Rollup merge of rust-lang#36631 - frewsxcv:dir-entry-debug, r=sfackler

Implement Debug for DirEntry.

None

src/libstd/fs.rs

@@ -1055,6 +1055,15 @@ impl DirEntry {
     }
 }
 
+#[stable(feature = "dir_entry_debug", since = "1.13.0")]
+impl fmt::Debug for DirEntry {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        f.debug_tuple("DirEntry")
+            .field(&self.path())
+            .finish()
+    }
+}
+
 impl AsInner<fs_imp::DirEntry> for DirEntry {
     fn as_inner(&self) -> &fs_imp::DirEntry { &self.0 }
 }
@@ -2641,6 +2650,18 @@ mod tests {
         }
     }
 
+    #[test]
+    fn dir_entry_debug() {
+        let tmpdir = tmpdir();
+        let file_path = &tmpdir.join("b");
+        File::create(file_path).unwrap();
+        let mut read_dir = tmpdir.path().read_dir().unwrap();
+        let dir_entry = read_dir.next().unwrap().unwrap();
+        let actual = format!("{:?}", dir_entry);
+        let expected = format!("DirEntry(\"{}\")", file_path.display());
+        assert_eq!(actual, expected);
+    }
+
     #[test]
     fn read_dir_not_found() {
         let res = fs::read_dir("/path/that/does/not/exist");