[Fix] IteratorZip AO: allow an empty list of iterators

 - also, add tests for `zipKeyed`

.eslintrc

@@ -54,6 +54,7 @@
 				"ToBoolean",
 				"ToIntegerOrInfinity",
 				"ToNumber",
+				"ToPropertyDescriptor",
 				"Type",
 			],
 		}],

Iterator.zipKeyed/implementation.js

@@ -13,6 +13,7 @@ var IsDataDescriptor = require('es-abstract/2024/IsDataDescriptor');
 var IteratorZip = require('../aos/IteratorZip');
 var OrdinaryObjectCreate = require('es-abstract/2024/OrdinaryObjectCreate');
 var ThrowCompletion = require('es-abstract/2024/ThrowCompletion');
+var ToPropertyDescriptor = require('es-abstract/2024/ToPropertyDescriptor');
 var Type = require('es-abstract/2024/Type');
 
 var forEach = require('es-abstract/helpers/forEach');
@@ -43,10 +44,10 @@ module.exports = function zipKeyed(iterables) {
 
 	var paddingOption; // step 6
 
-	if (mode === 'longest') {
-		paddingOption = Get(options, 'padding'); // step 7
+	if (mode === 'longest') { // step 7
+		paddingOption = Get(options, 'padding'); // step 7.a
 		if (typeof paddingOption !== 'undefined' && Type(paddingOption) !== 'Object') {
-			throw new $TypeError('`padding` option must be an Object'); // step 7.1
+			throw new $TypeError('`padding` option must be an Object'); // step 7.b
 		}
 	}
 
@@ -61,7 +62,7 @@ module.exports = function zipKeyed(iterables) {
 	forEach(allKeys, function (key) { // step 12
 		var desc;
 		try {
-			desc = gOPD(iterables, key); // step 12.a
+			desc = ToPropertyDescriptor(gOPD(iterables, key)); // step 12.a
 		} catch (e) {
 			IfAbruptCloseIterators(ThrowCompletion(e), iters); // step 12.b
 		}
@@ -92,8 +93,7 @@ module.exports = function zipKeyed(iterables) {
 				try {
 					iter = GetIteratorFlattenable(value, 'REJECT-STRINGS'); // step 12.c.iv.2
 				} catch (e) {
-					// step 12.c.iv.3
-					// 3. IfAbruptCloseIterators(e, iters).
+					IfAbruptCloseIterators(ThrowCompletion(e), iters); // step 12.c.iv.3
 				}
 				iters[iters.length] = iter; // step 12.c.iv.4
 			}

aos/IteratorZip.js

@@ -12,7 +12,7 @@ var ThrowCompletion = require('es-abstract/2024/ThrowCompletion');
 var isAbstractClosure = require('es-abstract/helpers/isAbstractClosure');
 var IsArray = require('es-abstract/helpers/IsArray');
 var isIteratorRecord = require('es-abstract/helpers/records/iterator-record');
-var some = require('es-abstract/helpers/some');
+var every = require('es-abstract/helpers/every');
 
 var callBound = require('call-bind/callBound');
 
@@ -27,7 +27,7 @@ var SLOT = require('internal-slot');
 // https://tc39.es/proposal-joint-iteration/#sec-IteratorZip
 
 module.exports = function IteratorZip(iters, mode, padding, finishResults) {
-	if (!IsArray(iters) || !some(iters, isIteratorRecord)) {
+	if (!IsArray(iters) || !every(iters, isIteratorRecord)) {
 		throw new $TypeError('`iters` must be a List of IteratorRecords');
 	}
 

