matchers.test.js

/**
 * Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 */

const {stringify} = require('jest-matcher-utils');
const {alignedAnsiStyleSerializer} = require('@jest/test-utils');
const jestExpect = require('../');
const Immutable = require('immutable');
const chalk = require('chalk');
const chalkEnabled = chalk.enabled;

expect.addSnapshotSerializer(alignedAnsiStyleSerializer);

beforeAll(() => {
  chalk.enabled = true;
});

afterAll(() => {
  chalk.enabled = chalkEnabled;
});

/* global BigInt */
const isBigIntDefined = typeof BigInt === 'function';

it('should throw if passed two arguments', () => {
  expect(() => jestExpect('foo', 'bar')).toThrow(
    new Error('Expect takes at most one argument.'),
  );
});

describe('.rejects', () => {
  it('should reject', async () => {
    await jestExpect(Promise.reject(4)).rejects.toBe(4);
    await jestExpect(Promise.reject(4)).rejects.not.toBe(5);
    await jestExpect(Promise.reject(4.2)).rejects.toBeCloseTo(4.2, 5);
    await jestExpect(Promise.reject(3)).rejects.not.toBeCloseTo(4.2, 5);
    await jestExpect(Promise.reject({a: 1, b: 2})).rejects.toMatchObject({
      a: 1,
    });
    await jestExpect(Promise.reject({a: 1, b: 2})).rejects.not.toMatchObject({
      c: 1,
    });
    await jestExpect(
      Promise.reject(new Error('rejectMessage')),
    ).rejects.toMatchObject({message: 'rejectMessage'});
    await jestExpect(Promise.reject(new Error())).rejects.toThrow();
  });

  it('should reject with toThrow', async () => {
    async function fn() {
      throw new Error('some error');
    }
    await jestExpect(fn()).rejects.toThrow('some error');
  });

  ['a', [1], () => {}, {a: 1}].forEach(value => {
    it(`fails non-promise value ${stringify(value)} synchronously`, () => {
      let error;
      try {
        jestExpect(value).rejects.toBe(111);
      } catch (e) {
        error = e;
      }
      expect(error).toBeDefined();
    });

    it(`fails non-promise value ${stringify(value)}`, async () => {
      let error;
      try {
        await jestExpect(value).rejects.toBeDefined();
      } catch (e) {
        error = e;
      }
      expect(error).toBeDefined();
      expect(error.message).toMatchSnapshot();
    });
  });

  [4, null, true, undefined].forEach(value => {
    it(`fails non-promise value ${stringify(value)} synchronously`, () => {
      let error;
      try {
        jestExpect(value).rejects.not.toBe(111);
      } catch (e) {
        error = e;
      }
      expect(error).toBeDefined();
    });

    it(`fails non-promise value ${stringify(value)}`, async () => {
      let error;
      try {
        await jestExpect(value).rejects.not.toBeDefined();
      } catch (e) {
        error = e;
      }
      expect(error).toBeDefined();
      expect(error.message).toMatchSnapshot();
    });
  });

  it('fails for promise that resolves', async () => {
    let error;
    try {
      await jestExpect(Promise.resolve(4)).rejects.toBe(4);
    } catch (e) {
      error = e;
    }
    expect(error).toBeDefined();
    expect(error.message).toMatchSnapshot();
  });
});

describe('.resolves', () => {
  it('should resolve', async () => {
    await jestExpect(Promise.resolve(4)).resolves.toBe(4);
    await jestExpect(Promise.resolve(4)).resolves.not.toBe(5);
    await jestExpect(Promise.resolve(4.2)).resolves.toBeCloseTo(4.2, 5);
    await jestExpect(Promise.resolve(3)).resolves.not.toBeCloseTo(4.2, 5);
    await jestExpect(Promise.resolve({a: 1, b: 2})).resolves.toMatchObject({
      a: 1,
    });
    await jestExpect(Promise.resolve({a: 1, b: 2})).resolves.not.toMatchObject({
      c: 1,
    });
    await jestExpect(
      Promise.resolve(() => {
        throw new Error();
      }),
    ).resolves.toThrow();
  });

  ['a', [1], () => {}, {a: 1}].forEach(value => {
    it(`fails non-promise value ${stringify(value)} synchronously`, () => {
      let error;
      try {
        jestExpect(value).resolves.toBeDefined();
      } catch (e) {
        error = e;
      }
      expect(error).toBeDefined();
      expect(error.message).toMatchSnapshot();
    });

    it(`fails non-promise value ${stringify(value)}`, async () => {
      let error;
      try {
        await jestExpect(value).resolves.toBeDefined();
      } catch (e) {
        error = e;
      }
      expect(error).toBeDefined();
      expect(error.message).toMatchSnapshot();
    });
  });

  [4, null, true, undefined].forEach(value => {
    it(`fails non-promise value ${stringify(value)} synchronously`, () => {
      let error;
      try {
        jestExpect(value).resolves.not.toBeDefined();
      } catch (e) {
        error = e;
      }
      expect(error).toBeDefined();
      expect(error.message).toMatchSnapshot();
    });

    it(`fails non-promise value ${stringify(value)}`, async () => {
      let error;
      try {
        await jestExpect(value).resolves.not.toBeDefined();
      } catch (e) {
        error = e;
      }
      expect(error).toBeDefined();
      expect(error.message).toMatchSnapshot();
    });
  });

  it('fails for promise that rejects', async () => {
    let error;
    try {
      await jestExpect(Promise.reject(4)).resolves.toBe(4);
    } catch (e) {
      error = e;
    }
    expect(error).toBeDefined();
    expect(error.message).toMatchSnapshot();
  });
});

describe('.toBe()', () => {
  it('does not throw', () => {
    jestExpect('a').not.toBe('b');
    jestExpect('a').toBe('a');
    jestExpect(1).not.toBe(2);
    jestExpect(1).toBe(1);
    jestExpect(null).not.toBe(undefined);
    jestExpect(null).toBe(null);
    jestExpect(undefined).toBe(undefined);
    jestExpect(NaN).toBe(NaN);
    if (isBigIntDefined) {
      jestExpect(BigInt(1)).not.toBe(BigInt(2));
      jestExpect(BigInt(1)).not.toBe(1);
      jestExpect(BigInt(1)).toBe(BigInt(1));
    }
  });

  [
    [1, 2],
    [true, false],
    [() => {}, () => {}],
    [{}, {}],
    [{a: 1}, {a: 1}],
    [{a: 1}, {a: 5}],
    [
      {a: () => {}, b: 2},
      {a: expect.any(Function), b: 2},
    ],
    [{a: undefined, b: 2}, {b: 2}],
    [new Date('2020-02-20'), new Date('2020-02-20')],
    [new Date('2020-02-21'), new Date('2020-02-20')],
    [/received/, /expected/],
    [Symbol('received'), Symbol('expected')],
    [new Error('received'), new Error('expected')],
    ['abc', 'cde'],
    ['painless JavaScript testing', 'delightful JavaScript testing'],
    ['', 'compare one-line string to empty string'],
    ['with \ntrailing space', 'without trailing space'],
    ['four\n4\nline\nstring', '3\nline\nstring'],
    [[], []],
    [null, undefined],
    [-0, +0],
  ].forEach(([a, b]) => {
    it(`fails for: ${stringify(a)} and ${stringify(b)}`, () => {
      expect(() => jestExpect(a).toBe(b)).toThrowErrorMatchingSnapshot();
    });
  });

  if (isBigIntDefined) {
    [
      [BigInt(1), BigInt(2)],
      [{a: BigInt(1)}, {a: BigInt(1)}],
    ].forEach(([a, b]) => {
      it(`fails for: ${stringify(a)} and ${stringify(b)}`, () => {
        expect(() => jestExpect(a).toBe(b)).toThrowError('toBe');
      });
    });
  }

