serializer/src/serializer.test.ts

import { Serializer } from "./serializer";

class TestSerializerObj1 {
  a: number;
  constructor(a = 0) {
    this.a = a;
  }
}

class TestSerializerObj2 {
  a = () => 1
  b = [(obj: any) => 2]
}

class TestSerializerObj3 {
  a = [1, 2];
  postUnserialize() {
    this.a.push(3);
  }
}

class TestSerializerObj4 extends TestSerializerObj1 {
}

const TEST_NS = {
  TestSerializerObj1,
  TestSerializerObj2,
  TestSerializerObj3,
};

const TEST_NS_FLAT = [
  TestSerializerObj1,
  TestSerializerObj2,
  TestSerializerObj3,
];

const TEST_NS_RENAME = {
  ob1: TestSerializerObj1,
  ob2: TestSerializerObj2,
  ob3: TestSerializerObj3,
}

describe("Serializer", () => {
  function checkReversability(obj: any, namespace: any = TEST_NS): any {
    var serializer = new Serializer(namespace);
    var data = serializer.serialize(obj);
    serializer = new Serializer(namespace);
    var loaded = serializer.unserialize(data);
    expect(loaded).toEqual(obj);
    return loaded;
  }

  it("serializes simple objects", () => {
    var obj = {
      "a": 5,
      "b": null,
      "c": [{ "a": 2 }, "test"]
    };
    checkReversability(obj);
  });

  it("restores objects constructed from class", () => {
    let loaded = checkReversability(new TestSerializerObj1(5));
    expect(loaded.a).toBe(5);
    expect(loaded).toBeInstanceOf(TestSerializerObj1);

    loaded = checkReversability(new TestSerializerObj1(5), TEST_NS_FLAT);
    expect(loaded.a).toBe(5);
    expect(loaded).toBeInstanceOf(TestSerializerObj1);

    loaded = checkReversability(new TestSerializerObj1(5), TEST_NS_RENAME);
    expect(loaded.a).toBe(5);
    expect(loaded).toBeInstanceOf(TestSerializerObj1);
  });

  it("stores one version of the same object", () => {
    var a = new TestSerializerObj1(8);
    var b = new TestSerializerObj1(8);
    var c = {
      'r': a,
      's': ["test", a],
      't': a,
      'u': b
    };
    var loaded = checkReversability(c);
    expect(loaded.t).toBe(loaded.r);
    expect(loaded.s[1]).toBe(loaded.r);
    expect(loaded.u).not.toBe(loaded.r);
  });

  it("handles circular references", () => {
    var a: any = { b: {} };
    a.b.c = a;

    checkReversability(a);
  });

  it("ignores some classes", () => {
    let serializer = new Serializer(TEST_NS);
    serializer.addIgnoredClass("TestSerializerObj1");

    let data = serializer.serialize({ a: 5, b: new TestSerializerObj1() });
    let loaded = serializer.unserialize(data);

    expect(loaded).toEqual({ a: 5, b: undefined });

    serializer = new Serializer(TEST_NS);
    serializer.addIgnoredClass(TestSerializerObj1);

    data = serializer.serialize({ a: 5, b: new TestSerializerObj1() });
    loaded = serializer.unserialize(data);

    expect(loaded).toEqual({ a: 5, b: undefined });

    serializer = new Serializer(TEST_NS_RENAME);
    serializer.addIgnoredClass(TestSerializerObj1);

    data = serializer.serialize({ a: 5, b: new TestSerializerObj1() });
    loaded = serializer.unserialize(data);

    expect(loaded).toEqual({ a: 5, b: undefined });
  });

  it("ignores functions", () => {
    let serializer = new Serializer(TEST_NS);
    let data = serializer.serialize({ obj: new TestSerializerObj2() });
    let loaded = serializer.unserialize(data);

    let expected = <any>new TestSerializerObj2();
    expected.a = undefined;
    expected.b[0] = undefined;
    expect(loaded).toEqual({ obj: expected });
  });

  it("calls specific postUnserialize", () => {
    let serializer = new Serializer(TEST_NS);
    let data = serializer.serialize({ obj: new TestSerializerObj3() });
    let loaded = serializer.unserialize(data);

    let expected = new TestSerializerObj3();
    expected.a = [1, 2, 3];
    expect(loaded).toEqual({ obj: expected });
  });

  it("handles missing classes", () => {
    jest.spyOn(console, "error").mockImplementation();
    let serializer = new Serializer(TEST_NS);
    let data = serializer.serialize({ obj: new TestSerializerObj4() });
    let loaded = serializer.unserialize(data);
    expect(loaded).toEqual({ obj: { a: 0 } });
    expect(console.error).toHaveBeenCalledWith("Can't find class", "TestSerializerObj4");
  });

  it("uses namespace alias to protect from property mangling", () => {
    const data = {
      a: new TestSerializerObj1(1),
      b: new TestSerializerObj1(2),
      c: [new TestSerializerObj1(3)],
    };

    const serializer1 = new Serializer(TEST_NS);
    const serializer2 = new Serializer(TEST_NS_RENAME);

    const dumped1 = serializer1.serialize(data);
    const dumped2 = serializer2.serialize(data);

    expect(dumped1.length).toBeGreaterThan(dumped2.length);

    expect(serializer1.unserialize(dumped1)).toEqual(data);
    expect(serializer2.unserialize(dumped2)).toEqual(data);
  });
});