Temporal: Tests for removal of relativeTo from Duration.p.add

See tc39/proposal-temporal#2825.

Various edits to existing tests so that they make more sense with the
removal of relativeTo.

New test specifically testing that calendar units cannot be added
directly.

test/built-ins/Temporal/Duration/prototype/add/balance-negative-result.js

@@ -11,5 +11,5 @@ features: [Temporal]
 const duration1 = new Temporal.Duration(0, 0, 0, 0, -60);
 const duration2 = new Temporal.Duration(0, 0, 0, -1);
 
-const resultNotRelative = duration1.add(duration2);
-TemporalHelpers.assertDuration(resultNotRelative, 0, 0, 0, -3, -12, 0, 0, 0, 0, 0);
+const result = duration1.add(duration2);
+TemporalHelpers.assertDuration(result, 0, 0, 0, -3, -12, 0, 0, 0, 0, 0);

test/built-ins/Temporal/Duration/prototype/add/no-calendar-units.js

@@ -0,0 +1,35 @@
+// Copyright (C) 2024 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.duration.prototype.add
+description: >
+  Throws if either the receiver or the argument is a duration with nonzero
+  calendar units
+features: [Temporal]
+---*/
+
+const blank = new Temporal.Duration();
+
+const withYears = new Temporal.Duration(1);
+assert.throws(RangeError, () => withYears.add(blank), "should not add to receiver with years");
+
+const withMonths = new Temporal.Duration(0, 1);
+assert.throws(RangeError, () => withMonths.add(blank), "should not add to receiver with months");
+
+const withWeeks = new Temporal.Duration(0, 0, 1);
+assert.throws(RangeError, () => withWeeks.add(blank), "should not add to receiver with weeks");
+
+const ok = new Temporal.Duration(0, 0, 0, 1);
+
+assert.throws(RangeError, () => ok.add(withYears), "should not add duration with years");
+assert.throws(RangeError, () => ok.add(withMonths), "should not add duration with months");
+assert.throws(RangeError, () => ok.add(withWeeks), "should not add duration with weeks");
+
+assert.throws(RangeError, () => ok.add({ years: 1 }), "should not add property bag with years");
+assert.throws(RangeError, () => ok.add({ months: 1 }), "should not add property bag with months");
+assert.throws(RangeError, () => ok.add({ weeks: 1 }), "should not add property bag with weeks");
+
+assert.throws(RangeError, () => ok.add('P1Y'), "should not add string with years");
+assert.throws(RangeError, () => ok.add('P1M'), "should not add string with months");
+assert.throws(RangeError, () => ok.add('P1W'), "should not add string with weeks");

test/built-ins/Temporal/Duration/prototype/add/order-of-operations.js

@@ -43,7 +43,7 @@ const expected = [
 ];
 const actual = [];
 
-const simpleFields = TemporalHelpers.propertyBagObserver(actual, {
+const fields = TemporalHelpers.propertyBagObserver(actual, {
   years: 0,
   months: 0,
   weeks: 0,
@@ -57,7 +57,7 @@ const simpleFields = TemporalHelpers.propertyBagObserver(actual, {
 }, "fields");
 
 // basic order of observable operations, without any calendar units:
-const simpleInstance = new Temporal.Duration(0, 0, 0, 1, 1, 1, 1, 1, 1, 1);
-simpleInstance.add(simpleFields);
+const instance = new Temporal.Duration(0, 0, 0, 1, 1, 1, 1, 1, 1, 1);
+instance.add(fields);
 assert.compareArray(actual, expected, "order of operations");
 actual.splice(0); // clear