  [false, 1, 'a', undefined, null, {}, []].forEach(v => {
    it(`fails for '${stringify(v)}' with '.not'`, () => {
      expect(() => jestExpect(v).not.toBe(v)).toThrowErrorMatchingSnapshot();
    });
  });

  if (isBigIntDefined) {
    [BigInt(1), BigInt('1')].forEach(v => {
      it(`fails for '${stringify(v)}' with '.not'`, () => {
        expect(() => jestExpect(v).not.toBe(v)).toThrowError('toBe');
      });
    });
  }

  it('does not crash on circular references', () => {
    const obj = {};
    obj.circular = obj;

    expect(() => jestExpect(obj).toBe({})).toThrowErrorMatchingSnapshot();
  });

  test('assertion error matcherResult property contains matcher name, expected and actual values', () => {
    const actual = {a: 1};
    const expected = {a: 2};
    try {
      jestExpect(actual).toBe(expected);
    } catch (error) {
      expect(error.matcherResult).toEqual(
        expect.objectContaining({
          actual,
          expected,
          name: 'toBe',
        }),
      );
    }
  });
});

describe('.toStrictEqual()', () => {
  class TestClassA {
    constructor(a, b) {
      this.a = a;
      this.b = b;
    }
  }

  class TestClassB {
    constructor(a, b) {
      this.a = a;
      this.b = b;
    }
  }

  const TestClassC = class Child extends TestClassA {
    constructor(a, b) {
      super(a, b);
    }
  };

  const TestClassD = class Child extends TestClassB {
    constructor(a, b) {
      super(a, b);
    }
  };

  it('does not ignore keys with undefined values', () => {
    expect({
      a: undefined,
      b: 2,
    }).not.toStrictEqual({b: 2});
  });

  it('does not ignore keys with undefined values inside an array', () => {
    expect([{a: undefined}]).not.toStrictEqual([{}]);
  });

  it('does not ignore keys with undefined values deep inside an object', () => {
    expect([{a: [{a: undefined}]}]).not.toStrictEqual([{a: [{}]}]);
  });

  it('passes when comparing same type', () => {
    expect({
      test: new TestClassA(1, 2),
    }).toStrictEqual({test: new TestClassA(1, 2)});
  });

  it('matches the expected snapshot when it fails', () => {
    expect(() =>
      jestExpect({
        test: 2,
      }).toStrictEqual({test: new TestClassA(1, 2)}),
    ).toThrowErrorMatchingSnapshot();

    expect(() =>
      jestExpect({
        test: new TestClassA(1, 2),
      }).not.toStrictEqual({test: new TestClassA(1, 2)}),
    ).toThrowErrorMatchingSnapshot();
  });

  it('displays substring diff', () => {
    const expected =
      'Another caveat is that Jest will not typecheck your tests.';
    const received =
      'Because TypeScript support in Babel is just transpilation, Jest will not type-check your tests as they run.';
    expect(() =>
      jestExpect(received).toStrictEqual(expected),
    ).toThrowErrorMatchingSnapshot();
  });

  it('displays substring diff for multiple lines', () => {
    const expected = [
      '    69 | ',
      "    70 | test('assert.doesNotThrow', () => {",
      '  > 71 |   assert.doesNotThrow(() => {',
      '       |          ^',
      "    72 |     throw Error('err!');",
      '    73 |   });',
      '    74 | });',
      '    at Object.doesNotThrow (__tests__/assertionError.test.js:71:10)',
    ].join('\n');
    const received = [
      '    68 | ',
      "    69 | test('assert.doesNotThrow', () => {",
      '  > 70 |   assert.doesNotThrow(() => {',
      '       |          ^',
      "    71 |     throw Error('err!');",
      '    72 |   });',
      '    73 | });',
      '    at Object.doesNotThrow (__tests__/assertionError.test.js:70:10)',
    ].join('\n');
    expect(() =>
      jestExpect(received).toStrictEqual(expected),
    ).toThrowErrorMatchingSnapshot();
  });

  it('does not pass for different types', () => {
    expect({
      test: new TestClassA(1, 2),
    }).not.toStrictEqual({test: new TestClassB(1, 2)});
  });

  it('does not simply compare constructor names', () => {
    const c = new TestClassC(1, 2);
    const d = new TestClassD(1, 2);
    expect(c.constructor.name).toEqual(d.constructor.name);
    expect({test: c}).not.toStrictEqual({test: d});
  });

  /* eslint-disable no-sparse-arrays */
  it('passes for matching sparse arrays', () => {
    expect([, 1]).toStrictEqual([, 1]);
  });

  it('does not pass when sparseness of arrays do not match', () => {
    expect([, 1]).not.toStrictEqual([undefined, 1]);
    expect([undefined, 1]).not.toStrictEqual([, 1]);
    expect([, , , 1]).not.toStrictEqual([, 1]);
  });

  it('does not pass when equally sparse arrays have different values', () => {
    expect([, 1]).not.toStrictEqual([, 2]);
  });
  /* eslint-enable */
});

describe('.toEqual()', () => {
  /* eslint-disable no-new-wrappers */
  [
    [true, false],
    [1, 2],
    [0, -0],
    [0, Number.MIN_VALUE], // issues/7941
    [Number.MIN_VALUE, 0],
    [0, new Number(0)],
    [new Number(0), 0],
    [new Number(0), new Number(1)],
    ['abc', new String('abc')],
    [new String('abc'), 'abc'],
    [/abc/gsy, /abc/g],
    [{a: 1}, {a: 2}],
    [{a: 5}, {b: 6}],
    [Object.freeze({foo: {bar: 1}}), {foo: {}}],
    ['banana', 'apple'],
    ['1\u{00A0}234,57\u{00A0}$', '1 234,57 $'], // issues/6881
    [
      'type TypeName<T> = T extends Function ? "function" : "object";',
      'type TypeName<T> = T extends Function\n? "function"\n: "object";',
    ],
    [null, undefined],
    [[1], [2]],
    [
      [1, 2],
      [2, 1],
    ],
    [Immutable.List([1]), Immutable.List([2])],
    [Immutable.List([1, 2]), Immutable.List([2, 1])],
    [new Map(), new Set()],
    [new Set([1, 2]), new Set()],
    [new Set([1, 2]), new Set([1, 2, 3])],
    [new Set([[1], [2]]), new Set([[1], [2], [3]])],
    [new Set([[1], [2]]), new Set([[1], [2], [2]])],
    [
      new Set([new Set([1]), new Set([2])]),
      new Set([new Set([1]), new Set([3])]),
    ],
    [Immutable.Set([1, 2]), Immutable.Set()],
    [Immutable.Set([1, 2]), Immutable.Set([1, 2, 3])],
    [Immutable.OrderedSet([1, 2]), Immutable.OrderedSet([2, 1])],
    [
      new Map([
        [1, 'one'],
        [2, 'two'],
      ]),
      new Map([[1, 'one']]),
    ],
    [new Map([['a', 0]]), new Map([['b', 0]])],
    [new Map([['v', 1]]), new Map([['v', 2]])],
    [new Map([[['v'], 1]]), new Map([[['v'], 2]])],
    [
      new Map([[[1], new Map([[[1], 'one']])]]),
      new Map([[[1], new Map([[[1], 'two']])]]),
    ],
    [Immutable.Map({a: 0}), Immutable.Map({b: 0})],
    [Immutable.Map({v: 1}), Immutable.Map({v: 2})],
    [
      Immutable.OrderedMap()
        .set(1, 'one')
        .set(2, 'two'),
      Immutable.OrderedMap()
        .set(2, 'two')
        .set(1, 'one'),
    ],
    [
      Immutable.Map({1: Immutable.Map({2: {a: 99}})}),
      Immutable.Map({1: Immutable.Map({2: {a: 11}})}),
    ],
    [new Uint8Array([97, 98, 99]), new Uint8Array([97, 98, 100])],
    [{a: 1, b: 2}, jestExpect.objectContaining({a: 2})],
    [false, jestExpect.objectContaining({a: 2})],
    [[1, 3], jestExpect.arrayContaining([1, 2])],
    [1, jestExpect.arrayContaining([1, 2])],
    ['abd', jestExpect.stringContaining('bc')],
    ['abd', jestExpect.stringMatching(/bc/i)],
    [undefined, jestExpect.anything()],
    [undefined, jestExpect.any(Function)],
    [
      'Eve',
      {
        asymmetricMatch: function asymmetricMatch(who) {
          return who === 'Alice' || who === 'Bob';
        },
      },
    ],
    [
      {
        target: {
          nodeType: 1,
          value: 'a',
        },
      },
      {
        target: {
          nodeType: 1,
          value: 'b',
        },
      },
    ],
    [
      {
        nodeName: 'div',
        nodeType: 1,
      },
      {
        nodeName: 'p',
        nodeType: 1,
      },
    ],
    [
      {
        [Symbol.for('foo')]: 1,
        [Symbol.for('bar')]: 2,
      },
      {
        [Symbol.for('foo')]: jestExpect.any(Number),
        [Symbol.for('bar')]: 1,
      },
    ],
  ].forEach(([a, b]) => {
    test(`{pass: false} expect(${stringify(a)}).toEqual(${stringify(
      b,
    )})`, () => {
      expect(() => jestExpect(a).toEqual(b)).toThrowErrorMatchingSnapshot();
      jestExpect(a).not.toEqual(b);
    });
  });

  if (isBigIntDefined) {
    [
      [BigInt(1), BigInt(2)],
      [BigInt(1), 1],
    ].forEach(([a, b]) => {
      test(`{pass: false} expect(${stringify(a)}).toEqual(${stringify(
        b,
      )})`, () => {
        expect(() => jestExpect(a).toEqual(b)).toThrowError('toEqual');
        jestExpect(a).not.toEqual(b);
      });
    });
  }

