Merge remote-tracking branch 'janek/js_IteratorClose_1'

8 files changed, 567 insertions, 24 deletions

diff --git a/js/src/tests/ecma_6/Destructuring/array-iterator-close.js b/js/src/tests/ecma_6/Destructuring/array-iterator-close.js
new file mode 100644
index 000000000..ed35135db
--- /dev/null
+++ b/js/src/tests/ecma_6/Destructuring/array-iterator-close.js
@@ -0,0 +1,93 @@
+// Tests that IteratorClose is called in array destructuring patterns.
+
+function test() {
+    var returnCalled = 0;
+    var returnCalledExpected = 0;
+    var iterable = {};
+
+    // empty [] calls IteratorClose regardless of "done" on the result.
+    iterable[Symbol.iterator] = makeIterator({
+        next: function() {
+            return { done: true };
+        },
+        ret: function() {
+            returnCalled++;
+            return {};
+        }
+    });
+    var [] = iterable;
+    assertEq(returnCalled, ++returnCalledExpected);
+
+    iterable[Symbol.iterator] = makeIterator({
+        ret: function() {
+            returnCalled++;
+            return {};
+        }
+    });
+    var [] = iterable;
+    assertEq(returnCalled, ++returnCalledExpected);
+
+    // Non-empty destructuring calls IteratorClose if iterator is not done by
+    // the end of destructuring.
+    var [a,b] = iterable;
+    assertEq(returnCalled, ++returnCalledExpected);
+    var [c,] = iterable;
+    assertEq(returnCalled, ++returnCalledExpected);
+
+    // throw in lhs ref calls IteratorClose
+    function throwlhs() {
+        throw "in lhs";
+    }
+    assertThrowsValue(function() {
+        0, [...{}[throwlhs()]] = iterable;
+    }, "in lhs");
+    assertEq(returnCalled, ++returnCalledExpected);
+
+    // throw in lhs ref calls IteratorClose with falsy "done".
+    iterable[Symbol.iterator] = makeIterator({
+        next: function() {
+            // "done" is undefined.
+            return {};
+        },
+        ret: function() {
+            returnCalled++;
+            return {};
+        }
+    });
+    assertThrowsValue(function() {
+        0, [...{}[throwlhs()]] = iterable;
+    }, "in lhs");
+    assertEq(returnCalled, ++returnCalledExpected);
+
+    // throw in iter.next doesn't call IteratorClose
+    iterable[Symbol.iterator] = makeIterator({
+        next: function() {
+            throw "in next";
+        },
+        ret: function() {
+            returnCalled++;
+            return {};
+        }
+    });
+    assertThrowsValue(function() {
+        var [d] = iterable;
+    }, "in next");
+    assertEq(returnCalled, returnCalledExpected);
+
+    // "return" must return an Object.
+    iterable[Symbol.iterator] = makeIterator({
+        ret: function() {
+            returnCalled++;
+            return 42;
+        }
+    });
+    assertThrowsInstanceOf(function() {
+        var [] = iterable;
+    }, TypeError);
+    assertEq(returnCalled, ++returnCalledExpected);
+}
+
+test();
+
+if (typeof reportCompare === "function")
+    reportCompare(0, 0);
diff --git a/js/src/tests/ecma_6/Generators/delegating-yield-2.js b/js/src/tests/ecma_6/Generators/delegating-yield-2.js
index 918fb33e1..34cb3f4a9 100644
--- a/js/src/tests/ecma_6/Generators/delegating-yield-2.js
+++ b/js/src/tests/ecma_6/Generators/delegating-yield-2.js
@@ -25,8 +25,8 @@ assertThrowsValue(function () { outer.throw(42) }, 42);
 inner = g1();
 outer = delegate(inner);
 assertIteratorNext(outer, 1);
-inner.throw = function(e) { return e*2; };
-assertEq(84, outer.throw(42));
+inner.throw = function(e) { return { value: e*2 }; };
+assertEq(84, outer.throw(42).value);
 assertIteratorDone(outer, undefined);
 
 // Monkeypatching inner.next.
@@ -41,7 +41,9 @@ outer = delegate(inner);
 assertIteratorNext(outer, 1);
 delete GeneratorObjectPrototype.throw;
 var outer_throw_42 = GeneratorObjectPrototype_throw.bind(outer, 42);
-assertThrowsValue(outer_throw_42, 42);
+// yield* protocol violation: no 'throw' method
+assertThrowsInstanceOf(outer_throw_42, TypeError);
+// Now done, so just throws.
 assertThrowsValue(outer_throw_42, 42);
 
 // Monkeypunch a different throw handler.
