Bug 1147371: Implement IteratorClose for for-of

Issue #74

1 files changed, 102 insertions, 0 deletions

diff --git a/js/src/tests/ecma_6/Statements/for-of-iterator-close.js b/js/src/tests/ecma_6/Statements/for-of-iterator-close.js
new file mode 100644
index 000000000..b28895d8f
--- /dev/null
+++ b/js/src/tests/ecma_6/Statements/for-of-iterator-close.js
@@ -0,0 +1,102 @@
+// Tests that IteratorReturn is called when a for-of loop has an abrupt
+// completion value during non-iterator code.
+
+function test() {
+    var returnCalled = 0;
+    var returnCalledExpected = 0;
+    var iterable = {};
+    iterable[Symbol.iterator] = makeIterator({
+        ret: function() {
+            returnCalled++;
+            return {};
+        }
+    });
+
+    // break calls iter.return
+    for (var x of iterable)
+        break;
+    assertEq(returnCalled, ++returnCalledExpected);
+
+    // throw in body calls iter.return
+    assertThrowsValue(function() {
+        for (var x of iterable)
+            throw "in body";
+    }, "in body");
+    assertEq(returnCalled, ++returnCalledExpected);
+
+    // throw in lhs ref calls iter.return
+    function throwlhs() {
+        throw "in lhs";
+    }
+    assertThrowsValue(function() {
+        for ((throwlhs()) of iterable)
+            continue;
+    }, "in lhs");
+    assertEq(returnCalled, ++returnCalledExpected);
+
+    // throw in iter.return doesn't re-call iter.return
+    iterable[Symbol.iterator] = makeIterator({
+        ret: function() {
+            returnCalled++;
+            throw "in iter.return";
+        }
+    });
+    assertThrowsValue(function() {
+        for (var x of iterable)
+            break;
+    }, "in iter.return");
+    assertEq(returnCalled, ++returnCalledExpected);
+
+    // throw in iter.next doesn't call IteratorClose
+    iterable[Symbol.iterator] = makeIterator({
+        next: function() {
+            throw "in next";
+        }
+    });
+    assertThrowsValue(function() {
+        for (var x of iterable)
+            break;
+    }, "in next");
+    assertEq(returnCalled, returnCalledExpected);
+
+    // "return" must return an Object.
+    iterable[Symbol.iterator] = makeIterator({
+        ret: function() {
+            returnCalled++;
+            return 42;
+        }
+    });
+    assertThrowsInstanceOf(function() {
+        for (var x of iterable)
+            break;
+    }, TypeError);
+    assertEq(returnCalled, ++returnCalledExpected);
+
+    // continue doesn't call iter.return for the loop it's continuing
+    var i = 0;
+    iterable[Symbol.iterator] = makeIterator({
+        next: function() {
+            return { done: i++ > 5 };
+        },
+        ret: function() {
+            returnCalled++;
+            return {};
+        }
+    });
+    for (var x of iterable)
+        continue;
+    assertEq(returnCalled, returnCalledExpected);
+
+    // continue does call iter.return for loops it skips
+    i = 0;
+    L: do {
+        for (var x of iterable)
+            continue L;
+    } while (false);
+    assertEq(returnCalled, ++returnCalledExpected);
+}
+
+test();
+
+if (typeof reportCompare === "function")
+    reportCompare(0, 0);