1 files changed, 35 insertions, 0 deletions
diff --git a/js/src/tests/test262/built-ins/Temporal/Calendar/prototype/mergeFields/arguments-empty-object.js b/js/src/tests/test262/built-ins/Temporal/Calendar/prototype/mergeFields/arguments-empty-object.js
new file mode 100644
index 0000000000..a5d437c195
--- /dev/null
+++ b/js/src/tests/test262/built-ins/Temporal/Calendar/prototype/mergeFields/arguments-empty-object.js
@@ -0,0 +1,35 @@
+// |reftest| skip-if(!this.hasOwnProperty('Temporal')) -- Temporal is not enabled unconditionally
+// Copyright (C) 2021 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.calendar.prototype.mergefields
+description: Either argument being an empty object should result in a copy of the other object
+includes: [compareArray.js]
+features: [Temporal]
+---*/
+
+const calendar = new Temporal.Calendar("iso8601");
+
+let calls = 0;
+const yearObserver = {
+  get year() {
+    calls++;
+    return 2021;
+  }
+};
+
+const result1 = calendar.mergeFields(yearObserver, {});
+assert.sameValue(calls, 1, "property copied");
+assert.compareArray(Object.keys(result1), ["year"]);
+assert.sameValue(result1.year, 2021);
+assert.sameValue(calls, 1, "result has a data property");
+
+calls = 0;
+const result2 = calendar.mergeFields({}, yearObserver);
+assert.sameValue(calls, 1, "property copied");
+assert.compareArray(Object.keys(result2), ["year"]);
+assert.sameValue(result2.year, 2021);
+assert.sameValue(calls, 1, "result has a data property");
+
+reportCompare(0, 0);