@@ -49,11 +51,11 @@ inner = g2();
 outer = delegate(inner);
 outer_throw_42 = GeneratorObjectPrototype_throw.bind(outer, 42);
 assertIteratorNext(outer, 1);
-GeneratorObjectPrototype.throw = function(e) { return e*2; }
-assertEq(84, outer_throw_42());
-assertEq(84, outer_throw_42());
+GeneratorObjectPrototype.throw = function(e) { return { value: e*2 }; }
+assertEq(84, outer_throw_42().value);
+assertEq(84, outer_throw_42().value);
 // This continues indefinitely.
-assertEq(84, outer_throw_42());
+assertEq(84, outer_throw_42().value);
 assertIteratorDone(outer, undefined);
 
 // The same, but restoring the original pre-monkey throw.
@@ -61,8 +63,8 @@ inner = g2();
 outer = delegate(inner);
 outer_throw_42 = GeneratorObjectPrototype_throw.bind(outer, 42);
 assertIteratorNext(outer, 1);
-assertEq(84, outer_throw_42());
-assertEq(84, outer_throw_42());
+assertEq(84, outer_throw_42().value);
+assertEq(84, outer_throw_42().value);
 GeneratorObjectPrototype.throw = GeneratorObjectPrototype_throw;
 assertIteratorResult(outer_throw_42(), 42, false);
 assertIteratorDone(outer, undefined);
diff --git a/js/src/tests/ecma_6/Generators/yield-iterator-close.js b/js/src/tests/ecma_6/Generators/yield-iterator-close.js
new file mode 100644
index 000000000..970ad494d
--- /dev/null
+++ b/js/src/tests/ecma_6/Generators/yield-iterator-close.js
@@ -0,0 +1,58 @@
+// Test that IteratorClose is called when a Generator is abruptly completed by
+// Generator.return.
+
+var returnCalled = 0;
+function* wrapNoThrow() {
+  let iter = {
+    [Symbol.iterator]() {
+      return this;
+    },
+    next() {
+      return { value: 10, done: false };
+    },
+    return() {
+      returnCalled++;
+      return {};
+    }
+  };
+  for (const i of iter) {
+    yield i;
+  }
+}
+
+// Breaking calls Generator.return, which causes the yield above to resume with
+// an abrupt completion of kind "return", which then calls
+// iter.return.
+for (const i of wrapNoThrow()) {
+  break;
+}
+assertEq(returnCalled, 1);
+
+function* wrapThrow() {
+  let iter = {
+    [Symbol.iterator]() {
+      return this;
+    },
+    next() {
+      return { value: 10, done: false };
+    },
+    return() {
+      throw 42;
+    }
+  };
+  for (const i of iter) {
+    yield i;
+  }
+}
+
+// Breaking calls Generator.return, which, like above, calls iter.return. If
+// iter.return throws, since the yield is resuming with an abrupt completion of
+// kind "return", the newly thrown value takes precedence over returning.
+assertThrowsValue(() => {
+  for (const i of wrapThrow()) {
+    break;
+  }
+}, 42);
+
+if (typeof reportCompare === "function")
+  reportCompare(0, 0);
diff --git a/js/src/tests/ecma_6/Generators/yield-star-iterator-close.js b/js/src/tests/ecma_6/Generators/yield-star-iterator-close.js
new file mode 100644
index 000000000..91ad31cb6
--- /dev/null
+++ b/js/src/tests/ecma_6/Generators/yield-star-iterator-close.js
@@ -0,0 +1,153 @@
+// Tests that the "return" method on iterators is called in yield*
+// expressions.
+
+function test() {
+    var returnCalled = 0;
+    var returnCalledExpected = 0;
+    var nextCalled = 0;
+    var nextCalledExpected = 0;
+    var throwCalled = 0;
+    var throwCalledExpected = 0;
+    var iterable = {};
+    iterable[Symbol.iterator] = makeIterator({
+        next: function() {
+            nextCalled++;
+            return { done: false };
+        },
+        ret: function() {
+            returnCalled++;
+            return { done: true, value: "iter.return" };
+        }
+    });
+
+    function* y() {
+        yield* iterable;
+    }
+
+    // G.p.throw on an iterator without "throw" calls IteratorClose.
