// Copyright (C) 2020 Alexey Shvayka. All rights reserved. // This code is governed by the BSD license found in the LICENSE file. /*--- esid: sec-function.prototype.bind description: > "length" value of a bound function defaults to 0. Non-own and non-number "length" values of target function are ignored. info: | Function.prototype.bind ( thisArg, ...args ) [...] 5. Let targetHasLength be ? HasOwnProperty(Target, "length"). 6. If targetHasLength is true, then a. Let targetLen be ? Get(Target, "length"). b. If Type(targetLen) is not Number, let L be 0. c. Else, i. Set targetLen to ! ToInteger(targetLen). ii. Let L be the larger of 0 and the result of targetLen minus the number of elements of args. 7. Else, let L be 0. 8. Perform ! SetFunctionLength(F, L). [...] features: [Symbol] ---*/ function foo() {} Object.defineProperty(foo, "length", {value: undefined}); assert.sameValue(foo.bind(null, 1).length, 0, "undefined"); Object.defineProperty(foo, "length", {value: null}); assert.sameValue(foo.bind(null, 1).length, 0, "null"); Object.defineProperty(foo, "length", {value: true}); assert.sameValue(foo.bind(null, 1).length, 0, "boolean"); Object.defineProperty(foo, "length", {value: "1"}); assert.sameValue(foo.bind(null, 1).length, 0, "string"); Object.defineProperty(foo, "length", {value: Symbol("1")}); assert.sameValue(foo.bind(null, 1).length, 0, "symbol"); Object.defineProperty(foo, "length", {value: new Number(1)}); assert.sameValue(foo.bind(null, 1).length, 0, "Number object"); function bar() {} Object.setPrototypeOf(bar, {length: 42}); assert(delete bar.length); var bound = Function.prototype.bind.call(bar, null, 1); assert.sameValue(bound.length, 0, "not own"); reportCompare(0, 0);