  [
    [true, true],
    [1, 1],
    [NaN, NaN],
    [0, Number(0)],
    [Number(0), 0],
    [new Number(0), new Number(0)],
    ['abc', 'abc'],
    [String('abc'), 'abc'],
    ['abc', String('abc')],
    [[1], [1]],
    [
      [1, 2],
      [1, 2],
    ],
    [Immutable.List([1]), Immutable.List([1])],
    [Immutable.List([1, 2]), Immutable.List([1, 2])],
    [{}, {}],
    [{a: 99}, {a: 99}],
    [new Set(), new Set()],
    [new Set([1, 2]), new Set([1, 2])],
    [new Set([1, 2]), new Set([2, 1])],
    [new Set([[1], [2]]), new Set([[2], [1]])],
    [
      new Set([new Set([[1]]), new Set([[2]])]),
      new Set([new Set([[2]]), new Set([[1]])]),
    ],
    [new Set([[1], [2], [3], [3]]), new Set([[3], [3], [2], [1]])],
    [new Set([{a: 1}, {b: 2}]), new Set([{b: 2}, {a: 1}])],
    [Immutable.Set(), Immutable.Set()],
    [Immutable.Set([1, 2]), Immutable.Set([1, 2])],
    [Immutable.Set([1, 2]), Immutable.Set([2, 1])],
    [Immutable.OrderedSet(), Immutable.OrderedSet()],
    [Immutable.OrderedSet([1, 2]), Immutable.OrderedSet([1, 2])],
    [new Map(), new Map()],
    [
      new Map([
        [1, 'one'],
        [2, 'two'],
      ]),
      new Map([
        [1, 'one'],
        [2, 'two'],
      ]),
    ],
    [
      new Map([
        [1, 'one'],
        [2, 'two'],
      ]),
      new Map([
        [2, 'two'],
        [1, 'one'],
      ]),
    ],
    [
      new Map([
        [[1], 'one'],
        [[2], 'two'],
        [[3], 'three'],
        [[3], 'four'],
      ]),
      new Map([
        [[3], 'three'],
        [[3], 'four'],
        [[2], 'two'],
        [[1], 'one'],
      ]),
    ],
    [
      new Map([
        [[1], new Map([[[1], 'one']])],
        [[2], new Map([[[2], 'two']])],
      ]),
      new Map([
        [[2], new Map([[[2], 'two']])],
        [[1], new Map([[[1], 'one']])],
      ]),
    ],
    [
      new Map([
        [[1], 'one'],
        [[2], 'two'],
      ]),
      new Map([
        [[2], 'two'],
        [[1], 'one'],
      ]),
    ],
    [
      new Map([
        [{a: 1}, 'one'],
        [{b: 2}, 'two'],
      ]),
      new Map([
        [{b: 2}, 'two'],
        [{a: 1}, 'one'],
      ]),
    ],
    [
      new Map([
        [1, ['one']],
        [2, ['two']],
      ]),
      new Map([
        [2, ['two']],
        [1, ['one']],
      ]),
    ],
    [Immutable.Map(), Immutable.Map()],
    [
      Immutable.Map()
        .set(1, 'one')
        .set(2, 'two'),
      Immutable.Map()
        .set(1, 'one')
        .set(2, 'two'),
    ],
    [
      Immutable.Map()
        .set(1, 'one')
        .set(2, 'two'),
      Immutable.Map()
        .set(2, 'two')
        .set(1, 'one'),
    ],
    [
      Immutable.OrderedMap()
        .set(1, 'one')
        .set(2, 'two'),
      Immutable.OrderedMap()
        .set(1, 'one')
        .set(2, 'two'),
    ],
    [
      Immutable.Map({1: Immutable.Map({2: {a: 99}})}),
      Immutable.Map({1: Immutable.Map({2: {a: 99}})}),
    ],
    [new Uint8Array([97, 98, 99]), new Uint8Array([97, 98, 99])],
    [{a: 1, b: 2}, jestExpect.objectContaining({a: 1})],
    [[1, 2, 3], jestExpect.arrayContaining([2, 3])],
    ['abcd', jestExpect.stringContaining('bc')],
    ['abcd', jestExpect.stringMatching('bc')],
    [true, jestExpect.anything()],
    [() => {}, jestExpect.any(Function)],
    [
      {
        a: 1,
        b: function b() {},
        c: true,
      },
      {
        a: 1,
        b: jestExpect.any(Function),
        c: jestExpect.anything(),
      },
    ],
    [
      'Alice',
      {
        asymmetricMatch: function asymmetricMatch(who) {
          return who === 'Alice' || who === 'Bob';
        },
      },
    ],
    [
      {
        nodeName: 'div',
        nodeType: 1,
      },
      {
        nodeName: 'div',
        nodeType: 1,
      },
    ],
    [
      {
        [Symbol.for('foo')]: 1,
        [Symbol.for('bar')]: 2,
      },
      {
        [Symbol.for('foo')]: jestExpect.any(Number),
        [Symbol.for('bar')]: 2,
      },
    ],
  ].forEach(([a, b]) => {
    test(`{pass: true} expect(${stringify(a)}).not.toEqual(${stringify(
      b,
    )})`, () => {
      jestExpect(a).toEqual(b);
      expect(() => jestExpect(a).not.toEqual(b)).toThrowErrorMatchingSnapshot();
    });
  });

  if (isBigIntDefined) {
    [
      [BigInt(1), BigInt(1)],
      [BigInt(0), BigInt('0')],
      [[BigInt(1)], [BigInt(1)]],
      [
        [BigInt(1), 2],
        [BigInt(1), 2],
      ],
      [Immutable.List([BigInt(1)]), Immutable.List([BigInt(1)])],
      [{a: BigInt(99)}, {a: BigInt(99)}],
      [new Set([BigInt(1), BigInt(2)]), new Set([BigInt(1), BigInt(2)])],
    ].forEach(([a, b]) => {
      test(`{pass: true} expect(${stringify(a)}).not.toEqual(${stringify(
        b,
      )})`, () => {
        jestExpect(a).toEqual(b);
        expect(() => jestExpect(a).not.toEqual(b)).toThrowError('toEqual');
      });
    });
  }

  test('assertion error matcherResult property contains matcher name, expected and actual values', () => {
    const actual = {a: 1};
    const expected = {a: 2};
    try {
      jestExpect(actual).toEqual(expected);
    } catch (error) {
      expect(error.matcherResult).toEqual(
        expect.objectContaining({
          actual,
          expected,
          name: 'toEqual',
        }),
      );
    }
  });

  test('symbol based keys in arrays are processed correctly', () => {
    const mySymbol = Symbol('test');
    const actual1 = [];
    actual1[mySymbol] = 3;
    const actual2 = [];
    actual2[mySymbol] = 4;
    const expected = [];
    expected[mySymbol] = 3;

    expect(actual1).toEqual(expected);
    expect(actual2).not.toEqual(expected);
  });

  test('non-enumerable members should be skipped during equal', () => {
    const actual = {
      x: 3,
    };
    Object.defineProperty(actual, 'test', {
      enumerable: false,
      value: 5,
    });
    expect(actual).toEqual({x: 3});
  });

  test('non-enumerable symbolic members should be skipped during equal', () => {
    const actual = {
      x: 3,
    };
    const mySymbol = Symbol('test');
    Object.defineProperty(actual, mySymbol, {
      enumerable: false,
      value: 5,
    });
    expect(actual).toEqual({x: 3});
  });

  describe('cyclic object equality', () => {
    test('properties with the same circularity are equal', () => {
      const a = {};
      a.x = a;
      const b = {};
      b.x = b;
      expect(a).toEqual(b);
      expect(b).toEqual(a);

      const c = {};
      c.x = a;
      const d = {};
      d.x = b;
      expect(c).toEqual(d);
      expect(d).toEqual(c);
    });

