Node.js v25.0.0 文件

嚴格斷言模式#

在嚴格斷言模式下，非嚴格方法的行為與其對應的嚴格方法類似。例如，assert.deepEqual() 的行為將類似於 assert.deepStrictEqual()。

在嚴格斷言模式下，物件的錯誤訊息會顯示差異（diff）。在舊式斷言模式下，物件的錯誤訊息會顯示物件本身，且常常被截斷。

要使用嚴格斷言模式

import { strict as assert } from 'node:assert';const assert = require('node:assert').strict;copy

import assert from 'node:assert/strict';const assert = require('node:assert/strict');copy

錯誤差異示例

import { strict as assert } from 'node:assert';

assert.deepEqual([[[1, 2, 3]], 4, 5], [[[1, 2, '3']], 4, 5]);
// AssertionError: Expected inputs to be strictly deep-equal:
// + actual - expected ... Lines skipped
//
//   [
//     [
// ...
//       2,
// +     3
// -     '3'
//     ],
// ...
//     5
//   ]const assert = require('node:assert/strict');

assert.deepEqual([[[1, 2, 3]], 4, 5], [[[1, 2, '3']], 4, 5]);
// AssertionError: Expected inputs to be strictly deep-equal:
// + actual - expected ... Lines skipped
//
//   [
//     [
// ...
//       2,
// +     3
// -     '3'
//     ],
// ...
//     5
//   ]copy

要停用顏色，請使用 NO_COLOR 或 NODE_DISABLE_COLORS 環境變數。這也會停用 REPL 中的顏色。有關終端環境中顏色支援的更多資訊，請閱讀 tty getColorDepth() 文件。

舊式斷言模式#

舊式斷言模式在以下函式中使用== 運算子：

• assert.deepEqual()
• assert.equal()
• assert.notDeepEqual()
• assert.notEqual()

要使用舊式斷言模式

import assert from 'node:assert';const assert = require('node:assert');copy

舊式斷言模式可能會產生令人意外的結果，尤其是在使用 assert.deepEqual() 時。

// WARNING: This does not throw an AssertionError in legacy assertion mode!
assert.deepEqual(/a/gi, new Date()); copy

類: assert.AssertionError#

• 繼承自：<errors.Error>

表示斷言失敗。所有由 node:assert 模組丟擲的錯誤都將是 AssertionError 類的例項。

import assert from 'node:assert';

// Generate an AssertionError to compare the error message later:
const { message } = new assert.AssertionError({
  actual: 1,
  expected: 2,
  operator: 'strictEqual',
});

// Verify error output:
try {
  assert.strictEqual(1, 2);
} catch (err) {
  assert(err instanceof assert.AssertionError);
  assert.strictEqual(err.message, message);
  assert.strictEqual(err.name, 'AssertionError');
  assert.strictEqual(err.actual, 1);
  assert.strictEqual(err.expected, 2);
  assert.strictEqual(err.code, 'ERR_ASSERTION');
  assert.strictEqual(err.operator, 'strictEqual');
  assert.strictEqual(err.generatedMessage, true);
}const assert = require('node:assert');

// Generate an AssertionError to compare the error message later:
const { message } = new assert.AssertionError({
  actual: 1,
  expected: 2,
  operator: 'strictEqual',
});

// Verify error output:
try {
  assert.strictEqual(1, 2);
} catch (err) {
  assert(err instanceof assert.AssertionError);
  assert.strictEqual(err.message, message);
  assert.strictEqual(err.name, 'AssertionError');
  assert.strictEqual(err.actual, 1);
  assert.strictEqual(err.expected, 2);
  assert.strictEqual(err.code, 'ERR_ASSERTION');
  assert.strictEqual(err.operator, 'strictEqual');
  assert.strictEqual(err.generatedMessage, true);
}copy

類: assert.Assert#

Assert 類允許建立具有自定義選項的獨立斷言例項。

const { Assert } = require('node:assert');
const assertInstance = new Assert({ diff: 'full' });
assertInstance.deepStrictEqual({ a: 1 }, { a: 2 });
// Shows a full diff in the error message. copy

const myAssert = new Assert({ diff: 'full' });

// This works as expected - uses 'full' diff
myAssert.strictEqual({ a: 1 }, { b: { c: 1 } });

