Update.

test/tempfile/mkdtemp.wren

@@ -0,0 +1,18 @@
+// retoor <retoor@molodetz.nl>
+
+import "tempfile" for TempFile
+import "io" for Directory
+import "pathlib" for Path
+
+var dir = TempFile.mkdtemp()
+System.print(dir is String) // expect: true
+System.print(Path.new(dir).exists()) // expect: true
+System.print(Path.new(dir).isDir()) // expect: true
+
+Directory.delete(dir)
+System.print(Path.new(dir).exists()) // expect: false
+
+var dir2 = TempFile.mkdtemp("_end", "mydir_")
+System.print(dir2.contains("mydir_")) // expect: true
+System.print(dir2.endsWith("_end")) // expect: true
+Directory.delete(dir2)