Strict mode Passingnon-Strict mode Passing
Features:
- Symbol.toPrimitive
// Copyright (C) 2016 the V8 project authors. All rights reserved. // This code is governed by the BSD license found in the LICENSE file. /*--- esid: sec-addition-operator-plus-runtime-semantics-evaluation es6id: 12.7.3.1 description: > Behavior when coercion via `Symbol.toPrimitive` yields an Object info: | [...] 5. Let lprim be ? ToPrimitive(lval). 6. Let rprim be ? ToPrimitive(rval). [...] ES6 Section 7.1.1 ToPrimitive ( input [, PreferredType] ) [...] 4. Let exoticToPrim be GetMethod(input, @@toPrimitive). 5. ReturnIfAbrupt(exoticToPrim). 6. If exoticToPrim is not undefined, then a. Let result be Call(exoticToPrim, input, «hint»). b. ReturnIfAbrupt(result). c. If Type(result) is not Object, return result. d. Throw a TypeError exception. features: [Symbol.toPrimitive] ---*/ var y = {}; var retVal; y[Symbol.toPrimitive] = function() { return retVal; }; retVal = {}; assert.throws(TypeError, function() { 0 + y; }, 'ordinary object value, right-hand side'); assert.throws(TypeError, function() { y + 0; }, 'ordinary object value, left-hand side'); retVal = (function() { return arguments; }()); assert.throws(TypeError, function() { 0 + y; }, 'arguments exotic object value, right-hand side'); assert.throws(TypeError, function() { y + 0; }, 'arguments exotic object value, left-hand side');