    test('properties with different circularity are not equal', () => {
      const a = {};
      a.x = {y: a};
      const b = {};
      const bx = {};
      b.x = bx;
      bx.y = bx;
      expect(a).not.toEqual(b);
      expect(b).not.toEqual(a);

      const c = {};
      c.x = a;
      const d = {};
      d.x = b;
      expect(c).not.toEqual(d);
      expect(d).not.toEqual(c);
    });

    test('are not equal if circularity is not on the same property', () => {
      const a = {};
      const b = {};
      a.a = a;
      b.a = {};
      b.a.a = a;
      expect(a).not.toEqual(b);
      expect(b).not.toEqual(a);

      const c = {};
      c.x = {x: c};
      const d = {};
      d.x = d;
      expect(c).not.toEqual(d);
      expect(d).not.toEqual(c);
    });
  });
  /* eslint-enable */
});

describe('.toBeInstanceOf()', () => {
  class A {}
  class B {}
  class C extends B {}
  class D extends C {}
  class E extends D {}

  class SubHasStaticNameMethod extends B {
    constructor() {
      super();
    }
    static name() {}
  }

  class HasStaticNameMethod {
    constructor() {}
    static name() {}
  }

  function DefinesNameProp() {}
  Object.defineProperty(DefinesNameProp, 'name', {
    configurable: true,
    enumerable: false,
    value: '',
    writable: true,
  });
  class SubHasNameProp extends DefinesNameProp {}

  [
    [new Map(), Map],
    [[], Array],
    [new A(), A],
    [new C(), B], // C extends B
    [new E(), B], // E extends … extends B
    [new SubHasNameProp(), DefinesNameProp], // omit extends
    [new SubHasStaticNameMethod(), B], // Received
    [new HasStaticNameMethod(), HasStaticNameMethod], // Expected
  ].forEach(([a, b]) => {
    test(`passing ${stringify(a)} and ${stringify(b)}`, () => {
      expect(() =>
        jestExpect(a).not.toBeInstanceOf(b),
      ).toThrowErrorMatchingSnapshot();

      jestExpect(a).toBeInstanceOf(b);
    });
  });

  [
    ['a', String],
    [1, Number],
    [true, Boolean],
    [new A(), B],
    [Object.create(null), A],
    [undefined, String],
    [null, String],
    [/\w+/, function() {}],
    [new DefinesNameProp(), RegExp],
  ].forEach(([a, b]) => {
    test(`failing ${stringify(a)} and ${stringify(b)}`, () => {
      expect(() =>
        jestExpect(a).toBeInstanceOf(b),
      ).toThrowErrorMatchingSnapshot();

      jestExpect(a).not.toBeInstanceOf(b);
    });
  });

  it('throws if constructor is not a function', () => {
    expect(() =>
      jestExpect({}).toBeInstanceOf(4),
    ).toThrowErrorMatchingSnapshot();
  });
});

describe('.toBeTruthy(), .toBeFalsy()', () => {
  it('does not accept arguments', () => {
    expect(() => jestExpect(0).toBeTruthy(null)).toThrowErrorMatchingSnapshot();

    expect(() =>
      jestExpect(0).not.toBeFalsy(null),
    ).toThrowErrorMatchingSnapshot();
  });

  [{}, [], true, 1, 'a', 0.5, new Map(), () => {}, Infinity].forEach(v => {
    test(`'${stringify(v)}' is truthy`, () => {
      jestExpect(v).toBeTruthy();
      jestExpect(v).not.toBeFalsy();

      expect(() =>
        jestExpect(v).not.toBeTruthy(),
      ).toThrowErrorMatchingSnapshot();

      expect(() => jestExpect(v).toBeFalsy()).toThrowErrorMatchingSnapshot();
    });
  });

  if (isBigIntDefined) {
    [BigInt(1)].forEach(v => {
      test(`'${stringify(v)}' is truthy`, () => {
        jestExpect(v).toBeTruthy();
        jestExpect(v).not.toBeFalsy();

        expect(() => jestExpect(v).not.toBeTruthy()).toThrowError('toBeTruthy');

        expect(() => jestExpect(v).toBeFalsy()).toThrowError('toBeFalsy');
      });
    });
  }

  [false, null, NaN, 0, '', undefined].forEach(v => {
    test(`'${stringify(v)}' is falsy`, () => {
      jestExpect(v).toBeFalsy();
      jestExpect(v).not.toBeTruthy();

      expect(() => jestExpect(v).toBeTruthy()).toThrowErrorMatchingSnapshot();

      expect(() =>
        jestExpect(v).not.toBeFalsy(),
      ).toThrowErrorMatchingSnapshot();
    });
  });

  if (isBigIntDefined) {
    [BigInt(0)].forEach(v => {
      test(`'${stringify(v)}' is falsy`, () => {
        jestExpect(v).toBeFalsy();
        jestExpect(v).not.toBeTruthy();

        expect(() => jestExpect(v).toBeTruthy()).toThrowError('toBeTruthy');

        expect(() => jestExpect(v).not.toBeFalsy()).toThrowError('toBeFalsy');
      });
    });
  }
});

describe('.toBeNaN()', () => {
  it('{pass: true} expect(NaN).toBeNaN()', () => {
    [NaN, Math.sqrt(-1), Infinity - Infinity, 0 / 0].forEach(v => {
      jestExpect(v).toBeNaN();

      expect(() => jestExpect(v).not.toBeNaN()).toThrowErrorMatchingSnapshot();
    });
  });

  it('throws', () => {
    [1, '', null, undefined, {}, [], 0.2, 0, Infinity, -Infinity].forEach(v => {
      expect(() => jestExpect(v).toBeNaN()).toThrowErrorMatchingSnapshot();

      jestExpect(v).not.toBeNaN();
    });
  });
});

describe('.toBeNull()', () => {
  [{}, [], true, 1, 'a', 0.5, new Map(), () => {}, Infinity].forEach(v => {
    test(`fails for '${stringify(v)}'`, () => {
      jestExpect(v).not.toBeNull();

      expect(() => jestExpect(v).toBeNull()).toThrowErrorMatchingSnapshot();
    });
  });

  it('fails for null with .not', () => {
    expect(() =>
      jestExpect(null).not.toBeNull(),
    ).toThrowErrorMatchingSnapshot();
  });

  it('pass for null', () => {
    jestExpect(null).toBeNull();
  });
});

describe('.toBeDefined(), .toBeUndefined()', () => {
  [{}, [], true, 1, 'a', 0.5, new Map(), () => {}, Infinity].forEach(v => {
    test(`'${stringify(v)}' is defined`, () => {
      jestExpect(v).toBeDefined();
      jestExpect(v).not.toBeUndefined();

      expect(() =>
        jestExpect(v).not.toBeDefined(),
      ).toThrowErrorMatchingSnapshot();

      expect(() =>
        jestExpect(v).toBeUndefined(),
      ).toThrowErrorMatchingSnapshot();
    });
  });

  if (isBigIntDefined) {
    [BigInt(1)].forEach(v => {
      test(`'${stringify(v)}' is defined`, () => {
        jestExpect(v).toBeDefined();
        jestExpect(v).not.toBeUndefined();

        expect(() => jestExpect(v).not.toBeDefined()).toThrowError(
          'toBeDefined',
        );

        expect(() => jestExpect(v).toBeUndefined()).toThrowError(
          'toBeUndefined',
        );
      });
    });
  }

  test('undefined is undefined', () => {
    jestExpect(undefined).toBeUndefined();
    jestExpect(undefined).not.toBeDefined();

    expect(() =>
      jestExpect(undefined).toBeDefined(),
    ).toThrowErrorMatchingSnapshot();

    expect(() =>
      jestExpect(undefined).not.toBeUndefined(),
    ).toThrowErrorMatchingSnapshot();
  });
});

describe(
  '.toBeGreaterThan(), .toBeLessThan(), ' +
    '.toBeGreaterThanOrEqual(), .toBeLessThanOrEqual()',
  () => {
    [
      [1, 2],
      [-Infinity, Infinity],
      [Number.MIN_VALUE, Number.MAX_VALUE],
      [0x11, 0x22],
      [0b11, 0b111],
      [0o11, 0o22],
      [0.1, 0.2],
    ].forEach(([small, big]) => {
      it(`{pass: true} expect(${small}).toBeLessThan(${big})`, () => {
        jestExpect(small).toBeLessThan(big);
      });

      it(`{pass: false} expect(${big}).toBeLessThan(${small})`, () => {
        jestExpect(big).not.toBeLessThan(small);
      });

