#[error("program not found on PATH: {0}")]
NotFound(String),
}
#[derive(Clone, Debug, Default, Eq, Hash, Ord, PartialEq, PartialOrd)]
pub struct CanonicalCommand(PathBuf);
impl CanonicalCommand {
#[must_use]
pub fn as_path(&self) -> &Path {
self.0.as_path()
}
}
impl AsRef<Path> for CanonicalCommand {
fn as_ref(&self) -> &Path {
self.0.as_path()
}
}
impl AsRef<OsStr> for CanonicalCommand {
fn as_ref(&self) -> &OsStr {
self.0.as_os_str()
}
}
impl From<CanonicalCommand> for PathBuf {
fn from(value: CanonicalCommand) -> Self {
value.0
}
}
impl TryFrom<Box<Path>> for CanonicalCommand {
type Error = CanonicalCommandError;
fn try_from(value: Box<Path>) -> Result<Self, Self::Error> {
let command = canonicalize_command(value.as_ref())?;
Ok(Self(command))
}
}
impl TryFrom<PathBuf> for CanonicalCommand {
type Error = CanonicalCommandError;
fn try_from(value: PathBuf) -> Result<Self, Self::Error> {
let command = canonicalize_command(value)?;
Ok(Self(command))
}
}
impl TryFrom<OsString> for CanonicalCommand {
type Error = CanonicalCommandError;
fn try_from(value: OsString) -> Result<Self, Self::Error> {
let command = canonicalize_command(value)?;
Ok(Self(command))
}
}
impl TryFrom<String> for CanonicalCommand {
type Error = CanonicalCommandError;
fn try_from(value: String) -> Result<Self, Self::Error> {
let command = canonicalize_command(value)?;
Ok(Self(command))
}
}
impl TryFrom<&str> for CanonicalCommand {
type Error = CanonicalCommandError;
fn try_from(value: &str) -> Result<Self, Self::Error> {
let command = canonicalize_command(value)?;
Ok(Self(command))
}
}
impl<'a> TryFrom<Cow<'a, Path>> for CanonicalCommand {
type Error = CanonicalCommandError;
fn try_from(value: Cow<'a, Path>) -> Result<Self, Self::Error> {
let command = canonicalize_command(value.as_ref())?;
Ok(Self(command))
}
}
impl FromStr for CanonicalCommand {
type Err = CanonicalCommandError;
fn from_str(s: &str) -> Result<Self, Self::Err> {
let command = canonicalize_command(s)?;
Ok(Self(command))
}
}
fn canonicalize_command(program: impl AsRef<OsStr>) -> Result<PathBuf, CanonicalCommandError> {
let found = find_command(program)?;
found
.canonicalize()
.map_err(|err| CanonicalCommandError::Canonicalize(err, found.clone()))
}
fn find_command(program: impl AsRef<OsStr>) -> Result<PathBuf, CanonicalCommandError> {
let path = Path::new(program.as_ref());
if path.is_file() {
Ok(path.to_path_buf())
} else {
#[allow(clippy::disallowed_methods)] // We use `$PATH` lookup to find the command
env::split_paths(&env::var("PATH").unwrap_or_else(|_| "".to_string()))
.map(|path| path.join(program.as_ref()))
.find(|candidate| candidate.is_file())
.ok_or_else(|| {
CanonicalCommandError::NotFound(program.as_ref().to_string_lossy().to_string())
})
}
}
