tests ~ reorganize tests

tests/by-util/test_realpath.rs

@@ -0,0 +1,34 @@
+use crate::common::util::*;
+
+#[test]
+fn test_current_directory() {
+    let (at, mut ucmd) = at_and_ucmd!();
+    let actual = ucmd.arg(".").run().stdout;
+    let expect = at.root_dir_resolved() + "\n";
+    println!("actual: {:?}", actual);
+    println!("expect: {:?}", expect);
+    assert_eq!(actual, expect);
+}
+
+#[test]
+fn test_long_redirection_to_current_dir() {
+    let (at, mut ucmd) = at_and_ucmd!();
+    // Create a 256-character path to current directory
+    let dir = path_concat!(".", ..128);
+    let actual = ucmd.arg(dir).run().stdout;
+    let expect = at.root_dir_resolved() + "\n";
+    println!("actual: {:?}", actual);
+    println!("expect: {:?}", expect);
+    assert_eq!(actual, expect);
+}
+
+#[test]
+fn test_long_redirection_to_root() {
+    // Create a 255-character path to root
+    let dir = path_concat!("..", ..85);
+    let actual = new_ucmd!().arg(dir).run().stdout;
+    let expect = get_root_path().to_owned() + "\n";
+    println!("actual: {:?}", actual);
+    println!("expect: {:?}", expect);
+    assert_eq!(actual, expect);
+}