      it(`{pass: true} expect(${big}).toBeGreaterThan(${small})`, () => {
        jestExpect(big).toBeGreaterThan(small);
      });

      it(`{pass: false} expect(${small}).toBeGreaterThan(${big})`, () => {
        jestExpect(small).not.toBeGreaterThan(big);
      });

      it(`{pass: true} expect(${small}).toBeLessThanOrEqual(${big})`, () => {
        jestExpect(small).toBeLessThanOrEqual(big);
      });

      it(`{pass: false} expect(${big}).toBeLessThanOrEqual(${small})`, () => {
        jestExpect(big).not.toBeLessThanOrEqual(small);
      });

      it(`{pass: true} expect(${big}).toBeGreaterThanOrEqual(${small})`, () => {
        jestExpect(big).toBeGreaterThanOrEqual(small);
      });

      it(`{pass: false} expect(${small}).toBeGreaterThanOrEqual(${big})`, () => {
        jestExpect(small).not.toBeGreaterThanOrEqual(big);
      });

      it(`throws: [${small}, ${big}]`, () => {
        expect(() =>
          jestExpect(small).toBeGreaterThan(big),
        ).toThrowErrorMatchingSnapshot();

        expect(() =>
          jestExpect(small).not.toBeLessThan(big),
        ).toThrowErrorMatchingSnapshot();

        expect(() =>
          jestExpect(big).not.toBeGreaterThan(small),
        ).toThrowErrorMatchingSnapshot();

        expect(() =>
          jestExpect(big).toBeLessThan(small),
        ).toThrowErrorMatchingSnapshot();

        expect(() =>
          jestExpect(small).toBeGreaterThanOrEqual(big),
        ).toThrowErrorMatchingSnapshot();

        expect(() =>
          jestExpect(small).not.toBeLessThanOrEqual(big),
        ).toThrowErrorMatchingSnapshot();

        expect(() =>
          jestExpect(big).not.toBeGreaterThanOrEqual(small),
        ).toThrowErrorMatchingSnapshot();

        expect(() =>
          jestExpect(big).toBeLessThanOrEqual(small),
        ).toThrowErrorMatchingSnapshot();
      });
    });

    if (isBigIntDefined) {
      test('can compare BigInt to Numbers', () => {
        const a = BigInt(2);
        jestExpect(a).toBeGreaterThan(1);
        jestExpect(a).toBeGreaterThanOrEqual(2);
        jestExpect(2).toBeLessThanOrEqual(a);
        jestExpect(a).toBeLessThan(3);
        jestExpect(a).toBeLessThanOrEqual(2);
      });

      [
        [BigInt(1), BigInt(2)],
        [BigInt(0x11), BigInt(0x22)],
        [-1, BigInt(2)],
      ].forEach(([small, big]) => {
        it(`{pass: true} expect(${stringify(small)}).toBeLessThan(${stringify(
          big,
        )})`, () => {
          jestExpect(small).toBeLessThan(big);
        });

        it(`{pass: false} expect(${stringify(big)}).toBeLessThan(${stringify(
          small,
        )})`, () => {
          jestExpect(big).not.toBeLessThan(small);
        });

        it(`{pass: true} expect(${stringify(big)}).toBeGreaterThan(${stringify(
          small,
        )})`, () => {
          jestExpect(big).toBeGreaterThan(small);
        });

        it(`{pass: false} expect(${stringify(
          small,
        )}).toBeGreaterThan(${stringify(big)})`, () => {
          jestExpect(small).not.toBeGreaterThan(big);
        });

        it(`{pass: true} expect(${stringify(
          small,
        )}).toBeLessThanOrEqual(${stringify(big)})`, () => {
          jestExpect(small).toBeLessThanOrEqual(big);
        });

        it(`{pass: false} expect(${stringify(
          big,
        )}).toBeLessThanOrEqual(${stringify(small)})`, () => {
          jestExpect(big).not.toBeLessThanOrEqual(small);
        });

        it(`{pass: true} expect(${stringify(
          big,
        )}).toBeGreaterThanOrEqual(${stringify(small)})`, () => {
          jestExpect(big).toBeGreaterThanOrEqual(small);
        });

        it(`{pass: false} expect(${stringify(
          small,
        )}).toBeGreaterThanOrEqual(${stringify(big)})`, () => {
          jestExpect(small).not.toBeGreaterThanOrEqual(big);
        });

        it(`throws: [${stringify(small)}, ${stringify(big)}]`, () => {
          expect(() => jestExpect(small).toBeGreaterThan(big)).toThrowError(
            'toBeGreaterThan',
          );

          expect(() => jestExpect(small).not.toBeLessThan(big)).toThrowError(
            'toBeLessThan',
          );

          expect(() => jestExpect(big).not.toBeGreaterThan(small)).toThrowError(
            'toBeGreaterThan',
          );

          expect(() => jestExpect(big).toBeLessThan(small)).toThrowError(
            'toBeLessThan',
          );

          expect(() =>
            jestExpect(small).toBeGreaterThanOrEqual(big),
          ).toThrowError('toBeGreaterThanOrEqual');

          expect(() =>
            jestExpect(small).not.toBeLessThanOrEqual(big),
          ).toThrowError('toBeLessThanOrEqual');

          expect(() =>
            jestExpect(big).not.toBeGreaterThanOrEqual(small),
          ).toThrowError('toBeGreaterThanOrEqual');

          expect(() => jestExpect(big).toBeLessThanOrEqual(small)).toThrowError(
            'toBeLessThanOrEqual',
          );
        });
      });
    }

    [
      [1, 1],
      [Number.MIN_VALUE, Number.MIN_VALUE],
      [Number.MAX_VALUE, Number.MAX_VALUE],
      [Infinity, Infinity],
      [-Infinity, -Infinity],
    ].forEach(([n1, n2]) => {
      test(`equal numbers: [${n1}, ${n2}]`, () => {
        jestExpect(n1).toBeGreaterThanOrEqual(n2);
        jestExpect(n1).toBeLessThanOrEqual(n2);

        expect(() =>
          jestExpect(n1).not.toBeGreaterThanOrEqual(n2),
        ).toThrowErrorMatchingSnapshot();

        expect(() =>
          jestExpect(n1).not.toBeLessThanOrEqual(n2),
        ).toThrowErrorMatchingSnapshot();
      });
    });

    if (isBigIntDefined) {
      [
        [BigInt(1), BigInt(1)],
        [BigInt(Number.MAX_SAFE_INTEGER), BigInt(Number.MAX_SAFE_INTEGER)],
      ].forEach(([n1, n2]) => {
        test(`equal numbers: [${n1}, ${n2}]`, () => {
          jestExpect(n1).toBeGreaterThanOrEqual(n2);
          jestExpect(n1).toBeLessThanOrEqual(n2);

          expect(() =>
            jestExpect(n1).not.toBeGreaterThanOrEqual(n2),
          ).toThrowError('toBeGreaterThanOrEqual');

          expect(() => jestExpect(n1).not.toBeLessThanOrEqual(n2)).toThrowError(
            'toBeLessThanOrEqual',
          );
        });
      });
    }
  },
);

describe('.toContain(), .toContainEqual()', () => {
  const typedArray = new Int8Array(2);
  typedArray[0] = 0;
  typedArray[1] = 1;

  test('iterable', () => {
    // different node versions print iterable differently, so we can't
    // use snapshots here.
    const iterable = {
      *[Symbol.iterator]() {
        yield 1;
        yield 2;
        yield 3;
      },
    };

    jestExpect(iterable).toContain(2);
    jestExpect(iterable).toContainEqual(2);
    expect(() => jestExpect(iterable).not.toContain(1)).toThrowError(
      'toContain',
    );
    expect(() => jestExpect(iterable).not.toContainEqual(1)).toThrowError(
      'toContainEqual',
    );
  });

  [
    [[1, 2, 3, 4], 1],
    [['a', 'b', 'c', 'd'], 'a'],
    [[undefined, null], null],
    [[undefined, null], undefined],
    [[Symbol.for('a')], Symbol.for('a')],
    ['abcdef', 'abc'],
    ['11112111', '2'],
    [new Set(['abc', 'def']), 'abc'],
    [typedArray, 1],
  ].forEach(([list, v]) => {
    it(`'${stringify(list)}' contains '${stringify(v)}'`, () => {
      jestExpect(list).toContain(v);

      expect(() =>
        jestExpect(list).not.toContain(v),
      ).toThrowErrorMatchingSnapshot();
    });
  });

  if (isBigIntDefined) {
    [
      [[BigInt(1), BigInt(2), BigInt(3), BigInt(4)], BigInt(1)],
      [[1, 2, 3, BigInt(3), 4], BigInt(3)],
    ].forEach(([list, v]) => {
      it(`'${stringify(list)}' contains '${stringify(v)}'`, () => {
        jestExpect(list).toContain(v);

        expect(() => jestExpect(list).not.toContain(v)).toThrowError(
          'toContain',
        );
      });
    });
  }

