1 files changed, 29 insertions, 0 deletions
diff --git a/toolkit/modules/tests/xpcshell/test_ObjectUtils_strict.js b/toolkit/modules/tests/xpcshell/test_ObjectUtils_strict.js
new file mode 100644
index 0000000000..bd5698ee04
--- /dev/null
+++ b/toolkit/modules/tests/xpcshell/test_ObjectUtils_strict.js
@@ -0,0 +1,29 @@
+"use strict";
+
+var { ObjectUtils } = ChromeUtils.import(
+  "resource://gre/modules/ObjectUtils.jsm"
+);
+var { PromiseTestUtils } = ChromeUtils.importESModule(
+  "resource://testing-common/PromiseTestUtils.sys.mjs"
+);
+
+add_task(async function test_strict() {
+  let loose = { a: 1 };
+  let strict = ObjectUtils.strict(loose);
+
+  loose.a; // Should not throw.
+  loose.b || undefined; // Should not throw.
+
+  strict.a; // Should not throw.
+  PromiseTestUtils.expectUncaughtRejection(/No such property: "b"/);
+  Assert.throws(() => strict.b, /No such property: "b"/);
+  "b" in strict; // Should not throw.
+  strict.b = 2;
+  strict.b; // Should not throw.
+
+  PromiseTestUtils.expectUncaughtRejection(/No such property: "c"/);
+  Assert.throws(() => strict.c, /No such property: "c"/);
+  "c" in strict; // Should not throw.
+  loose.c = 3;
+  strict.c; // Should not throw.
+});