2 files changed, 17 insertions, 0 deletions
diff --git a/cli/js/tests/umask_test.ts b/cli/js/tests/umask_test.ts
new file mode 100644
index 000000000..543372a46
--- /dev/null
+++ b/cli/js/tests/umask_test.ts
@@ -0,0 +1,16 @@
+// Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
+import { unitTest, assertEquals } from "./test_util.ts";
+
+unitTest(
+  {
+    skip: Deno.build.os === "win"
+  },
+  function umaskSuccess(): void {
+    const prevMask = Deno.umask(0o020);
+    const newMask = Deno.umask(prevMask);
+    const finalMask = Deno.umask();
+    assertEquals(newMask, 0o020);
+    assertEquals(finalMask, prevMask);
+    assertEquals(prevMask, 0o022);
+  }
+);
diff --git a/cli/js/tests/unit_tests.ts b/cli/js/tests/unit_tests.ts
index cc51e6ade..9ae724d53 100644
--- a/cli/js/tests/unit_tests.ts
+++ b/cli/js/tests/unit_tests.ts
@@ -57,6 +57,7 @@ import "./timers_test.ts";
 import "./tls_test.ts";
 import "./truncate_test.ts";
 import "./tty_test.ts";
+import "./umask_test.ts";
 import "./url_test.ts";
 import "./url_search_params_test.ts";
 import "./utime_test.ts";