  [
    [[1, 2, 3], 4],
    [[null, undefined], 1],
    [[{}, []], []],
    [[{}, []], {}],
  ].forEach(([list, v]) => {
    it(`'${stringify(list)}' does not contain '${stringify(v)}'`, () => {
      jestExpect(list).not.toContain(v);

      expect(() =>
        jestExpect(list).toContain(v),
      ).toThrowErrorMatchingSnapshot();
    });
  });

  if (isBigIntDefined) {
    [[[BigInt(1), BigInt(2), BigInt(3)], 3]].forEach(([list, v]) => {
      it(`'${stringify(list)}' does not contain '${stringify(v)}'`, () => {
        jestExpect(list).not.toContain(v);

        expect(() => jestExpect(list).toContain(v)).toThrowError('toContain');
      });
    });
  }

  test('error cases', () => {
    expect(() => jestExpect(null).toContain(1)).toThrowErrorMatchingSnapshot();
  });

  [
    [[1, 2, 3, 4], 1],
    [['a', 'b', 'c', 'd'], 'a'],
    [[undefined, null], null],
    [[undefined, null], undefined],
    [[Symbol.for('a')], Symbol.for('a')],
    [[{a: 'b'}, {a: 'c'}], {a: 'b'}],
    [new Set([1, 2, 3, 4]), 1],
    [typedArray, 1],
  ].forEach(([list, v]) => {
    it(`'${stringify(list)}' contains a value equal to '${stringify(
      v,
    )}'`, () => {
      jestExpect(list).toContainEqual(v);
      expect(() =>
        jestExpect(list).not.toContainEqual(v),
      ).toThrowErrorMatchingSnapshot();
    });
  });

  [[[{a: 'b'}, {a: 'c'}], {a: 'd'}]].forEach(([list, v]) => {
    it(`'${stringify(list)}' does not contain a value equal to'${stringify(
      v,
    )}'`, () => {
      jestExpect(list).not.toContainEqual(v);

      expect(() =>
        jestExpect(list).toContainEqual(v),
      ).toThrowErrorMatchingSnapshot();
    });
  });

  test('error cases for toContainEqual', () => {
    expect(() =>
      jestExpect(null).toContainEqual(1),
    ).toThrowErrorMatchingSnapshot();
  });
});

describe('.toBeCloseTo', () => {
  [
    [0, 0],
    [0, 0.001],
    [1.23, 1.229],
    [1.23, 1.226],
    [1.23, 1.225],
    [1.23, 1.234],
    [Infinity, Infinity],
    [-Infinity, -Infinity],
  ].forEach(([n1, n2]) => {
    it(`{pass: true} expect(${n1}).toBeCloseTo(${n2})`, () => {
      jestExpect(n1).toBeCloseTo(n2);

      expect(() =>
        jestExpect(n1).not.toBeCloseTo(n2),
      ).toThrowErrorMatchingSnapshot();
    });
  });

  [
    [0, 0.01],
    [1, 1.23],
    [1.23, 1.2249999],
    [Infinity, -Infinity],
    [Infinity, 1.23],
    [-Infinity, -1.23],
  ].forEach(([n1, n2]) => {
    it(`{pass: false} expect(${n1}).toBeCloseTo(${n2})`, () => {
      jestExpect(n1).not.toBeCloseTo(n2);

      expect(() =>
        jestExpect(n1).toBeCloseTo(n2),
      ).toThrowErrorMatchingSnapshot();
    });
  });

  [
    [3.141592e-7, 3e-7, 8],
    [56789, 51234, -4],
  ].forEach(([n1, n2, p]) => {
    it(`{pass: false} expect(${n1}).toBeCloseTo(${n2}, ${p})`, () => {
      jestExpect(n1).not.toBeCloseTo(n2, p);

      expect(() =>
        jestExpect(n1).toBeCloseTo(n2, p),
      ).toThrowErrorMatchingSnapshot();
    });
  });

  [
    [0, 0.1, 0],
    [0, 0.0001, 3],
    [0, 0.000004, 5],
    [2.0000002, 2, 5],
  ].forEach(([n1, n2, p]) => {
    it(`{pass: true} expect(${n1}).toBeCloseTo(${n2}, ${p})`, () => {
      jestExpect(n1).toBeCloseTo(n2, p);

      expect(() =>
        jestExpect(n1).not.toBeCloseTo(n2, p),
      ).toThrowErrorMatchingSnapshot();
    });
  });

  describe('throws: Matcher error', () => {
    test('promise empty isNot false received', () => {
      const precision = 3;
      const expected = 0;
      const received = '';
      expect(() => {
        jestExpect(received).toBeCloseTo(expected, precision);
      }).toThrowErrorMatchingSnapshot();
    });

    test('promise empty isNot true expected', () => {
      const received = 0.1;
      // expected is undefined
      expect(() => {
        jestExpect(received).not.toBeCloseTo();
      }).toThrowErrorMatchingSnapshot();
    });

    test('promise rejects isNot false expected', () => {
      const expected = '0';
      const received = Promise.reject(0.01);
      return expect(
        jestExpect(received).rejects.toBeCloseTo(expected),
      ).rejects.toThrowErrorMatchingSnapshot();
    });

    test('promise rejects isNot true received', () => {
      const expected = 0;
      const received = Promise.reject(Symbol('0.1'));
      return expect(
        jestExpect(received).rejects.not.toBeCloseTo(expected),
      ).rejects.toThrowErrorMatchingSnapshot();
    });

    test('promise resolves isNot false received', () => {
      const precision = 3;
      const expected = 0;
      const received = Promise.resolve(false);
      return expect(
        jestExpect(received).resolves.toBeCloseTo(expected, precision),
      ).rejects.toThrowErrorMatchingSnapshot();
    });

    test('promise resolves isNot true expected', () => {
      const precision = 3;
      const expected = null;
      const received = Promise.resolve(0.1);
      return expect(
        jestExpect(received).resolves.not.toBeCloseTo(expected, precision),
      ).rejects.toThrowErrorMatchingSnapshot();
    });
  });
});

describe('.toMatch()', () => {
  [
    ['foo', 'foo'],
    ['Foo bar', /^foo/i],
  ].forEach(([n1, n2]) => {
    it(`{pass: true} expect(${n1}).toMatch(${n2})`, () => {
      jestExpect(n1).toMatch(n2);

      expect(() =>
        jestExpect(n1).not.toMatch(n2),
      ).toThrowErrorMatchingSnapshot();
    });
  });

  [
    ['bar', 'foo'],
    ['bar', /foo/],
  ].forEach(([n1, n2]) => {
    it(`throws: [${n1}, ${n2}]`, () => {
      expect(() => jestExpect(n1).toMatch(n2)).toThrowErrorMatchingSnapshot();
    });
  });

  [
    [1, 'foo'],
    [{}, 'foo'],
    [[], 'foo'],
    [true, 'foo'],
    [/foo/i, 'foo'],
    [() => {}, 'foo'],
    [undefined, 'foo'],
  ].forEach(([n1, n2]) => {
    it(
      'throws if non String actual value passed:' +
        ` [${stringify(n1)}, ${stringify(n2)}]`,
      () => {
        expect(() => jestExpect(n1).toMatch(n2)).toThrowErrorMatchingSnapshot();
      },
    );
  });

  [
    ['foo', 1],
    ['foo', {}],
    ['foo', []],
    ['foo', true],
    ['foo', () => {}],
    ['foo', undefined],
  ].forEach(([n1, n2]) => {
    it(
      `throws if non String/RegExp expected value passed:` +
        ` [${stringify(n1)}, ${stringify(n2)}]`,
      () => {
        expect(() => jestExpect(n1).toMatch(n2)).toThrowErrorMatchingSnapshot();
      },
    );
  });

  it('escapes strings properly', () => {
    jestExpect('this?: throws').toMatch('this?: throws');
  });

  it('does not maintain RegExp state between calls', () => {
    const regex = /[f]\d+/gi;
    jestExpect('f123').toMatch(regex);
    jestExpect('F456').toMatch(regex);
    jestExpect(regex.lastIndex).toBe(0);
  });
});

describe('.toHaveLength', () => {
  [
    [[1, 2], 2],
    [[], 0],
    [['a', 'b'], 2],
    ['abc', 3],
    ['', 0],
  ].forEach(([received, length]) => {
    test(`{pass: true} expect(${stringify(
      received,
    )}).toHaveLength(${length})`, () => {
      jestExpect(received).toHaveLength(length);
      expect(() =>
        jestExpect(received).not.toHaveLength(length),
      ).toThrowErrorMatchingSnapshot();
    });
  });

