| // Copyright 2013 the V8 project authors. All rights reserved. | 
 | // Redistribution and use in source and binary forms, with or without | 
 | // modification, are permitted provided that the following conditions are | 
 | // met: | 
 | // | 
 | //     * Redistributions of source code must retain the above copyright | 
 | //       notice, this list of conditions and the following disclaimer. | 
 | //     * Redistributions in binary form must reproduce the above | 
 | //       copyright notice, this list of conditions and the following | 
 | //       disclaimer in the documentation and/or other materials provided | 
 | //       with the distribution. | 
 | //     * Neither the name of Google Inc. nor the names of its | 
 | //       contributors may be used to endorse or promote products derived | 
 | //       from this software without specific prior written permission. | 
 | // | 
 | // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS | 
 | // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT | 
 | // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR | 
 | // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT | 
 | // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, | 
 | // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT | 
 | // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, | 
 | // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY | 
 | // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | 
 | // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE | 
 | // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | 
 |  | 
 | // Test for-of semantics. | 
 |  | 
 | "use strict"; | 
 |  | 
 |  | 
 | // First, some helpers. | 
 |  | 
 | function* values() { | 
 |   for (var i = 0; i < arguments.length; i++) { | 
 |     yield arguments[i]; | 
 |   } | 
 | } | 
 |  | 
 | function wrap_iterator(iterator) { | 
 |     var iterable = {}; | 
 |     iterable[Symbol.iterator] = function() { return iterator; }; | 
 |     return iterable; | 
 | } | 
 |  | 
 | function integers_until(max) { | 
 |   function next() { | 
 |     var ret = { value: this.n, done: this.n == max }; | 
 |     this.n++; | 
 |     return ret; | 
 |   } | 
 |   return wrap_iterator({ next: next, n: 0 }); | 
 | } | 
 |  | 
 | function results(results) { | 
 |   var i = 0; | 
 |   function next() { | 
 |     return results[i++]; | 
 |   } | 
 |   return wrap_iterator({ next: next }); | 
 | } | 
 |  | 
 | function* integers_from(n) { | 
 |   while (1) yield n++; | 
 | } | 
 |  | 
 | // A destructive append. | 
 | function append(x, tail) { | 
 |   tail[tail.length] = x; | 
 |   return tail; | 
 | } | 
 |  | 
 | function sum(x, tail) { | 
 |   return x + tail; | 
 | } | 
 |  | 
 | function fold(cons, seed, iterable) { | 
 |   for (var x of iterable) { | 
 |     seed = cons(x, seed); | 
 |   } | 
 |   return seed; | 
 | } | 
 |  | 
 | function* take(iterable, n) { | 
 |   if (n == 0) return; | 
 |   for (let x of iterable) { | 
 |     yield x; | 
 |     if (--n == 0) break; | 
 |   } | 
 | } | 
 |  | 
 | function nth(iterable, n) { | 
 |   for (let x of iterable) { | 
 |     if (n-- == 0) return x; | 
 |   } | 
 |   throw "unreachable"; | 
 | } | 
 |  | 
 | function* skip_every(iterable, n) { | 
 |   var i = 0; | 
 |   for (let x of iterable) { | 
 |     if (++i % n == 0) continue; | 
 |     yield x; | 
 |   } | 
 | } | 
 |  | 
 | function* iter_map(iterable, f) { | 
 |   for (var x of iterable) { | 
 |     yield f(x); | 
 |   } | 
 | } | 
 | function nested_fold(cons, seed, iterable) { | 
 |   var visited = [] | 
 |   for (let x of iterable) { | 
 |     for (let y of x) { | 
 |       seed = cons(y, seed); | 
 |     } | 
 |   } | 
 |   return seed; | 
 | } | 
 |  | 
 | function* unreachable(iterable) { | 
 |   for (let x of iterable) { | 
 |     throw "not reached"; | 
 |   } | 
 | } | 
 |  | 
 | function one_time_getter(o, prop, val) { | 
 |   function set_never() { throw "unreachable"; } | 
 |   var gotten = false; | 
 |   function get_once() { | 
 |     if (gotten) throw "got twice"; | 
 |     gotten = true; | 
 |     return val; | 
 |   } | 
 |   Object.defineProperty(o, prop, {get: get_once, set: set_never}) | 
