vmstat: more tests

Author: Bluemangoo

tests/by-util/test_vmstat.rs

@@ -3,6 +3,7 @@
 // For the full copyright and license information, please view the LICENSE
 // file that was distributed with this source code.
 
+use std::time::Duration;
 use uutests::new_ucmd;
 use uutests::util::TestScenario;
 use uutests::util_name;
@@ -17,6 +18,12 @@ fn test_invalid_arg() {
     new_ucmd!().arg("--definitely-invalid").fails().code_is(1);
 }
 
+#[test]
+fn test_invalid_number() {
+    new_ucmd!().arg("-1").fails().code_is(1);
+    new_ucmd!().arg("0").fails().code_is(1);
+}
+
 #[test]
 fn test_unit() {
     new_ucmd!().args(&["-S", "M"]).succeeds();
@@ -27,3 +34,37 @@ fn test_unit() {
 fn test_invalid_unit() {
     new_ucmd!().args(&["-S", "x"]).fails().code_is(1);
 }
+
+#[test]
+#[cfg(target_os = "linux")]
+fn test_header() {
+    let result = new_ucmd!().succeeds();
+    assert!(result.stdout_str().starts_with("procs"));
+}
+
+#[test]
+#[cfg(target_os = "linux")]
+fn test_wide_mode() {
+    let result = new_ucmd!().arg("-w").succeeds();
+    assert!(result.stdout_str().starts_with("--procs--"));
+}
+
+#[test]
+#[cfg(target_os = "linux")]
+fn test_no_first() {
+    let time = std::time::Instant::now();
+    new_ucmd!().arg("-y").succeeds();
+    assert!(time.elapsed() >= Duration::from_secs(1));
+}
+
+#[test]
+#[cfg(target_os = "linux")]
+fn test_active() {
+    let result = new_ucmd!().arg("-a").succeeds();
+    assert!(result
+        .stdout_str()
+        .lines()
+        .nth(1)
+        .unwrap()
+        .contains("active"));
+}