  [
    [[1, 2], 3],
    [[], 1],
    [['a', 'b'], 99],
    ['abc', 66],
    ['', 1],
  ].forEach(([received, length]) => {
    test(`{pass: false} expect(${stringify(
      received,
    )}).toHaveLength(${length})`, () => {
      jestExpect(received).not.toHaveLength(length);
      expect(() =>
        jestExpect(received).toHaveLength(length),
      ).toThrowErrorMatchingSnapshot();
    });
  });

  test('error cases', () => {
    expect(() =>
      jestExpect({a: 9}).toHaveLength(1),
    ).toThrowErrorMatchingSnapshot();
    expect(() => jestExpect(0).toHaveLength(1)).toThrowErrorMatchingSnapshot();
    expect(() =>
      jestExpect(undefined).not.toHaveLength(1),
    ).toThrowErrorMatchingSnapshot();
  });

  describe('matcher error expected length', () => {
    test('not number', () => {
      const expected = '3';
      const received = 'abc';
      expect(() => {
        jestExpect(received).not.toHaveLength(expected);
      }).toThrowErrorMatchingSnapshot();
    });

    test('number Infinity', () => {
      const expected = Infinity;
      const received = Promise.reject('abc');
      return expect(
        jestExpect(received).rejects.toHaveLength(expected),
      ).rejects.toThrowErrorMatchingSnapshot();
    });

    test('number NaN', () => {
      const expected = NaN;
      const received = Promise.reject('abc');
      return expect(
        jestExpect(received).rejects.not.toHaveLength(expected),
      ).rejects.toThrowErrorMatchingSnapshot();
    });

    test('number float', () => {
      const expected = 0.5;
      const received = Promise.resolve('abc');
      return expect(
        jestExpect(received).resolves.toHaveLength(expected),
      ).rejects.toThrowErrorMatchingSnapshot();
    });

    test('number negative integer', () => {
      const expected = -3;
      const received = Promise.resolve('abc');
      return expect(
        jestExpect(received).resolves.not.toHaveLength(expected),
      ).rejects.toThrowErrorMatchingSnapshot();
    });
  });
});

describe('.toHaveProperty()', () => {
  class Foo {
    get a() {
      return undefined;
    }
    get b() {
      return 'b';
    }
    set setter(val) {
      this.val = val;
    }
  }

  class Foo2 extends Foo {
    get c() {
      return 'c';
    }
  }
  const foo2 = new Foo2();
  foo2.setter = true;

  function E(nodeName) {
    this.nodeName = nodeName.toUpperCase();
  }
  E.prototype.nodeType = 1;

  const memoized = function() {};
  memoized.memo = [];

  const pathDiff = ['children', 0];

  const receivedDiffSingle = {
    children: ['"That cartoon"'],
    props: null,
    type: 'p',
  };
  const valueDiffSingle = '"That cat cartoon"';

  const receivedDiffMultiple = {
    children: [
      'Roses are red.\nViolets are blue.\nTesting with Jest is good for you.',
    ],
    props: null,
    type: 'pre',
  };
  const valueDiffMultiple =
    'Roses are red, violets are blue.\nTesting with Jest\nIs good for you.';

  [
    [{a: {b: {c: {d: 1}}}}, 'a.b.c.d', 1],
    [{a: {b: {c: {d: 1}}}}, ['a', 'b', 'c', 'd'], 1],
    [{'a.b.c.d': 1}, ['a.b.c.d'], 1],
    [{a: {b: [1, 2, 3]}}, ['a', 'b', 1], 2],
    [{a: {b: [1, 2, 3]}}, ['a', 'b', 1], expect.any(Number)],
    [{a: 0}, 'a', 0],
    [{a: {b: undefined}}, 'a.b', undefined],
    [{a: {}}, 'a.b', undefined], // delete for breaking change in future major
    [{a: {b: {c: 5}}}, 'a.b', {c: 5}],
    [Object.assign(Object.create(null), {property: 1}), 'property', 1],
    [new Foo(), 'a', undefined],
    [new Foo(), 'b', 'b'],
    [new Foo(), 'setter', undefined],
    [foo2, 'a', undefined],
    [foo2, 'c', 'c'],
    [foo2, 'val', true],
    [new E('div'), 'nodeType', 1],
    ['', 'length', 0],
    [memoized, 'memo', []],
  ].forEach(([obj, keyPath, value]) => {
    test(`{pass: true} expect(${stringify(
      obj,
    )}).toHaveProperty('${keyPath}', ${stringify(value)})`, () => {
      jestExpect(obj).toHaveProperty(keyPath, value);
      expect(() =>
        jestExpect(obj).not.toHaveProperty(keyPath, value),
      ).toThrowErrorMatchingSnapshot();
    });
  });

  [
    [{a: {b: {c: {d: 1}}}}, 'a.b.ttt.d', 1],
    [{a: {b: {c: {d: 1}}}}, 'a.b.c.d', 2],
    [{'a.b.c.d': 1}, 'a.b.c.d', 2],
    [{'a.b.c.d': 1}, ['a.b.c.d'], 2],
    [receivedDiffSingle, pathDiff, valueDiffSingle],
    [receivedDiffMultiple, pathDiff, valueDiffMultiple],
    [{a: {b: {c: {d: 1}}}}, ['a', 'b', 'c', 'd'], 2],
    [{a: {b: {c: {}}}}, 'a.b.c.d', 1],
    [{a: 1}, 'a.b.c.d', 5],
    [{}, 'a', 'test'],
    [{a: {b: 3}}, 'a.b', undefined],
    [1, 'a.b.c', 'test'],
    ['abc', 'a.b.c', {a: 5}],
    [{a: {b: {c: 5}}}, 'a.b', {c: 4}],
    [new Foo(), 'a', 'a'],
    [new Foo(), 'b', undefined],
    // [{a: {}}, 'a.b', undefined], // add for breaking change in future major
  ].forEach(([obj, keyPath, value]) => {
    test(`{pass: false} expect(${stringify(
      obj,
    )}).toHaveProperty('${keyPath}', ${stringify(value)})`, () => {
      expect(() =>
        jestExpect(obj).toHaveProperty(keyPath, value),
      ).toThrowErrorMatchingSnapshot();
      jestExpect(obj).not.toHaveProperty(keyPath, value);
    });
  });

  [
    [{a: {b: {c: {d: 1}}}}, 'a.b.c.d'],
    [{a: {b: {c: {d: 1}}}}, ['a', 'b', 'c', 'd']],
    [{'a.b.c.d': 1}, ['a.b.c.d']],
    [{a: {b: [1, 2, 3]}}, ['a', 'b', 1]],
    [{a: 0}, 'a'],
    [{a: {b: undefined}}, 'a.b'],
  ].forEach(([obj, keyPath]) => {
    test(`{pass: true} expect(${stringify(
      obj,
    )}).toHaveProperty('${keyPath}')`, () => {
      jestExpect(obj).toHaveProperty(keyPath);
      expect(() =>
        jestExpect(obj).not.toHaveProperty(keyPath),
      ).toThrowErrorMatchingSnapshot();
    });
  });

  [
    [{a: {b: {c: {}}}}, 'a.b.c.d'],
    [{a: 1}, 'a.b.c.d'],
    [{}, 'a'],
    [1, 'a.b.c'],
    ['abc', 'a.b.c'],
    [false, 'key'],
    [0, 'key'],
    ['', 'key'],
    [Symbol(), 'key'],
    [Object.assign(Object.create(null), {key: 1}), 'not'],
  ].forEach(([obj, keyPath]) => {
    test(`{pass: false} expect(${stringify(
      obj,
    )}).toHaveProperty('${keyPath}')`, () => {
      expect(() =>
        jestExpect(obj).toHaveProperty(keyPath),
      ).toThrowErrorMatchingSnapshot();
      jestExpect(obj).not.toHaveProperty(keyPath);
    });
  });

