Fix name of special directories

Author: KSXGitHub

src/fs_tree_builder.rs

@@ -4,6 +4,7 @@ use super::{
     reporter::{error_report::Operation::*, ErrorReport, Event, Reporter},
     size::Size,
     tree_builder::{Info, TreeBuilder},
+    utils::path_name,
 };
 use pipe_trait::Pipe;
 use std::{
@@ -42,10 +43,7 @@ where
         } = builder;
 
         TreeBuilder::<PathBuf, OsStringDisplay, Data, _, _> {
-            name: root.file_name().map_or_else(
-                || ".".pipe(OsStringDisplay::os_string_from),
-                OsStringDisplay::os_string_from,
-            ),
+            name: path_name(&root),
 
             path: root,
 

src/lib.rs

@@ -1,5 +1,7 @@
 #![deny(warnings)]
 
+mod utils;
+
 pub mod app;
 pub mod args;
 pub mod bytes_format;

src/utils.rs

@@ -0,0 +1,88 @@
+use super::os_string_display::OsStringDisplay;
+use std::path::{Component::*, Path};
+
+/// Get file name or directory name of a path.
+pub fn path_name(path: &Path) -> OsStringDisplay {
+    match path.components().last() {
+        None | Some(CurDir) => OsStringDisplay::os_string_from("."),
+        Some(RootDir) => OsStringDisplay::os_string_from("/"),
+        Some(Normal(name)) => OsStringDisplay::os_string_from(name),
+        Some(Prefix(prefix)) => OsStringDisplay::os_string_from(prefix.as_os_str()),
+        Some(ParentDir) => OsStringDisplay::os_string_from(path),
+    }
+}
+
+#[cfg(test)]
+use pretty_assertions::assert_eq;
+#[cfg(test)]
+use std::path::PathBuf;
+
+#[test]
+fn empty() {
+    let actual = path_name(&PathBuf::new());
+    let expected = OsStringDisplay::os_string_from(".");
+    assert_eq!(actual, expected);
+}
+
+#[test]
+fn current_dir() {
+    let actual = path_name(&PathBuf::from("."));
+    let expected = OsStringDisplay::os_string_from(".");
+    assert_eq!(actual, expected);
+}
+
+#[cfg(unix)]
+#[test]
+fn root_dir() {
+    let actual = path_name(&PathBuf::from("/"));
+    let expected = OsStringDisplay::os_string_from("/");
+    assert_eq!(actual, expected);
+}
+
+#[cfg(windows)]
+#[test]
+fn root_dir() {
+    let actual = path_name(&PathBuf::from("C:\\"));
+    let expected = OsStringDisplay::os_string_from("c:");
+    assert_eq!(actual, expected);
+}
+
+#[cfg(unix)]
+#[test]
+fn normal_relative() {
+    let actual = path_name(&PathBuf::from("abc/def/ghi"));
+    let expected = OsStringDisplay::os_string_from("ghi");
+    assert_eq!(actual, expected);
+}
+
+#[cfg(unix)]
+#[test]
+fn normal_absolute() {
+    let actual = path_name(&PathBuf::from("/abc/def/ghi"));
+    let expected = OsStringDisplay::os_string_from("ghi");
+    assert_eq!(actual, expected);
+}
+
+#[cfg(unix)]
+#[test]
+fn normal_trailing_separator() {
+    let actual = path_name(&PathBuf::from("abc/def/ghi/"));
+    let expected = OsStringDisplay::os_string_from("ghi");
+    assert_eq!(actual, expected);
+}
+
+#[cfg(unix)]
+#[test]
+fn parent_dir() {
+    let actual = path_name(&PathBuf::from(".."));
+    let expected = OsStringDisplay::os_string_from("..");
+    assert_eq!(actual, expected);
+}
+
+#[cfg(unix)]
+#[test]
+fn grandparent_dir() {
+    let actual = path_name(&PathBuf::from("../.."));
+    let expected = OsStringDisplay::os_string_from("../..");
+    assert_eq!(actual, expected);
+}