Add Deno.umask (#4290)

5 files changed, 38 insertions, 0 deletions

diff --git a/cli/js/deno.ts b/cli/js/deno.ts
index 23fcfda5d..f0115f261 100644
--- a/cli/js/deno.ts
+++ b/cli/js/deno.ts
@@ -113,6 +113,7 @@ export { symlinkSync, symlink } from "./ops/fs/symlink.ts";
 export { connectTLS, listenTLS } from "./tls.ts";
 export { truncateSync, truncate } from "./ops/fs/truncate.ts";
 export { isatty, setRaw } from "./ops/tty.ts";
+export { umask } from "./ops/fs/umask.ts";
 export { utimeSync, utime } from "./ops/fs/utime.ts";
 export { version } from "./version.ts";
 export { writeFileSync, writeFile, WriteFileOptions } from "./write_file.ts";
diff --git a/cli/js/lib.deno.ns.d.ts b/cli/js/lib.deno.ns.d.ts
index 8eb2e1f4d..6950d9050 100644
--- a/cli/js/lib.deno.ns.d.ts
+++ b/cli/js/lib.deno.ns.d.ts
@@ -287,6 +287,14 @@ declare namespace Deno {
    */
   export function chdir(directory: string): void;
 
+  /**
+   * **UNSTABLE**: New API. Maybe needs permissions.
+   *
+   * If `mask` is provided, sets the process umask. Always returns what the umask
+   * was before the call.
+   */
+  export function umask(mask?: number): number;
+
   /** **UNSTABLE**: might move to `Deno.symbols`. */
   export const EOF: unique symbol;
   export type EOF = typeof EOF;
diff --git a/cli/js/ops/fs/umask.ts b/cli/js/ops/fs/umask.ts
new file mode 100644
index 000000000..ee56fecb5
--- /dev/null
+++ b/cli/js/ops/fs/umask.ts
@@ -0,0 +1,12 @@
+// Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
+import { sendSync } from "../dispatch_json.ts";
+
+/**
+ * **UNSTABLE**: maybe needs `allow-env` permissions.
+ *
+ * If `mask` is provided, sets the process umask. Always returns what the umask
+ * was before the call.
+ */
+export function umask(mask?: number): number {
+  return sendSync("op_umask", { mask });
+}
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";