shuf: move from getopts to clap (#1950)

tests/by-util/test_shuf.rs

@@ -1 +1,55 @@
-// ToDO: add tests
+// ToDO: add more tests
+
+use crate::common::util::*;
+
+#[test]
+fn test_shuf_echo_and_input_range_not_allowed() {
+    let result = new_ucmd!().args(&["-e", "0", "-i", "0-2"]).run();
+
+    assert!(!result.success);
+    assert!(result
+        .stderr
+        .contains("The argument '--input-range <LO-HI>' cannot be used with '--echo <ARG>...'"));
+}
+
+#[test]
+fn test_shuf_input_range_and_file_not_allowed() {
+    let result = new_ucmd!().args(&["-i", "0-9", "file"]).run();
+
+    assert!(!result.success);
+    assert!(result
+        .stderr
+        .contains("The argument '<file>' cannot be used with '--input-range <LO-HI>'"));
+}
+
+#[test]
+fn test_shuf_invalid_input_range_one() {
+    let result = new_ucmd!().args(&["-i", "0"]).run();
+
+    assert!(!result.success);
+    assert!(result.stderr.contains("invalid input range"));
+}
+
+#[test]
+fn test_shuf_invalid_input_range_two() {
+    let result = new_ucmd!().args(&["-i", "a-9"]).run();
+
+    assert!(!result.success);
+    assert!(result.stderr.contains("invalid input range: 'a'"));
+}
+
+#[test]
+fn test_shuf_invalid_input_range_three() {
+    let result = new_ucmd!().args(&["-i", "0-b"]).run();
+
+    assert!(!result.success);
+    assert!(result.stderr.contains("invalid input range: 'b'"));
+}
+
+#[test]
+fn test_shuf_invalid_input_line_count() {
+    let result = new_ucmd!().args(&["-n", "a"]).run();
+
+    assert!(!result.success);
+    assert!(result.stderr.contains("invalid line count: 'a'"));
+}