tests: use setup_test_locale helper in chown, dd, and df

src/uu/chown/src/chown.rs

@@ -236,15 +236,11 @@ fn parse_spec(spec: &str, sep: char) -> UResult<(Option<u32>, Option<u32>)> {
 #[cfg(test)]
 mod test {
     use super::*;
-    use std::env;
     use uucore::locale;
 
     #[test]
     fn test_parse_spec() {
-        unsafe {
-            env::set_var("LANG", "C");
-        }
-        let _ = locale::setup_localization("chown");
+        let _ = locale::setup_test_locale("chown");
         assert!(matches!(parse_spec(":", ':'), Ok((None, None))));
         assert!(matches!(parse_spec(".", ':'), Ok((None, None))));
         assert!(matches!(parse_spec(".", '.'), Ok((None, None))));

src/uu/dd/src/progress.rs

@@ -513,17 +513,13 @@ pub(crate) fn gen_prog_updater(
 
 #[cfg(test)]
 mod tests {
-    use std::env;
     use std::io::Cursor;
     use std::time::Duration;
-    use uucore::locale::setup_localization;
+    use uucore::locale::setup_test_locale;
 
     use super::{ProgUpdate, ReadStat, WriteStat};
     fn init() {
-        unsafe {
-            env::set_var("LANG", "C");
-        }
-        let _ = setup_localization("dd");
+        let _ = setup_test_locale("dd");
     }
 
     fn prog_update_write(n: u128) -> ProgUpdate {

src/uu/df/src/table.rs

@@ -573,7 +573,6 @@ impl Table {
 mod tests {
 
     use std::vec;
-    use uucore::locale::setup_localization;
 
     use crate::blocks::HumanReadable;
     use crate::columns::Column;
@@ -581,10 +580,7 @@ mod tests {
     use crate::{BlockSize, Options};
 
     fn init() {
-        unsafe {
-            std::env::set_var("LANG", "C");
-        }
-        let _ = setup_localization("df");
+        let _ = uucore::locale::setup_test_locale("df");
     }
 
     const COLUMNS_WITH_FS_TYPE: [Column; 7] = [