比较详情

\Comparison details

• 使用 Object.is() 比较原始值。

  \Primitive values are compared using Object.is().

• 对象的 类型标签 应该是相同的。

  \Type tags of objects should be the same.

• 使用 === 操作符 比较对象的 [[Prototype]]。

  \[[Prototype]] of objects are compared using the === operator.

• 仅考虑 可枚举的 "自有" 属性。

  \Only enumerable "own" properties are considered.

• Error 名称和消息总是被比较,即使它们不是可枚举的属性。

  \Error names and messages are always compared, even if these are not enumerable properties.

• 也比较了可枚举的自有 Symbol 属性。

  \Enumerable own Symbol properties are compared as well.

• 对象封装器 作为对象和展开的值进行比较。

  \Object wrappers are compared both as objects and unwrapped values.

• Object 属性是无序比较的。

  \Object properties are compared unordered.

• Map 键和 Set 项是无序比较的。

  \Map keys and Set items are compared unordered.

• 当双方不同或双方遇到循环引用时,则递归停止。

  \Recursion stops when both sides differ or both sides encounter a circular reference.

• WeakMap 和 WeakSet 的比较不依赖于它们的值。有关更多详细信息,请参见下文。

  \WeakMap and WeakSet comparison does not rely on their values. See below for further details.

import assert from 'node:assert/strict';
// This fails because 1 !== '1'.
assert.deepStrictEqual({ a: 1 }, { a: '1' });
// AssertionError: Expected inputs to be strictly deep-equal:
// + actual - expected
//
// {
// + a: 1
// - a: '1'
// }
// The following objects don't have own properties
const date = new Date();
const object = {};
const fakeDate = {};
Object.setPrototypeOf(fakeDate, Date.prototype);
// Different [[Prototype]]:
assert.deepStrictEqual(object, fakeDate);
// AssertionError: Expected inputs to be strictly deep-equal:
// + actual - expected
//
// + {}
// - Date {}
// Different type tags:
assert.deepStrictEqual(date, fakeDate);
// AssertionError: Expected inputs to be strictly deep-equal:
// + actual - expected
//
// + 2018年04月26日T00:49:08.604Z
// - Date {}
assert.deepStrictEqual(NaN, NaN);
// OK because Object.is(NaN, NaN) is true.
// Different unwrapped numbers:
assert.deepStrictEqual(new Number(1), new Number(2));
// AssertionError: Expected inputs to be strictly deep-equal:
// + actual - expected
//
// + [Number: 1]
// - [Number: 2]
assert.deepStrictEqual(new String('foo'), Object('foo'));
// OK because the object and the string are identical when unwrapped.
assert.deepStrictEqual(-0, -0);
// OK
// Different zeros:
assert.deepStrictEqual(0, -0);
// AssertionError: Expected inputs to be strictly deep-equal:
// + actual - expected
//
// + 0
// - -0
const symbol1 = Symbol();
const symbol2 = Symbol();
assert.deepStrictEqual({ [symbol1]: 1 }, { [symbol1]: 1 });
// OK, because it is the same symbol on both objects.
assert.deepStrictEqual({ [symbol1]: 1 }, { [symbol2]: 1 });
// AssertionError [ERR_ASSERTION]: Inputs identical but not reference equal:
//
// {
// [Symbol()]: 1
// }
const weakMap1 = new WeakMap();
const weakMap2 = new WeakMap([[{}, {}]]);
const weakMap3 = new WeakMap();
weakMap3.unequal = true;
assert.deepStrictEqual(weakMap1, weakMap2);
// OK, because it is impossible to compare the entries
// Fails because weakMap3 has a property that weakMap1 does not contain:
assert.deepStrictEqual(weakMap1, weakMap3);
// AssertionError: Expected inputs to be strictly deep-equal:
// + actual - expected
//
// WeakMap {
// + [items unknown]
// - [items unknown],
// - unequal: true
// }const assert = require('node:assert/strict');
// This fails because 1 !== '1'.
assert.deepStrictEqual({ a: 1 }, { a: '1' });
// AssertionError: Expected inputs to be strictly deep-equal:
// + actual - expected
//
// {
// + a: 1
// - a: '1'
// }
// The following objects don't have own properties
const date = new Date();
const object = {};
const fakeDate = {};
Object.setPrototypeOf(fakeDate, Date.prototype);
// Different [[Prototype]]:
assert.deepStrictEqual(object, fakeDate);
// AssertionError: Expected inputs to be strictly deep-equal:
// + actual - expected
//
// + {}
// - Date {}
// Different type tags:
assert.deepStrictEqual(date, fakeDate);
// AssertionError: Expected inputs to be strictly deep-equal:
// + actual - expected
//
// + 2018年04月26日T00:49:08.604Z
// - Date {}
assert.deepStrictEqual(NaN, NaN);
// OK because Object.is(NaN, NaN) is true.
// Different unwrapped numbers:
assert.deepStrictEqual(new Number(1), new Number(2));
// AssertionError: Expected inputs to be strictly deep-equal:
// + actual - expected
//
// + [Number: 1]
// - [Number: 2]
assert.deepStrictEqual(new String('foo'), Object('foo'));
// OK because the object and the string are identical when unwrapped.
assert.deepStrictEqual(-0, -0);
// OK
// Different zeros:
assert.deepStrictEqual(0, -0);
// AssertionError: Expected inputs to be strictly deep-equal:
// + actual - expected
//
// + 0
// - -0
const symbol1 = Symbol();
const symbol2 = Symbol();
assert.deepStrictEqual({ [symbol1]: 1 }, { [symbol1]: 1 });
// OK, because it is the same symbol on both objects.
assert.deepStrictEqual({ [symbol1]: 1 }, { [symbol2]: 1 });
// AssertionError [ERR_ASSERTION]: Inputs identical but not reference equal:
//
// {
// [Symbol()]: 1
// }
const weakMap1 = new WeakMap();
const weakMap2 = new WeakMap([[{}, {}]]);
const weakMap3 = new WeakMap();
weakMap3.unequal = true;
assert.deepStrictEqual(weakMap1, weakMap2);
// OK, because it is impossible to compare the entries
// Fails because weakMap3 has a property that weakMap1 does not contain:
assert.deepStrictEqual(weakMap1, weakMap3);
// AssertionError: Expected inputs to be strictly deep-equal:
// + actual - expected
//
// WeakMap {
// + [items unknown]
// - [items unknown],
// - unequal: true
// }拷贝

如果值不相等,则抛出 AssertionError,其 message 属性设置为等于 message 参数的值。如果未定义 message 参数,则分配默认错误消息。如果 message 参数是 Error 的实例,则将抛出错误而不是 AssertionError。

\If the values are not equal, an AssertionError is thrown with a message property set equal to the value of the message parameter. If the message parameter is undefined, a default error message is assigned. If the message parameter is an instance of an Error then it will be thrown instead of the AssertionError.