test/Iterator.zipKeyed.js

@@ -0,0 +1,151 @@
+'use strict';
+
+var defineProperties = require('define-properties');
+var test = require('tape');
+var callBind = require('call-bind');
+var functionsHaveNames = require('functions-have-names')();
+var forEach = require('for-each');
+var debug = require('object-inspect');
+var v = require('es-value-fixtures');
+var hasSymbols = require('has-symbols/shams')();
+var mockProperty = require('mock-property');
+
+var index = require('../Iterator.zipKeyed');
+var impl = require('../Iterator.zipKeyed/implementation');
+var from = require('../Iterator.from/polyfill')();
+
+var testIterator = require('./helpers/testIterator');
+
+var isEnumerable = Object.prototype.propertyIsEnumerable;
+
+module.exports = {
+	tests: function (zipKeyed, name, t) {
+		t['throws'](
+			function () { return new zipKeyed(); }, // eslint-disable-line new-cap
+			TypeError,
+			'`' + name + '` itself is not a constructor'
+		);
+		t['throws'](
+			function () { return new zipKeyed({}); }, // eslint-disable-line new-cap
+			TypeError,
+			'`' + name + '` itself is not a constructor, with an argument'
+		);
+
+		forEach(v.primitives, function (primitive) {
+			t['throws'](
+				function () { zipKeyed(primitive); },
+				TypeError,
+				debug(primitive) + ' is not an Object'
+			);
+			if (primitive != null) {
+				t['throws'](
+					function () { zipKeyed({ a: primitive }); },
+					TypeError,
+					'key "a" on iterables object is ' + debug(primitive) + ' which is not an iterable Object'
+				);
+			}
+		});
+
+		forEach(v.objects, function (nonIterator) {
+			t.doesNotThrow(function () { zipKeyed({ a: nonIterator }); }, 'does not throw until `.next()`');
+
+			t['throws'](
+				function () { zipKeyed({ a: nonIterator }).next(); },
+				TypeError,
+				'key "a" on iterables object is ' + debug(nonIterator) + ' which is not an iterable Object'
+			);
+		});
+
+		t.test('actual iteration', { skip: !hasSymbols }, function (st) {
+			forEach(v.nonFunctions, function (nonFunction) {
+				if (nonFunction != null) {
+					var badIterable = {};
+					badIterable[Symbol.iterator] = nonFunction;
+					st['throws'](
+						function () { zipKeyed({ a: [], b: badIterable, c: [] }).next(); },
+						TypeError,
+						'key "b" on iterables object is ' + debug(badIterable) + ' is not a function'
+					);
+				}
+			});
+
+			forEach(v.strings, function (string) {
+				st['throws'](
+					function () { zipKeyed({ a: string }); },
+					TypeError,
+					'key "a" on iterables object is an iterable primitive, but non-objects are not considered iterable'
+				);
+			});
+
+			st.test('real iterators', { skip: !hasSymbols }, function (s2t) {
+				var iter = [['a', 1], ['b', 2]][Symbol.iterator]();
+				var iterator = zipKeyed({ a: iter, b: ['a', 3], c: ['b', 4] });
+
+				testIterator(
+					iterator,
+					[
+						{ __proto__: null, a: ['a', 1], b: 'a', c: 'b' },
+						{ __proto__: null, a: ['b', 2], b: 3, c: 4 }
+					],
+					s2t,
+					'array iterator + array yields combined results'
+				);
+
+				s2t.end();
+			});
+
+			st.test('observability in a replaced String iterator', function (s2t) {
+				var originalStringIterator = String.prototype[Symbol.iterator];
+				var observedType;
+				s2t.teardown(mockProperty(String.prototype, Symbol.iterator, {
+					get: function () {
+						'use strict'; // eslint-disable-line strict, lines-around-directive
+
+						observedType = typeof this;
+						return originalStringIterator;
+					}
+				}));
+
+				zipKeyed([from('')]);
+				s2t.equal(observedType, 'string', 'string primitive -> primitive receiver in Symbol.iterator getter');
+				zipKeyed([from(Object(''))]);
+				s2t.equal(observedType, 'object', 'boxed string -> boxed string in Symbol.iterator getter');
+
+				s2t.end();
+			});
+
+			st.end();
+		});
+	},
+	index: function () {
+		test('Iterator.zipKeyed: index', function (t) {
+			module.exports.tests(index, 'Iterator.zipKeyed', t);
+
+			t.end();
+		});
+	},
+	implementation: function () {
+		test('Iterator.zipKeyed: implementation', function (t) {
+			module.exports.tests(impl, 'Iterator.zipKeyed', t);
+
+			t.end();
+		});
+	},
+	shimmed: function () {
+		test('Iterator.zipKeyed: shimmed', function (t) {
+			t.test('Function name', { skip: !functionsHaveNames }, function (st) {
+				st.equal(Iterator.zipKeyed.name, 'zipKeyed', 'Iterator.zipKeyed has name "zipKeyed"');
+				st.end();
+			});
+
+			t.test('enumerability', { skip: !defineProperties.supportsDescriptors }, function (et) {
+				et.equal(false, isEnumerable.call(Iterator, 'zipKeyed'), 'Iterator.zipKeyed is not enumerable');
+				et.end();
+			});
+
+			module.exports.tests(callBind(Iterator.zipKeyed, Iterator), 'Iterator.zipKeyed', t);
+
+			t.end();
+		});
+	}
+};