CLI: cover invalid Windows arguments

apps/lightcraft-cli/src/main.rs

@@ -160,7 +160,7 @@ fn main() -> ExitCode {
         match arg.into_string() {
             Ok(arg) => args.push(arg),
             Err(_) => {
-                eprintln!("lightcraft-cli: argument {} is not valid UTF-8; use a UTF-8 encoded argument", index + 1);
+                eprintln!("lightcraft-cli: argument {} is not valid Unicode", index + 1);
                 return ExitCode::FAILURE;
             }
         }

apps/lightcraft-cli/tests/it/cli.rs

@@ -174,7 +174,26 @@ fn non_utf8_argument_fails_without_a_panic() {
     let stderr = String::from_utf8_lossy(&output.stderr);
     assert_eq!(output.status.code(), Some(1), "{stderr}");
     assert!(stderr.contains("argument 2"), "{stderr}");
-    assert!(stderr.contains("UTF-8"), "{stderr}");
+    assert!(stderr.contains("is not valid Unicode"), "{stderr}");
+    assert!(!stderr.contains("panicked"), "{stderr}");
+    assert!(!out.exists());
+    assert!(Command::new(binary()).arg("--version").status().unwrap().success());
+}
+
+#[cfg(windows)]
+#[test]
+fn non_unicode_argument_fails_without_a_panic_on_windows() {
+    use std::ffi::OsString;
+    use std::os::windows::ffi::OsStringExt;
+
+    let out = tmp("non-unicode-output.png");
+    let _ = std::fs::remove_file(&out);
+    let name: Vec<u16> = "bad-".encode_utf16().chain([0xD800]).chain(".png".encode_utf16()).collect();
+    let output = Command::new(binary()).arg("render").arg(OsString::from_wide(&name)).arg("-o").arg(&out).output().unwrap();
+    let stderr = String::from_utf8_lossy(&output.stderr);
+    assert_eq!(output.status.code(), Some(1), "{stderr}");
+    assert!(stderr.contains("argument 2"), "{stderr}");
+    assert!(stderr.contains("is not valid Unicode"), "{stderr}");
     assert!(!stderr.contains("panicked"), "{stderr}");
     assert!(!out.exists());
     assert!(Command::new(binary()).arg("--version").status().unwrap().success());