 |   return o; | 
 | } | 
 |  | 
 | function never_getter(o, prop) { | 
 |   function never() { throw "unreachable"; } | 
 |   Object.defineProperty(o, prop, {get: never, set: never}) | 
 |   return o; | 
 | } | 
 |  | 
 | function remove_next_after(iterable, n) { | 
 |   var iterator = iterable[Symbol.iterator](); | 
 |   function next() { | 
 |     if (n-- == 0) delete this.next; | 
 |     return iterator.next(); | 
 |   } | 
 |   return wrap_iterator({ next: next }); | 
 | } | 
 |  | 
 | function poison_next_after(iterable, n) { | 
 |   var iterator = iterable[Symbol.iterator](); | 
 |   function next() { | 
 |     return iterator.next(); | 
 |   } | 
 |   function next_getter() { | 
 |     if (n-- < 0) | 
 |       throw "poisoned"; | 
 |     return next; | 
 |   } | 
 |   var o = {}; | 
 |   Object.defineProperty(o, 'next', { get: next_getter }); | 
 |   return wrap_iterator(o); | 
 | } | 
 |  | 
 | // Now, the tests. | 
 |  | 
 | // Non-generator iterators. | 
 | assertEquals(45, fold(sum, 0, integers_until(10))); | 
 | // Generator iterators. | 
 | assertEquals([1, 2, 3], fold(append, [], values(1, 2, 3))); | 
 | // Break. | 
 | assertEquals(45, fold(sum, 0, take(integers_from(0), 10))); | 
 | // Continue. | 
 | assertEquals(90, fold(sum, 0, take(skip_every(integers_from(0), 2), 10))); | 
 | // Return. | 
 | assertEquals(10, nth(integers_from(0), 10)); | 
 | // Nested for-of. | 
 | assertEquals([0, 0, 1, 0, 1, 2, 0, 1, 2, 3], | 
 |              nested_fold(append, | 
 |                          [], | 
 |                          iter_map(integers_until(5), integers_until))); | 
 | // Result objects with sparse fields. | 
 | assertEquals([undefined, 1, 2, 3], | 
 |              fold(append, [], | 
 |                   results([{ done: false }, | 
 |                            { value: 1, done: false }, | 
 |                            // A missing "done" is the same as undefined, which | 
 |                            // is false. | 
 |                            { value: 2 }, | 
 |                            // Not done. | 
 |                            { value: 3, done: 0 }, | 
 |                            // Done. | 
 |                            { value: 4, done: 42 }]))); | 
 | // Results that are not objects. | 
 | assertThrows(function() { | 
 |   assertEquals([undefined, undefined, undefined], | 
 |                fold(append, [], | 
 |                     results([10, "foo", /qux/, { value: 37, done: true }]))); | 
 | }, TypeError); | 
 | // Getters (shudder). | 
 | assertEquals([1, 2], | 
 |              fold(append, [], | 
 |                   results([one_time_getter({ value: 1 }, 'done', false), | 
 |                            one_time_getter({ done: false }, 'value', 2), | 
 |                            { value: 37, done: true }, | 
 |                            never_getter(never_getter({}, 'done'), 'value')]))); | 
 |  | 
 | // Unlike the case with for-in, null and undefined cause an error. | 
 | assertThrows('fold(sum, 0, unreachable(null))', TypeError); | 
 | assertThrows('fold(sum, 0, unreachable(undefined))', TypeError); | 
 |  | 
 | // Other non-iterators do cause an error. | 
 | assertThrows('fold(sum, 0, unreachable({}))', TypeError); | 
 | assertThrows('fold(sum, 0, unreachable(false))', TypeError); | 
 | assertThrows('fold(sum, 0, unreachable(37))', TypeError); | 
 |  | 
 | // "next" is looked up each time. | 
 | assertThrows('fold(sum, 0, remove_next_after(integers_until(10), 5))', | 
 |              TypeError); | 
 | // It is not called at any other time. | 
 | assertEquals(45, | 
 |              fold(sum, 0, remove_next_after(integers_until(10), 10))); | 
 | // It is not looked up too many times. | 
 | assertEquals(45, | 
 |              fold(sum, 0, poison_next_after(integers_until(10), 10))); | 
 |  | 
 | function labelled_continue(iterable) { | 
 |   var n = 0; | 
 | outer: | 
 |   while (true) { | 
 |     n++; | 
 |     for (var x of iterable) continue outer; | 
 |     break; | 
 |   } | 
 |   return n; | 
 | } | 
 | assertEquals(11, labelled_continue(integers_until(10))); | 
 |  | 
 | function labelled_break(iterable) { | 
 |   var n = 0; | 
 | outer: | 
