fix iterator closing in AsyncIterator.prototype.map polyfill

CHANGELOG.md

@@ -51,7 +51,7 @@
 - Fixed `%AsyncFromSyncIteratorPrototype%` to make it a little stricter
 - Fixed counter in some cases of some `AsyncIterator` methods
 - Fixed order of async iterators closing
-- Fixed iterator closing in `AsyncIterator.prototype.flatMap` polyfill
+- Fixed iterator closing in `AsyncIterator.prototype.{ map, flatMap }` polyfills
 - Fixed iterator closing in `AsyncIterator.prototype.take` polyfill with `return: null`
 - Fixed validation `return()` result as object in `AsyncIterator.prototype.take` polyfill
 - Fixed a lack of error in `structuredClone` polyfill on attempt to transfer multiple objects, some of which are non-transferable

packages/core-js/internals/async-iterator-map.js

@@ -23,26 +23,28 @@ var AsyncIteratorProxy = createAsyncIteratorProxy(function (Promise) {
       closeAsyncIteration(iterator, doneAndReject, error, doneAndReject);
     };
 
-    Promise.resolve(anObject(call(state.next, iterator))).then(function (step) {
-      try {
-        if (anObject(step).done) {
-          state.done = true;
-          resolve(createIterResultObject(undefined, true));
-        } else {
-          var value = step.value;
-          try {
-            var result = mapper(value, state.counter++);
+    try {
+      Promise.resolve(anObject(call(state.next, iterator))).then(function (step) {
+        try {
+          if (anObject(step).done) {
+            state.done = true;
+            resolve(createIterResultObject(undefined, true));
+          } else {
+            var value = step.value;
+            try {
+              var result = mapper(value, state.counter++);
 
-            var handler = function (mapped) {
-              resolve(createIterResultObject(mapped, false));
-            };
+              var handler = function (mapped) {
+                resolve(createIterResultObject(mapped, false));
+              };
 
-            if (isObject(result)) Promise.resolve(result).then(handler, ifAbruptCloseAsyncIterator);
-            else handler(result);
-          } catch (error2) { ifAbruptCloseAsyncIterator(error2); }
-        }
-      } catch (error) { doneAndReject(error); }
-    }, doneAndReject);
+              if (isObject(result)) Promise.resolve(result).then(handler, ifAbruptCloseAsyncIterator);
+              else handler(result);
+            } catch (error2) { ifAbruptCloseAsyncIterator(error2); }
+          }
+        } catch (error) { doneAndReject(error); }
+      }, doneAndReject);
+    } catch (error) { doneAndReject(error); }
   });
 });
 

tests/unit-global/esnext.async-iterator.map.js

@@ -41,5 +41,21 @@ QUnit.test('AsyncIterator#map', assert => {
     assert.avoid();
   }, error => {
     assert.same(error, 42, 'rejection on a callback error');
+  }).then(() => {
+    let calls = 0;
+    const iterator = createIterator([1, 2, 3], {
+      next() { calls++; throw 43; },
+    });
+    const mapped = map.call(iterator, it => it);
+    return mapped.next().then(() => {
+      assert.avoid();
+    }, error => {
+      assert.same(error, 43, 'rejection on next() sync error');
+      assert.same(calls, 1, 'next() called once');
+      return mapped.next();
+    }).then(result => {
+      assert.true(result.done, 'done after next() sync error');
+      assert.same(calls, 1, 'next() not called again after sync error');
+    });
   });
 });

tests/unit-pure/esnext.async-iterator.map.js

@@ -41,5 +41,21 @@ QUnit.test('AsyncIterator#map', assert => {
     assert.avoid();
   }, error => {
     assert.same(error, 42, 'rejection on a callback error');
+  }).then(() => {
+    let calls = 0;
+    const iterator = createIterator([1, 2, 3], {
+      next() { calls++; throw 43; },
+    });
+    const mapped = map.call(iterator, it => it);
+    return mapped.next().then(() => {
+      assert.avoid();
+    }, error => {
+      assert.same(error, 43, 'rejection on next() sync error');
+      assert.same(calls, 1, 'next() called once');
+      return mapped.next();
+    }).then(result => {
+      assert.true(result.done, 'done after next() sync error');
+      assert.same(calls, 1, 'next() not called again after sync error');
+    });
   });
 });