Improves iterator tests for Promise.any, Promise.allSettled, and …

…`AggregateError` polyfills
JakeChampion · Nov 23, 2021 · 999dbce · 999dbce
1 parent 843c4a0
commit 999dbce
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Showing 3 changed files with 99 additions and 51 deletions.
diff --git a/polyfills/AggregateError/tests.js b/polyfills/AggregateError/tests.js
@@ -1,6 +1,22 @@
 
 /* globals proclaim, AggregateError */
 
+function makeArrayIterator (array) {
+	var i = 0;
+	var iterator = {};
+	// polyfill for `Symbol.iterator` has been provided as part of `IterableToList`
+	iterator[self.Symbol.iterator] = function () {
+		return {
+			next: function() {
+				return i >= array.length
+					? { done: true }
+					: { value: array[i++] };
+			}
+		};
+	};
+	return iterator;
+}
+
 it('is a function', function () {
 	proclaim.isFunction(AggregateError);
 });
@@ -29,15 +45,14 @@ describe('AggregateError', function () {
 		proclaim.deepStrictEqual(aggregateError.errors, errors);
 	});
 
-	if ('Symbol' in self && 'iterator' in self.Symbol && !!Array.prototype[self.Symbol.iterator]) {
-		it("constructs an AggregateError when passed an iterator", function () {
-			var errors = [new Error('x'), new Error('y')];
-			var aggregateError = new AggregateError(errors[self.Symbol.iterator]());
-			proclaim.equal(aggregateError.message, '');
-			proclaim.notEqual(aggregateError.errors, errors);
-			proclaim.deepStrictEqual(aggregateError.errors, errors);
-		});
-	}
+	it("constructs an AggregateError when passed an iterator", function () {
+		var errors = [new Error('x'), new Error('y')];
+		var iterator = makeArrayIterator(errors);
+		var aggregateError = new AggregateError(iterator);
+		proclaim.equal(aggregateError.message, '');
+		proclaim.notEqual(aggregateError.errors, errors);
+		proclaim.deepStrictEqual(aggregateError.errors, errors);
+	});
 
 	it("throws an error for input that is not iterable", function () {
 		proclaim['throws'](function () {

diff --git a/polyfills/Promise/allSettled/tests.js b/polyfills/Promise/allSettled/tests.js
@@ -1,6 +1,22 @@
 
 /* globals proclaim, Promise */
 
+function makeArrayIterator (array) {
+	var i = 0;
+	var iterator = {};
+	// polyfill for `Symbol.iterator` has been provided as part of `IterableToList`
+	iterator[self.Symbol.iterator] = function () {
+		return {
+			next: function() {
+				return i >= array.length
+					? { done: true }
+					: { value: array[i++] };
+			}
+		};
+	};
+	return iterator;
+}
+
 it('is a function', function () {
 	proclaim.isFunction(Promise.allSettled);
 });
@@ -34,27 +50,26 @@ describe('allSettled', function () {
 		});
 	});
 
-	if ('Symbol' in self && 'iterator' in self.Symbol && !!Array.prototype[self.Symbol.iterator]) {
-		it("resolves to an array of results when passed an iterator", function () {
-			var promises = [1, Promise.resolve(2), Promise.reject(3)];
-			return Promise.allSettled(promises[self.Symbol.iterator]()).then(function (results) {
-				proclaim.deepStrictEqual(results, [
-					{
-						status: 'fulfilled',
-						value: 1
-					},
-					{
-						status: 'fulfilled',
-						value: 2
-					},
-					{
-						status: 'rejected',
-						reason: 3
-					}
-				]);
-			});
+	it("resolves to an array of results when passed an iterator", function () {
+		var promises = [1, Promise.resolve(2), Promise.reject(3)];
+		var iterator = makeArrayIterator(promises);
+		return Promise.allSettled(iterator).then(function (results) {
+			proclaim.deepStrictEqual(results, [
+				{
+					status: 'fulfilled',
+					value: 1
+				},
+				{
+					status: 'fulfilled',
+					value: 2
+				},
+				{
+					status: 'rejected',
+					reason: 3
+				}
+			]);
 		});
-	}
+	});
 
 	it("rejects with a TypeError for input that is not iterable", function () {
 		return Promise.allSettled(0)['catch'](function (err) {

diff --git a/polyfills/Promise/any/tests.js b/polyfills/Promise/any/tests.js
@@ -1,6 +1,22 @@
 
 /* globals proclaim, Promise */
 
+function makeArrayIterator (array) {
+	var i = 0;
+	var iterator = {};
+	// polyfill for `Symbol.iterator` has been provided as part of `IterableToList`
+	iterator[self.Symbol.iterator] = function () {
+		return {
+			next: function() {
+				return i >= array.length
+					? { done: true }
+					: { value: array[i++] };
+			}
+		};
+	};
+	return iterator;
+}
+
 it('is a function', function () {
 	proclaim.isFunction(Promise.any);
 });
@@ -40,33 +56,35 @@ describe('any', function () {
 		});
 	});
 
-	if ('Symbol' in self && 'iterator' in self.Symbol && !!Array.prototype[self.Symbol.iterator]) {
-		it("resolves to the first fulfilled promise when passed an iterator", function () {
-			var promises = [Promise.reject(1), Promise.resolve(2), 3];
-			return Promise.any(promises[self.Symbol.iterator]()).then(function (result) {
-				proclaim.strictEqual(result, 2);
-			});
+	it("resolves to the first fulfilled promise when passed an iterator", function () {
+		var promises = [Promise.reject(1), Promise.resolve(2), 3];
+		var iterator = makeArrayIterator(promises);
+		return Promise.any(iterator).then(function (result) {
+			proclaim.strictEqual(result, 2);
 		});
+	});
 
-		it("rejects with an AggregateError when passed an iterator containing rejected promises", function () {
-			var promises = [Promise.reject(1)];
-			return Promise.any(promises[self.Symbol.iterator]())['catch'](function (err) {
-				return err;
-			}).then(function (err) {
-				proclaim.equal(err.name, 'AggregateError');
-				proclaim.deepStrictEqual(err.errors, [1]);
-			});
+	it("rejects with an AggregateError when passed an iterator containing rejected promises", function () {
+		var promises = [Promise.reject(1)];
+		var iterator = makeArrayIterator(promises);
+		return Promise.any(iterator)['catch'](function (err) {
+			return err;
+		}).then(function (err) {
+			proclaim.equal(err.name, 'AggregateError');
+			proclaim.deepStrictEqual(err.errors, [1]);
 		});
+	});
 
-		it("rejects with an AggregateError when passed an empty iterable", function () {
-			return Promise.any([][self.Symbol.iterator]())['catch'](function (err) {
-				return err;
-			}).then(function (err) {
-				proclaim.equal(err.name, 'AggregateError');
-				proclaim.deepStrictEqual(err.errors, []);
-			});
+	it("rejects with an AggregateError when passed an empty iterable", function () {
+		var promises = [];
+		var iterator = makeArrayIterator(promises);
+		return Promise.any(iterator)['catch'](function (err) {
+			return err;
+		}).then(function (err) {
+			proclaim.equal(err.name, 'AggregateError');
+			proclaim.deepStrictEqual(err.errors, []);
 		});
-	}
+	});
 
 	it("rejects with a TypeError for input that is not iterable", function () {
 		return Promise.any(0)['catch'](function (err) {