61 lines
2 KiB
JavaScript
61 lines
2 KiB
JavaScript
test("deleting object properties", () => {
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const o = {};
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o.x = 1;
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o.y = 2;
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o.z = 3;
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expect(Object.getOwnPropertyNames(o)).toHaveLength(3);
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expect(delete o.x).toBeTrue();
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expect(o.hasOwnProperty("x")).toBeFalse();
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expect(o.hasOwnProperty("y")).toBeTrue();
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expect(o.hasOwnProperty("z")).toBeTrue();
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expect(Object.getOwnPropertyNames(o)).toHaveLength(2);
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expect(delete o.y).toBeTrue();
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expect(o.hasOwnProperty("x")).toBeFalse();
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expect(o.hasOwnProperty("y")).toBeFalse();
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expect(o.hasOwnProperty("z")).toBeTrue();
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expect(Object.getOwnPropertyNames(o)).toHaveLength(1);
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expect(delete o.z).toBeTrue();
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expect(o.hasOwnProperty("x")).toBeFalse();
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expect(o.hasOwnProperty("y")).toBeFalse();
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expect(o.hasOwnProperty("z")).toBeFalse();
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expect(Object.getOwnPropertyNames(o)).toHaveLength(0);
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});
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test("deleting array indices", () => {
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const a = [3, 5, 7];
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expect(Object.getOwnPropertyNames(a)).toHaveLength(4);
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expect(delete a[0]).toBeTrue();
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expect(a.hasOwnProperty(0)).toBeFalse();
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expect(a.hasOwnProperty(1)).toBeTrue();
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expect(a.hasOwnProperty(2)).toBeTrue();
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expect(Object.getOwnPropertyNames(a)).toHaveLength(3);
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expect(delete a[1]).toBeTrue();
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expect(a.hasOwnProperty(0)).toBeFalse();
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expect(a.hasOwnProperty(1)).toBeFalse();
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expect(a.hasOwnProperty(2)).toBeTrue();
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expect(Object.getOwnPropertyNames(a)).toHaveLength(2);
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expect(delete a[2]).toBeTrue();
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expect(a.hasOwnProperty(0)).toBeFalse();
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expect(a.hasOwnProperty(1)).toBeFalse();
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expect(a.hasOwnProperty(2)).toBeFalse();
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expect(Object.getOwnPropertyNames(a)).toHaveLength(1);
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expect(delete a["42"]).toBeTrue();
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expect(Object.getOwnPropertyNames(a)).toHaveLength(1);
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});
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test("deleting non-configurable property", () => {
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const q = {};
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Object.defineProperty(q, "foo", { value: 1, writable: false, enumerable: false });
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expect(q.foo).toBe(1);
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expect(delete q.foo).toBeFalse();
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expect(q.hasOwnProperty("foo")).toBeTrue();
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});
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