+    var g1 = y();
+    g1.next();
+    assertThrowsInstanceOf(function() {
+        g1.throw("foo");
+    }, TypeError);
+    assertEq(returnCalled, ++returnCalledExpected);
+    assertEq(nextCalled, ++nextCalledExpected);
+    g1.next();
+    assertEq(nextCalled, nextCalledExpected);
+
+    // G.p.return calls "return", and if the result.done is true, return the
+    // result.
+    var g2 = y();
+    g2.next();
+    var v2 = g2.return("test return");
+    assertEq(v2.done, true);
+    assertEq(v2.value, "iter.return");
+    assertEq(returnCalled, ++returnCalledExpected);
+    assertEq(nextCalled, ++nextCalledExpected);
+    g2.next();
+    assertEq(nextCalled, nextCalledExpected);
+
+    // G.p.return calls "return", and if the result.done is false, continue
+    // yielding.
+    iterable[Symbol.iterator] = makeIterator({
+        next: function() {
+            nextCalled++;
+            return { done: false };
+        },
+        ret: function() {
+            returnCalled++;
+            return { done: false, value: "iter.return" };
+        }
+    });
+    var g3 = y();
+    g3.next();
+    var v3 = g3.return("test return");
+    assertEq(v3.done, false);
+    assertEq(v3.value, "iter.return");
+    assertEq(returnCalled, ++returnCalledExpected);
+    assertEq(nextCalled, ++nextCalledExpected);
+    g3.next();
+    assertEq(nextCalled, ++nextCalledExpected);
+
+    // G.p.return throwing does not re-call iter.return.
+    iterable[Symbol.iterator] = makeIterator({
+        ret: function() {
+            returnCalled++;
+            throw "in iter.return";
+        }
+    });
+    var g4 = y();
+    g4.next();
+    assertThrowsValue(function() {
+        g4.return("in test");
+    }, "in iter.return");
+    assertEq(returnCalled, ++returnCalledExpected);
+
+    // G.p.return expects iter.return to return an Object.
+    iterable[Symbol.iterator] = makeIterator({
+        ret: function() {
+            returnCalled++;
+            return 42;
+        }
+    });
+    var g5 = y();
+    g5.next();
+    assertThrowsInstanceOf(function() {
+        g5.return("foo");
+    }, TypeError);
+    assertEq(returnCalled, ++returnCalledExpected);
+
+    // IteratorClose expects iter.return to return an Object.
+    var g6 = y();
+    g6.next();
+    var exc;
+    try {
+        g6.throw("foo");
+    } catch (e) {
+        exc = e;
+    } finally {
+        assertEq(exc instanceof TypeError, true);
+        // The message test is here because instanceof TypeError doesn't
+        // distinguish the non-Object return TypeError and the
+        // throw-method-is-not-defined iterator protocol error.
+        assertEq(exc.toString().indexOf("non-object") > 0, true);
+    }
+    assertEq(returnCalled, ++returnCalledExpected);
+
+    // G.p.return passes its argument to "return".
+    iterable[Symbol.iterator] = makeIterator({
+        ret: function(x) {
+            assertEq(x, "in test");
+            returnCalled++;
+            return { done: true };
+        }
+    });
+    var g7 = y();
+    g7.next();
+    g7.return("in test");
+    assertEq(returnCalled, ++returnCalledExpected);
+
+    // If a throw method is present, do not call "return".
