Fix yield * of falsy values (#711)

facebook · Dec 14, 2023 · 50ed6aa · 50ed6aa
1 parent 7c16d9b
commit 50ed6aa
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Showing 2 changed files with 12 additions and 1 deletion.
diff --git a/packages/runtime/runtime.js b/packages/runtime/runtime.js
@@ -487,7 +487,7 @@ var runtime = (function (exports) {
   };
 
   function values(iterable) {
-    if (iterable || iterable === "") {
+    if (iterable != null) {
       var iteratorMethod = iterable[iteratorSymbol];
       if (iteratorMethod) {
         return iteratorMethod.call(iterable);

diff --git a/test/tests.es6.js b/test/tests.es6.js
@@ -1537,6 +1537,17 @@ describe("delegated yield", function() {
       it.next();
     }, TypeError);
   });
+
+  it("should work with falsy values", function () {
+    try {
+      Boolean.prototype[Symbol.iterator] = function* () { yield "Hello" };
+      function* gen() { yield* false; };
+
+      check(gen(), ["Hello"]);
+    } finally {
+      delete Boolean.prototype[Symbol.iterator];
+    }
+  });
 });
 
 (fullCompatibility