api: add convenience sort routines

This commit adds sort_by_key and sort_by_file_name convenience routines
for common sorting needs. The signature for sort_by_key in particular
mirrors the eponymous method on slices in the standard library.

Closes #147

1 files changed, 44 insertions, 1 deletions

diff --git a/src/tests/recursive.rs b/src/tests/recursive.rs
index bbb1ce1..4119f46 100644
--- a/src/tests/recursive.rs
+++ b/src/tests/recursive.rs
@@ -879,7 +879,7 @@ fn filter_entry() {
 }
 
 #[test]
-fn sort() {
+fn sort_by() {
     let dir = Dir::tmp();
     dir.mkdirp("foo/bar/baz/abc");
     dir.mkdirp("quux");
@@ -901,6 +901,49 @@ fn sort() {
 }
 
 #[test]
+fn sort_by_key() {
+    let dir = Dir::tmp();
+    dir.mkdirp("foo/bar/baz/abc");
+    dir.mkdirp("quux");
+
+    let wd =
+        WalkDir::new(dir.path()).sort_by_key(|a| a.file_name().to_owned());
+    let r = dir.run_recursive(wd);
+    r.assert_no_errors();
+
+    let expected = vec![
+        dir.path().to_path_buf(),
+        dir.join("foo"),
+        dir.join("foo").join("bar"),
+        dir.join("foo").join("bar").join("baz"),
+        dir.join("foo").join("bar").join("baz").join("abc"),
+        dir.join("quux"),
+    ];
+    assert_eq!(expected, r.paths());
+}
+
+#[test]
+fn sort_by_file_name() {
+    let dir = Dir::tmp();
+    dir.mkdirp("foo/bar/baz/abc");
+    dir.mkdirp("quux");
+
+    let wd = WalkDir::new(dir.path()).sort_by_file_name();
+    let r = dir.run_recursive(wd);
+    r.assert_no_errors();
+
+    let expected = vec![
+        dir.path().to_path_buf(),
+        dir.join("foo"),
+        dir.join("foo").join("bar"),
+        dir.join("foo").join("bar").join("baz"),
+        dir.join("foo").join("bar").join("baz").join("abc"),
+        dir.join("quux"),
+    ];
+    assert_eq!(expected, r.paths());
+}
+
+#[test]
 fn sort_max_open() {
     let dir = Dir::tmp();
     dir.mkdirp("foo/bar/baz/abc");