tests/pinky: add --lookup test

tests/by-util/test_pinky.rs

@@ -90,6 +90,19 @@ fn test_short_format_i() {
     assert_eq!(v_actual, v_expect);
 }
 
+#[cfg(unix)]
+#[test]
+#[cfg(not(target_os = "openbsd"))]
+fn test_lookup() {
+    let args = ["--lookup"];
+    let ts = TestScenario::new(util_name!());
+    let actual = ts.ucmd().args(&args).succeeds().stdout_move_str();
+    let expect = unwrap_or_return!(expected_result(&ts, &[])).stdout_move_str();
+    let v_actual: Vec<&str> = actual.split_whitespace().collect();
+    let v_expect: Vec<&str> = expect.split_whitespace().collect();
+    assert_eq!(v_actual, v_expect);
+}
+
 #[cfg(unix)]
 #[test]
 #[cfg(not(target_os = "openbsd"))]