tests: improve error messages for exit statuses

Author: andreacorbellini

tests/uutests/src/lib/util.rs

@@ -406,7 +406,9 @@ impl CmdResult {
     /// Returns the program's exit code
     /// Panics if not run or has not finished yet for example when run with `run_no_wait()`
     pub fn code(&self) -> i32 {
-        self.exit_status().code().unwrap()
+        let s = self.exit_status();
+        s.code()
+            .unwrap_or_else(|| panic!("Program did not exit with a status code: {s:?}"))
     }
 
     /// Verify the exit code of the program
@@ -418,15 +420,29 @@ impl CmdResult {
     /// ```
     #[track_caller]
     pub fn code_is(&self, expected_code: i32) -> &Self {
-        let fails = self.code() != expected_code;
+        let fails = self.exit_status().code() != Some(expected_code);
         if fails {
             eprintln!(
                 "stdout:\n{}\nstderr:\n{}",
                 self.stdout_str(),
                 self.stderr_str()
             );
         }
-        assert_eq!(self.code(), expected_code);
+        #[cfg(unix)]
+        assert_eq!(
+            self.exit_status().code(),
+            Some(expected_code),
+            "exit code: {:?}; signal: {:?}",
+            self.exit_status().code(),
+            self.exit_status().signal(),
+        );
+        #[cfg(not(unix))]
+        assert_eq!(
+            self.exit_status().code(),
+            Some(expected_code),
+            "exit code: {:?}",
+            self.exit_status().code(),
+        );
         self
     }