Add UError impl for clap::Error

src/uu/cp/src/cp.rs

@@ -475,7 +475,7 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
             LONG_HELP,
             backup_control::BACKUP_CONTROL_LONG_HELP
         ))
-        .get_matches_from(args);
+        .try_get_matches_from(args)?;
 
     let options = Options::from_matches(&matches)?;
 

src/uucore/src/lib/mods/error.rs

@@ -50,6 +50,7 @@
 
 // spell-checker:ignore uioerror
 
+use clap;
 use std::{
     error::Error,
     fmt::{Display, Formatter},
@@ -615,3 +616,13 @@ impl From<i32> for Box<dyn UError> {
         ExitCode::new(i)
     }
 }
+
+/// Implementations for clap::Error
+impl UError for clap::Error {
+    fn code(&self) -> i32 {
+        match self.kind {
+            clap::ErrorKind::DisplayHelp | clap::ErrorKind::DisplayVersion => 0,
+            _ => 1,
+        }
+    }
+}

tests/by-util/test_cp.rs

@@ -190,7 +190,7 @@ fn test_cp_target_directory_is_file() {
         .arg(TEST_HOW_ARE_YOU_SOURCE)
         .arg(TEST_HELLO_WORLD_SOURCE)
         .fails()
-        .stderr_contains("must specify a directory");
+        .stderr_contains(format!("'{}' is not a directory", TEST_HOW_ARE_YOU_SOURCE));
 }
 
 #[test]