+    iterable[Symbol.iterator] = makeIterator({
+        throw: function(e) {
+            throwCalled++;
+            throw e;
+        },
+        ret: function(x) {
+            returnCalled++;
+            return { done: true };
+        }
+    });
+    var g8 = y();
+    g8.next();
+    assertThrowsValue(function() {
+        g8.throw("foo");
+    }, "foo");
+    assertEq(throwCalled, ++throwCalledExpected);
+    assertEq(returnCalled, returnCalledExpected);
+}
+
+test();
+
+if (typeof reportCompare === "function")
+    reportCompare(0, 0);
diff --git a/js/src/tests/ecma_6/Statements/for-inof-finally.js b/js/src/tests/ecma_6/Statements/for-inof-finally.js
new file mode 100644
index 000000000..e1f0c77e1
--- /dev/null
+++ b/js/src/tests/ecma_6/Statements/for-inof-finally.js
@@ -0,0 +1,78 @@
+var BUGNUMBER = 1332881;
+var summary =
+  "Leaving for-in and try should handle stack value in correct order";
+
+print(BUGNUMBER + ": " + summary);
+
+var called = 0;
+function reset() {
+  called = 0;
+}
+var obj = {
+  [Symbol.iterator]() {
+    return {
+      next() {
+        return { value: 10, done: false };
+      },
+      return() {
+        called++;
+        return {};
+      }
+    };
+  }
+};
+
+var a = (function () {
+    for (var x in [0]) {
+        try {} finally {
+            return 11;
+        }
+    }
+})();
+assertEq(a, 11);
+
+reset();
+var b = (function () {
+    for (var x of obj) {
+        try {} finally {
+            return 12;
+        }
+    }
+})();
+assertEq(called, 1);
+assertEq(b, 12);
+
+reset();
+var c = (function () {
+    for (var x in [0]) {
+        for (var y of obj) {
+            try {} finally {
+                return 13;
+            }
+        }
+    }
+})();
+assertEq(called, 1);
+assertEq(c, 13);
+
+reset();
+var d = (function () {
+    for (var x in [0]) {
+        for (var y of obj) {
+            try {} finally {
+                for (var z in [0]) {
+                    for (var w of obj) {
+                        try {} finally {
+                            return 14;
+                        }
+                    }
+                }
+            }
+        }
+    }
+})();
+assertEq(called, 2);
+assertEq(d, 14);
+
+if (typeof reportCompare === "function")
+  reportCompare(true, true);
diff --git a/js/src/tests/ecma_6/Statements/for-of-iterator-close-throw.js b/js/src/tests/ecma_6/Statements/for-of-iterator-close-throw.js
new file mode 100644
index 000000000..1974e416b
--- /dev/null
+++ b/js/src/tests/ecma_6/Statements/for-of-iterator-close-throw.js
@@ -0,0 +1,35 @@
+function test() {
+    var returnCalled = 0;
+    var returnCalledExpected = 0;
+    var catchEntered = 0;
+    var finallyEntered = 0;
+    var finallyEnteredExpected = 0;
+    var iterable = {};
+    iterable[Symbol.iterator] = makeIterator({
+        ret: function() {
+            returnCalled++;
+            throw 42;
+        }
+    });
+
+    // inner try cannot catch IteratorClose throwing
+    assertThrowsValue(function() {
+        for (var x of iterable) {
+            try {
+                return;
+            } catch (e) {
+                catchEntered++;
+            } finally {
+                finallyEntered++;
+            }
+        }
+    }, 42);
+    assertEq(returnCalled, ++returnCalledExpected);
+    assertEq(catchEntered, 0);
+    assertEq(finallyEntered, ++finallyEnteredExpected);
+}
+
+test();
+
+if (typeof reportCompare === "function")
+    reportCompare(0, 0);
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);
diff --git a/js/src/tests/ecma_6/shell.js b/js/src/tests/ecma_6/shell.js
index 06be6f2db..756da9f36 100644
--- a/js/src/tests/ecma_6/shell.js
+++ b/js/src/tests/ecma_6/shell.js
@@ -3,21 +3,43 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 (function(global) {
-  /** Yield every permutation of the elements in some array. */
-  global.Permutations = function* Permutations(items) {
-      if (items.length == 0) {
-          yield [];
-      } else {
-          items = items.slice(0);
-          for (let i = 0; i < items.length; i++) {
-              let swap = items[0];
-              items[0] = items[i];
-              items[i] = swap;
-              for (let e of Permutations(items.slice(1, items.length)))
-                  yield [items[0]].concat(e);
-          }
-      }
-  };
+    /** Yield every permutation of the elements in some array. */
+    global.Permutations = function* Permutations(items) {
+        if (items.length == 0) {
+            yield [];
+        } else {
+            items = items.slice(0);
+            for (let i = 0; i < items.length; i++) {
+                let swap = items[0];
+                items[0] = items[i];
+                items[i] = swap;
+                for (let e of Permutations(items.slice(1, items.length)))
+                    yield [items[0]].concat(e);
+            }
+        }
+    };
+
+    /** Make an iterator with a return method. */
+    global.makeIterator = function makeIterator(overrides) {
+        var throwMethod;
+        if (overrides && overrides.throw)
+            throwMethod = overrides.throw;
+        var iterator = {
+            throw: throwMethod,
+            next: function(x) {
+                if (overrides && overrides.next)
+                    return overrides.next(x);
+                return { done: false };
+            },
+            return: function(x) {
+                if (overrides && overrides.ret)
+                    return overrides.ret(x);
+                return { done: true };
+            }
+        };
+
+        return function() { return iterator; };
+    };
 })(this);
 
 if (typeof assertThrowsInstanceOf === 'undefined') {