b1441a47b1
Before this it would always go through the native setter thus modifying the array but now you can set length to anything
117 lines
3.4 KiB
JavaScript
117 lines
3.4 KiB
JavaScript
describe("errors", () => {
|
|
test("invalid array length value", () => {
|
|
var a = [1, 2, 3];
|
|
[undefined, "foo", -1, Infinity, -Infinity, NaN].forEach(value => {
|
|
expect(() => {
|
|
a.length = value;
|
|
}).toThrowWithMessage(RangeError, "Invalid array length");
|
|
expect(a).toHaveLength(3);
|
|
});
|
|
});
|
|
});
|
|
|
|
describe("normal behavior", () => {
|
|
test("extend array by setting length", () => {
|
|
var a = [1, 2, 3];
|
|
a.length = 5;
|
|
expect(a).toEqual([1, 2, 3, undefined, undefined]);
|
|
});
|
|
|
|
test("truncate array by setting length", () => {
|
|
var a = [1, 2, 3];
|
|
a.length = 2;
|
|
expect(a).toEqual([1, 2]);
|
|
a.length = 0;
|
|
expect(a).toEqual([]);
|
|
});
|
|
|
|
test("length value is coerced to number if possible", () => {
|
|
var a = [1, 2, 3];
|
|
a.length = "42";
|
|
expect(a).toHaveLength(42);
|
|
a.length = [];
|
|
expect(a).toHaveLength(0);
|
|
a.length = true;
|
|
expect(a).toHaveLength(1);
|
|
});
|
|
|
|
test("setting a huge array length", () => {
|
|
var a = [];
|
|
a.length = 0x80000000;
|
|
expect(a.length).toEqual(0x80000000);
|
|
|
|
var b = [];
|
|
b.length = 0x80000001;
|
|
expect(b.length).toEqual(0x80000001);
|
|
});
|
|
|
|
test("should not remove non-configurable values", () => {
|
|
var a = [1, undefined, 3];
|
|
Object.defineProperty(a, 1, { configurable: false, value: 2 });
|
|
expect(a.length).toEqual(3);
|
|
|
|
expect((a.length = 1)).toEqual(1);
|
|
expect(a.length).toEqual(2);
|
|
expect(a[1]).toEqual(2);
|
|
});
|
|
});
|
|
|
|
describe("behavior when obj has Array prototype", () => {
|
|
function ArrExtend() {}
|
|
ArrExtend.prototype = [10, 11, 12];
|
|
|
|
test("Has the properties from prototype", () => {
|
|
var arr = new ArrExtend();
|
|
expect(arr.length).toEqual(3);
|
|
expect(arr[0]).toEqual(10);
|
|
expect(arr[1]).toEqual(11);
|
|
expect(arr[2]).toEqual(12);
|
|
});
|
|
|
|
test("Can override length to any value", () => {
|
|
[null, "Hello friends :^)", -6, 0].forEach(value => {
|
|
var arr = new ArrExtend();
|
|
arr.length = value;
|
|
expect(arr.length).toEqual(value);
|
|
|
|
// should not wipe high values
|
|
expect(arr[0]).toEqual(10);
|
|
expect(arr[1]).toEqual(11);
|
|
expect(arr[2]).toEqual(12);
|
|
});
|
|
});
|
|
|
|
test("Can call array methods", () => {
|
|
var arr = new ArrExtend();
|
|
arr.push(1);
|
|
expect(arr.length).toEqual(4);
|
|
expect(arr[3]).toEqual(1);
|
|
});
|
|
|
|
test("If length overwritten uses that value", () => {
|
|
[null, "Hello friends :^)", -6, 0].forEach(value => {
|
|
var arr = new ArrExtend();
|
|
arr.length = value;
|
|
expect(arr.length).toEqual(value);
|
|
|
|
arr.push(99);
|
|
expect(arr.length).toEqual(1);
|
|
expect(arr[0]).toEqual(99);
|
|
|
|
// should not wipe higher value
|
|
expect(arr[1]).toEqual(11);
|
|
expect(arr[2]).toEqual(12);
|
|
|
|
arr.push(100);
|
|
|
|
expect(arr.length).toEqual(2);
|
|
expect(arr[1]).toEqual(100);
|
|
|
|
arr.length = 0;
|
|
// should not wipe values since we are not an array
|
|
expect(arr[0]).toEqual(99);
|
|
expect(arr[1]).toEqual(100);
|
|
expect(arr[2]).toEqual(12);
|
|
});
|
|
});
|
|
});
|