// Copyright 2015 the V8 project authors. All rights reserved. // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. // Flags: --harmony-do-expressions --allow-natives-syntax function returnValue(v) { return v; } function MyError() {} var global = this; function TestBasic() { // Looping and lexical declarations assertEquals(512, returnValue(do { let n = 2; for (let i = 0; i < 4; i++) n <<= 2; })); // Strings do the right thing assertEquals("spooky halloween", returnValue(do { "happy halloween".replace('happy', 'spooky'); })); // Do expressions with no completion produce an undefined value assertEquals(undefined, returnValue(do {})); assertEquals(undefined, returnValue(do { var x = 99; })); assertEquals(undefined, returnValue(do { function f() {}; })); assertEquals(undefined, returnValue(do { let z = 33; })); // Propagation of exception assertThrows(function() { (do { throw new MyError(); "potatoes"; }); }, MyError); assertThrows(function() { return do { throw new MyError(); "potatoes"; }; }, MyError); // Return value within do-block overrides `return |do-expression|` assertEquals("inner-return", (function() { return "outer-return" + do { return "inner-return"; ""; }; })()); var count = 0, n = 1; // Breaking out |do-expression| assertEquals(3, (function() { for (var i = 0; i < 10; ++i) (count += 2 * do { if (i === 3) break; ++n }); return i; })()); // (2 * 2) + (2 * 3) + (2 * 4) assertEquals(18, count); // Continue in |do-expression| count = 0, n = 1; assertEquals([1, 3, 5, 7, 9], (function() { var values = []; for (var i = 0; i < 10; ++i) { count += 2 * (do { if ((i & 1) === 0) continue; values.push(i); ++n; }) + 1; } // (2*2) + 1 + (2*3) + 1 + (2*4) + 1 + (2*5) + 1 + (2*6) + 1 return values; })()); assertEquals(count, 45); assertThrows("(do { break; });", SyntaxError); assertThrows("(do { continue; });", SyntaxError); // Real-world use case for desugaring var array = [1, 2, 3, 4, 5], iterable = [6, 7, 8,9]; assertEquals([1, 2, 3, 4, 5, 6, 7, 8, 9], do { for (var element of iterable) array.push(element); array; }); // Nested do-expressions assertEquals(125, do { (do { (do { 5 * 5 * 5 }) }) }); // Directives are not honoured (do { "use strict"; foo = 80; assertEquals(foo, 80); }); // Non-empty operand stack testing var O = { method1() { let x = 256; return x + do { for (var i = 0; i < 4; ++i) x += i; } + 17; }, method2() { let x = 256; this.reset(); return x + do { for (var i = 0; i < this.length(); ++i) x += this.index() * 2; }; }, _index: 0, index() { return ++this._index; }, _length: 4, length() { return this._length; }, reset() { this._index = 0; } }; assertEquals(535, O["method" + do { 1 } + ""]()); assertEquals(532, O["method" + do { ({ valueOf() { return "2"; } }); }]()); assertEquals(532, O[ do { let s = ""; for (let c of "method") s += c; } + "2"]()); } TestBasic(); function TestDeoptimization1() { function f(v) { return 88 + do { v.a * v.b + v.c; }; } var o1 = {}; o1.a = 10; o1.b = 5; o1.c = 50; var o2 = {}; o2.c = 100; o2.a = 10; o2.b = 10; assertEquals(188, f(o1)); assertEquals(188, f(o1)); %OptimizeFunctionOnNextCall(f); assertEquals(188, f(o1)); assertOptimized(f); assertEquals(288, f(o2)); assertUnoptimized(f); assertEquals(288, f(o2)); } TestDeoptimization1(); function TestInParameterInitializers() { var first_name = "George"; var last_name = "Jetson"; function fn1(name = do { first_name + " " + last_name }) { return name; } assertEquals("George Jetson", fn1()); var _items = [1, 2, 3, NaN, 4, 5]; function fn2(items = do { let items = []; for (var el of _items) { if (el !== el) { items; break; } items.push(el), items; } }) { return items; } assertEquals([1, 2, 3], fn2()); function thrower() { throw new MyError(); } function fn3(exception = do { try { thrower(); } catch (e) { e } }) { return exception; } assertDoesNotThrow(fn3); assertInstanceof(fn3(), MyError); function fn4(exception = do { throw new MyError() }) {} function catcher(fn) { try { fn(); assertUnreachable("fn() initializer should throw"); } catch (e) { assertInstanceof(e, MyError); } } catcher(fn4); } TestInParameterInitializers(); function TestWithEval() { (function sloppy1() { assertEquals(do { eval("var x = 5"), x }, 5); assertEquals(x, 5); })(); assertThrows(function strict1() { "use strict"; (do { eval("var x = 5"), x }, 5); }, ReferenceError); assertThrows(function strict2() { (do { eval("'use strict'; var x = 5"), x }, 5); }, ReferenceError); } TestWithEval(); function TestHoisting() { (do { var a = 1; }); assertEquals(a, 1); assertEquals(global.a, undefined); (do { for (let it of [1, 2, 3, 4, 5]) { var b = it; } }); assertEquals(b, 5); assertEquals(global.b, undefined); { let x = 1 // TODO(caitp): ensure VariableStatements in |do-expressions| in parameter // initializers, are evaluated in the same VariableEnvironment as they would // be for eval(). // function f1(a = do { var x = 2 }, b = x) { return b } // assertEquals(1, f1()) // function f2(a = x, b = do { var x = 2 }) { return a } // assertEquals(1, f2()) function f3({a = do { var x = 2 }, b = x}) { return b } assertEquals(2, f3({})) function f4({a = x, b = do { var x = 2 }}) { return b } assertEquals(undefined, f4({})) function f5(a = do { var y = 0 }) {} assertThrows(() => y, ReferenceError) } // TODO(caitp): Always block-scope function declarations in |do| expressions //(do { // assertEquals(true, inner_func()); // function inner_func() { return true; } //}); //assertThrows(function() { return innerFunc(); }, ReferenceError); } TestHoisting(); // v8:4661 function tryFinallySimple() { (do { try {} finally {} }); } tryFinallySimple(); tryFinallySimple(); tryFinallySimple(); tryFinallySimple(); var finallyRanCount = 0; function tryFinallyDoExpr() { return (do { try { throw "BOO"; } catch (e) { "Caught: " + e + " (" + finallyRanCount + ")" } finally { ++finallyRanCount; } }); } assertEquals("Caught: BOO (0)", tryFinallyDoExpr()); assertEquals(1, finallyRanCount); assertEquals("Caught: BOO (1)", tryFinallyDoExpr()); assertEquals(2, finallyRanCount); assertEquals("Caught: BOO (2)", tryFinallyDoExpr()); assertEquals(3, finallyRanCount); assertEquals("Caught: BOO (3)", tryFinallyDoExpr()); assertEquals(4, finallyRanCount); function TestOSR() { var numbers = do { let nums = []; for (let i = 0; i < 1000; ++i) { let value = (Math.random() * 100) | 0; nums.push(value === 0 ? 1 : value), nums; } }; assertEquals(numbers.length, 1000); } for (var i = 0; i < 64; ++i) TestOSR();