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diff --git a/js/src/tests/test262/built-ins/Date/prototype/setMonth/arg-coercion-order.js b/js/src/tests/test262/built-ins/Date/prototype/setMonth/arg-coercion-order.js
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+++ b/js/src/tests/test262/built-ins/Date/prototype/setMonth/arg-coercion-order.js
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+// Copyright (C) 2021 Kevin Gibbons. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-date.prototype.setmonth
+description: Order of coercion of provided argument vs NaN check
+info: |
+  1. Let t be ? thisTimeValue(this value).
+  2. Let m be ? ToNumber(month).
+  3. If date is present, let dt be ? ToNumber(date).
+  4. If t is NaN, return NaN.
+  5. Set t to LocalTime(t).
+  6. If date is not present, let dt be DateFromTime(t).
+  7. Let newDate be MakeDate(MakeDay(YearFromTime(t), m, dt), TimeWithinDay(t)).
+  8. Let u be TimeClip(UTC(newDate)).
+  9. Set the [[DateValue]] internal slot of this Date object to u.
+  10. Return u.
+includes: [compareArray.js]
+---*/
+
+var date = new Date(NaN);
+var effects = [];
+var argMonth = {
+  valueOf: function() {
+    effects.push('valueOf month');
+    return 0;
+  }
+};
+var argDate = {
+  valueOf: function() {
+    effects.push('valueOf date');
+    return 0;
+  }
+};
+
+var returnValue = date.setMonth(argMonth, argDate);
+
+var expectedEffects = ['valueOf month', 'valueOf date'];
+
+assert.compareArray(effects, expectedEffects);
+assert.sameValue(returnValue, NaN, 'argument is ignored when `this` is an invalid date');
+assert.sameValue(date.getTime(), NaN, 'argument is ignored when `this` is an invalid date');
+
+reportCompare(0, 0);