 |   while (true) { | 
 |     n++; | 
 |     for (var x of iterable) break outer; | 
 |   } | 
 |   return n; | 
 | } | 
 | assertEquals(1, labelled_break(integers_until(10))); | 
 |  | 
 | // Test continue/break in catch. | 
 | function catch_control(iterable, k) { | 
 |   var n = 0; | 
 |   for (var x of iterable) { | 
 |     try { | 
 |       return k(x); | 
 |     } catch (e) { | 
 |       if (e == "continue") continue; | 
 |       else if (e == "break") break; | 
 |       else throw e; | 
 |     } | 
 |   } while (false); | 
 |   return false; | 
 | } | 
 | assertEquals(false, | 
 |              catch_control(integers_until(10), | 
 |                            function() { throw "break" })); | 
 | assertEquals(false, | 
 |              catch_control(integers_until(10), | 
 |                            function() { throw "continue" })); | 
 | assertEquals(5, | 
 |              catch_control(integers_until(10), | 
 |                            function(x) { | 
 |                              if (x == 5) return x; | 
 |                              throw "continue"; | 
 |                            })); | 
 |  | 
 | // Test continue/break in try. | 
 | function try_control(iterable, k) { | 
 |   var n = 0; | 
 |   for (var x of iterable) { | 
 |     try { | 
 |       var e = k(x); | 
 |       if (e == "continue") continue; | 
 |       else if (e == "break") break; | 
 |       return e; | 
 |     } catch (e) { | 
 |       throw e; | 
 |     } | 
 |   } while (false); | 
 |   return false; | 
 | } | 
 | assertEquals(false, | 
 |              try_control(integers_until(10), | 
 |                          function() { return "break" })); | 
 | assertEquals(false, | 
 |              try_control(integers_until(10), | 
 |                          function() { return "continue" })); | 
 | assertEquals(5, | 
 |              try_control(integers_until(10), | 
 |                          function(x) { return (x == 5) ? x : "continue" })); | 
 |  | 
 | // TODO(neis,cbruni): Enable once the corresponding traps work again. | 
 | // Proxy results, with getters. | 
 | // function transparent_proxy(x) { | 
 | //   return new Proxy({}, { | 
 | //     get: function(receiver, name) { return x[name]; } | 
 | //   }); | 
 | // } | 
 | // assertEquals([1, 2], | 
 | //              fold(append, [], | 
 | //                   results([one_time_getter({ value: 1 }, 'done', false), | 
 | //                            one_time_getter({ done: false }, 'value', 2), | 
 | //                            { value: 37, done: true }, | 
 | //                            never_getter(never_getter({}, 'done'), 'value')] | 
 | //                           .map(transparent_proxy)))); | 
 |  | 
 | // Proxy iterators. | 
 | // function poison_proxy_after(iterable, n) { | 
 | //   var iterator = iterable[Symbol.iterator](); | 
 | //   return wrap_iterator(new Proxy({}, { | 
 | //     get: function(receiver, name) { | 
 | //       if (name == 'next' && n-- < 0) throw "unreachable"; | 
 | //       return iterator[name]; | 
 | //     }, | 
 | //     // Needed for integers_until(10)'s this.n++. | 
 | //     set: function(receiver, name, val) { | 
 | //       return iterator[name] = val; | 
 | //     } | 
 | //   })); | 
 | // } | 
 | // assertEquals(45, fold(sum, 0, poison_proxy_after(integers_until(10), 10))); | 
 |  | 
 |  | 
 | function test_iterator_result_object_non_object(value, descr) { | 
 |   var arr = []; | 
 |   var ex; | 
 |   var message = 'Iterator result ' + (descr || value) + ' is not an object'; | 
 |   try { | 
 |     fold(append, arr, | 
 |          results([{value: 1}, {}, value, {value: 2}, {done: true}])); | 
 |   } catch (e) { | 
 |     ex = e; | 
 |   } | 
 |   assertInstanceof(ex, TypeError); | 
 |   assertEquals(message, ex.message); | 
 |   assertArrayEquals([1, undefined], arr); | 
 | } | 
 | test_iterator_result_object_non_object(null); | 
 | test_iterator_result_object_non_object(undefined); | 
 | test_iterator_result_object_non_object(42); | 
 | test_iterator_result_object_non_object('abc'); | 
 | test_iterator_result_object_non_object(false); | 
 | test_iterator_result_object_non_object(Symbol('x'), 'Symbol(x)'); |