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#![allow(unknown_lints)]
use std::{env, ffi::OsStr};
const LC_ALL: &str = "LC_ALL";
const LC_CTYPE: &str = "LC_CTYPE";
const LANG: &str = "LANG";
/// Environment variable access abstraction to allow testing without
/// mutating env variables.
///
/// Use [StdEnv] to query [std::env]
trait EnvAccess {
/// See also [std::env::var]
fn get(&self, key: impl AsRef<OsStr>) -> Option<String>;
}
/// Proxy to [std::env]
struct StdEnv;
impl EnvAccess for StdEnv {
fn get(&self, key: impl AsRef<OsStr>) -> Option<String> {
env::var(key).ok()
}
}
pub(crate) fn get() -> impl Iterator<Item = String> {
_get(&StdEnv).into_iter()
}
fn _get(env: &impl EnvAccess) -> Option<String> {
let code = env
.get(LC_ALL)
.or_else(|| env.get(LC_CTYPE))
.or_else(|| env.get(LANG))?;
parse_locale_code(&code)
}
fn parse_locale_code(code: &str) -> Option<String> {
// Some locales are returned with the char encoding too: `en_US.UTF-8`
// TODO: Once we bump MSRV >= 1.52, remove this allow and clean up
#[allow(clippy::manual_split_once)]
#[allow(clippy::needless_splitn)]
code.splitn(2, '.').next().map(|s| s.replace('_', "-"))
}
#[cfg(test)]
mod tests {
use super::{parse_locale_code, EnvAccess, _get, LANG, LC_ALL, LC_CTYPE};
use std::{
collections::HashMap,
ffi::{OsStr, OsString},
};
type MockEnv = HashMap<OsString, String>;
impl EnvAccess for MockEnv {
fn get(&self, key: impl AsRef<OsStr>) -> Option<String> {
self.get(key.as_ref()).cloned()
}
}
const PARSE_LOCALE: &str = "fr-FR";
const LANG_PARSE_LOCALE: &str = "fr_FR";
#[test]
fn parse_identifier() {
let identifier = "fr_FR.UTF-8";
assert_eq!(parse_locale_code(identifier).as_deref(), Some(PARSE_LOCALE));
}
#[test]
fn parse_non_suffixed_identifier() {
assert_eq!(
parse_locale_code(PARSE_LOCALE).as_deref(),
Some(PARSE_LOCALE)
);
assert_eq!(
parse_locale_code(LANG_PARSE_LOCALE).as_deref(),
Some(PARSE_LOCALE)
);
}
#[test]
fn env_priority() {
let mut env = MockEnv::new();
assert_eq!(_get(&env), None);
// These locale names are technically allowed and some systems may still
// defined aliases such as these but the glibc sources mention that this
// should be considered deprecated
env.insert(LANG.into(), "invalid".to_owned());
assert_eq!(_get(&env).as_deref(), Some("invalid"));
env.insert(LC_CTYPE.into(), "invalid-also".to_owned());
assert_eq!(_get(&env).as_deref(), Some("invalid-also"));
env.insert(LC_ALL.into(), "invalid-again".to_owned());
assert_eq!(_get(&env).as_deref(), Some("invalid-again"));
}
}