  [
    [null, 'a.b'],
    [undefined, 'a'],
    [{a: {b: {}}}, undefined],
    [{a: {b: {}}}, null],
    [{a: {b: {}}}, 1],
    [{}, []], // Residue: pass must be initialized
  ].forEach(([obj, keyPath]) => {
    test(`{error} expect(${stringify(
      obj,
    )}).toHaveProperty('${keyPath}')`, () => {
      expect(() =>
        jestExpect(obj).toHaveProperty(keyPath),
      ).toThrowErrorMatchingSnapshot();
    });
  });
});

describe('toMatchObject()', () => {
  class Foo {
    get a() {
      return undefined;
    }
    get b() {
      return 'b';
    }
  }

  const testNotToMatchSnapshots = tuples => {
    tuples.forEach(([n1, n2]) => {
      it(`{pass: true} expect(${stringify(n1)}).toMatchObject(${stringify(
        n2,
      )})`, () => {
        jestExpect(n1).toMatchObject(n2);
        expect(() =>
          jestExpect(n1).not.toMatchObject(n2),
        ).toThrowErrorMatchingSnapshot();
      });
    });
  };

  const testToMatchSnapshots = tuples => {
    tuples.forEach(([n1, n2]) => {
      it(`{pass: false} expect(${stringify(n1)}).toMatchObject(${stringify(
        n2,
      )})`, () => {
        jestExpect(n1).not.toMatchObject(n2);
        expect(() =>
          jestExpect(n1).toMatchObject(n2),
        ).toThrowErrorMatchingSnapshot();
      });
    });
  };

  describe('circular references', () => {
    describe('simple circular references', () => {
      const circularObjA1 = {a: 'hello'};
      circularObjA1.ref = circularObjA1;

      const circularObjB = {a: 'world'};
      circularObjB.ref = circularObjB;

      const circularObjA2 = {a: 'hello'};
      circularObjA2.ref = circularObjA2;

      const primitiveInsteadOfRef = {};
      primitiveInsteadOfRef.ref = 'not a ref';

      testNotToMatchSnapshots([
        [circularObjA1, {}],
        [circularObjA2, circularObjA1],
      ]);

      testToMatchSnapshots([
        [{}, circularObjA1],
        [circularObjA1, circularObjB],
        [primitiveInsteadOfRef, circularObjA1],
      ]);
    });

    describe('transitive circular references', () => {
      const transitiveCircularObjA1 = {a: 'hello'};
      transitiveCircularObjA1.nestedObj = {parentObj: transitiveCircularObjA1};

      const transitiveCircularObjA2 = {a: 'hello'};
      transitiveCircularObjA2.nestedObj = {
        parentObj: transitiveCircularObjA2,
      };

      const transitiveCircularObjB = {a: 'world'};
      transitiveCircularObjB.nestedObj = {
        parentObj: transitiveCircularObjB,
      };

      const primitiveInsteadOfRef = {};
      primitiveInsteadOfRef.nestedObj = {
        parentObj: 'not the parent ref',
      };

      testNotToMatchSnapshots([
        [transitiveCircularObjA1, {}],
        [transitiveCircularObjA2, transitiveCircularObjA1],
      ]);

      testToMatchSnapshots([
        [{}, transitiveCircularObjA1],
        [transitiveCircularObjB, transitiveCircularObjA1],
        [primitiveInsteadOfRef, transitiveCircularObjA1],
      ]);
    });
  });

  testNotToMatchSnapshots([
    [{a: 'b', c: 'd'}, {a: 'b'}],
    [
      {a: 'b', c: 'd'},
      {a: 'b', c: 'd'},
    ],
    [
      {a: 'b', t: {x: {r: 'r'}, z: 'z'}},
      {a: 'b', t: {z: 'z'}},
    ],
    [{a: 'b', t: {x: {r: 'r'}, z: 'z'}}, {t: {x: {r: 'r'}}}],
    [{a: [3, 4, 5], b: 'b'}, {a: [3, 4, 5]}],
    [{a: [3, 4, 5, 'v'], b: 'b'}, {a: [3, 4, 5, 'v']}],
    [{a: 1, c: 2}, {a: jestExpect.any(Number)}],
    [{a: {x: 'x', y: 'y'}}, {a: {x: jestExpect.any(String)}}],
    [new Set([1, 2]), new Set([1, 2])],
    [new Set([1, 2]), new Set([2, 1])],
    [new Date('2015-11-30'), new Date('2015-11-30')],
    [{a: new Date('2015-11-30'), b: 'b'}, {a: new Date('2015-11-30')}],
    [{a: null, b: 'b'}, {a: null}],
    [{a: undefined, b: 'b'}, {a: undefined}],
    [{a: [{a: 'a', b: 'b'}]}, {a: [{a: 'a'}]}],
    [
      [1, 2],
      [1, 2],
    ],
    [{a: undefined}, {a: undefined}],
    [[], []],
    [new Error('foo'), new Error('foo')],
    [new Error('bar'), {message: 'bar'}],
    [new Foo(), {a: undefined, b: 'b'}],
    [Object.assign(Object.create(null), {a: 'b'}), {a: 'b'}],
    [
      {a: 'b', c: 'd', [Symbol.for('jest')]: 'jest'},
      {a: 'b', [Symbol.for('jest')]: 'jest'},
    ],
    [
      {a: 'b', c: 'd', [Symbol.for('jest')]: 'jest'},
      {a: 'b', c: 'd', [Symbol.for('jest')]: 'jest'},
    ],
  ]);

  testToMatchSnapshots([
    [{a: 'b', c: 'd'}, {e: 'b'}],
    [
      {a: 'b', c: 'd'},
      {a: 'b!', c: 'd'},
    ],
    [{a: 'a', c: 'd'}, {a: jestExpect.any(Number)}],
    [
      {a: 'b', t: {x: {r: 'r'}, z: 'z'}},
      {a: 'b', t: {z: [3]}},
    ],
    [{a: 'b', t: {x: {r: 'r'}, z: 'z'}}, {t: {l: {r: 'r'}}}],
    [{a: [3, 4, 5], b: 'b'}, {a: [3, 4, 5, 6]}],
    [{a: [3, 4, 5], b: 'b'}, {a: [3, 4]}],
    [{a: [3, 4, 'v'], b: 'b'}, {a: ['v']}],
    [{a: [3, 4, 5], b: 'b'}, {a: {b: 4}}],
    [{a: [3, 4, 5], b: 'b'}, {a: {b: jestExpect.any(String)}}],
    [
      [1, 2],
      [1, 3],
    ],
    [[0], [-0]],
    [new Set([1, 2]), new Set([2])],
    [new Date('2015-11-30'), new Date('2015-10-10')],
    [{a: new Date('2015-11-30'), b: 'b'}, {a: new Date('2015-10-10')}],
    [{a: null, b: 'b'}, {a: '4'}],
    [{a: null, b: 'b'}, {a: undefined}],
    [{a: undefined}, {a: null}],
    [{a: [{a: 'a', b: 'b'}]}, {a: [{a: 'c'}]}],
    [{a: 1, b: 1, c: 1, d: {e: {f: 555}}}, {d: {e: {f: 222}}}],
    [{}, {a: undefined}],
    [
      [1, 2, 3],
      [2, 3, 1],
    ],
    [
      [1, 2, 3],
      [1, 2, 2],
    ],
    [new Error('foo'), new Error('bar')],
    [Object.assign(Object.create(null), {a: 'b'}), {c: 'd'}],
    [
      {a: 'b', c: 'd', [Symbol.for('jest')]: 'jest'},
      {a: 'c', [Symbol.for('jest')]: expect.any(String)},
    ],
  ]);

  [
    [null, {}],
    [4, {}],
    ['44', {}],
    [true, {}],
    [undefined, {}],
    [{}, null],
    [{}, 4],
    [{}, 'some string'],
    [{}, true],
    [{}, undefined],
  ].forEach(([n1, n2]) => {
    it(`throws expect(${stringify(n1)}).toMatchObject(${stringify(
      n2,
    )})`, () => {
      expect(() =>
        jestExpect(n1).toMatchObject(n2),
      ).toThrowErrorMatchingSnapshot();
    });
  });

  it('does not match properties up in the prototype chain', () => {
    const a = {};
    a.ref = a;

    const b = Object.create(a);
    b.other = 'child';

    const matcher = {other: 'child'};
    matcher.ref = matcher;

    jestExpect(b).not.toMatchObject(matcher);
    expect(() =>
      jestExpect(b).toMatchObject(matcher),
    ).toThrowErrorMatchingSnapshot();
  });
});