1 files changed, 28 insertions, 0 deletions
diff --git a/js/src/tests/test262/built-ins/Temporal/PlainDateTime/prototype/daysInYear/builtin-calendar-no-observable-calls.js b/js/src/tests/test262/built-ins/Temporal/PlainDateTime/prototype/daysInYear/builtin-calendar-no-observable-calls.js
new file mode 100644
index 0000000000..70cbdd66f8
--- /dev/null
+++ b/js/src/tests/test262/built-ins/Temporal/PlainDateTime/prototype/daysInYear/builtin-calendar-no-observable-calls.js
@@ -0,0 +1,28 @@
+// |reftest| skip-if(!this.hasOwnProperty('Temporal')) -- Temporal is not enabled unconditionally
+// Copyright (C) 2023 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.plaindatetime.prototype.daysinyear
+description: >
+  Calling the method on an instance constructed with a builtin calendar causes
+  no observable lookups or calls to calendar methods.
+includes: [temporalHelpers.js]
+features: [Temporal]
+---*/
+
+const daysInYearOriginal = Object.getOwnPropertyDescriptor(Temporal.Calendar.prototype, "daysInYear");
+Object.defineProperty(Temporal.Calendar.prototype, "daysInYear", {
+  configurable: true,
+  enumerable: false,
+  get() {
+    TemporalHelpers.assertUnreachable("daysInYear should not be looked up");
+  },
+});
+
+const instance = new Temporal.PlainDateTime(2000, 5, 2, 12, 34, 56, 987, 654, 321, "iso8601");
+instance.daysInYear;
+
+Object.defineProperty(Temporal.Calendar.prototype, "daysInYear", daysInYearOriginal);
+
+reportCompare(0, 0);