// This loses the 'full' diff setting - falls back to default 'simple' diff
const { strictEqual } = myAssert;
strictEqual({ a: 1 }, { b: { c: 1 } }); copy

class Foo {
  constructor(a) {
    this.a = a;
  }
}

class Bar {
  constructor(a) {
    this.a = a;
  }
}

const foo = new Foo(1);
const bar = new Bar(1);

// Default behavior - fails due to different constructors
const assert1 = new Assert();
assert1.deepStrictEqual(foo, bar); // AssertionError

// Skip prototype comparison - passes if properties are equal
const assert2 = new Assert({ skipPrototype: true });
assert2.deepStrictEqual(foo, bar); // OK copy

assert(value[, message])#

• value <any> 被檢查是否為真值的輸入。
• message <string> | <Error>

assert.ok() 的別名。

assert.deepEqual(actual, expected[, message])#

• actual <any>
• expected <any>
• message <string> | <Error>

嚴格斷言模式

assert.deepStrictEqual() 的別名。

舊式斷言模式

測試 actual 和 expected 引數之間的深度相等性。考慮改用 assert.deepStrictEqual()。 assert.deepEqual() 可能會產生令人意外的結果。

深度相等意味著子物件的可列舉“自有”屬性也按照以下規則進行遞迴評估。

import assert from 'node:assert';
// WARNING: This does not throw an AssertionError!

assert.deepEqual('+00000000', false);const assert = require('node:assert');
// WARNING: This does not throw an AssertionError!

assert.deepEqual('+00000000', false);copy

import assert from 'node:assert';

const obj1 = {
  a: {
    b: 1,
  },
};
const obj2 = {
  a: {
    b: 2,
  },
};
const obj3 = {
  a: {
    b: 1,
  },
};
const obj4 = { __proto__: obj1 };

assert.deepEqual(obj1, obj1);
// OK

// Values of b are different:
assert.deepEqual(obj1, obj2);
// AssertionError: { a: { b: 1 } } deepEqual { a: { b: 2 } }

assert.deepEqual(obj1, obj3);
// OK

// Prototypes are ignored:
assert.deepEqual(obj1, obj4);
// AssertionError: { a: { b: 1 } } deepEqual {}const assert = require('node:assert');

const obj1 = {
  a: {
    b: 1,
  },
};
const obj2 = {
  a: {
    b: 2,
  },
};
const obj3 = {
  a: {
    b: 1,
  },
};
const obj4 = { __proto__: obj1 };

assert.deepEqual(obj1, obj1);
// OK

// Values of b are different:
assert.deepEqual(obj1, obj2);
// AssertionError: { a: { b: 1 } } deepEqual { a: { b: 2 } }

assert.deepEqual(obj1, obj3);
// OK

// Prototypes are ignored:
assert.deepEqual(obj1, obj4);
// AssertionError: { a: { b: 1 } } deepEqual {}copy

assert.deepStrictEqual(actual, expected[, message])#

• actual <any>
• expected <any>
• message <string> | <Error>

測試 actual 和 expected 引數之間的深度嚴格相等性。“深度”相等意味著子物件的可列舉“自有”屬性也按照以下規則進行遞迴評估。

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
//
// + 2018-04-26T00:49:08.604Z
// - 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 obj = {};

weakMap1.set(obj, 'value');
weakMap2.set(obj, 'value');

// Comparing different instances fails, even with same contents
assert.deepStrictEqual(weakMap1, weakMap2);
// AssertionError: Values have same structure but are not reference-equal:
//
// WeakMap {
//   <items unknown>
// }

// Comparing the same instance to itself succeeds
assert.deepStrictEqual(weakMap1, weakMap1);
// OK

const weakSet1 = new WeakSet();
const weakSet2 = new WeakSet();
weakSet1.add(obj);
weakSet2.add(obj);

// Comparing different instances fails, even with same contents
assert.deepStrictEqual(weakSet1, weakSet2);
// AssertionError: Values have same structure but are not reference-equal:
// + actual - expected
//
// WeakSet {
//   <items unknown>
// }

// Comparing the same instance to itself succeeds
assert.deepStrictEqual(weakSet1, weakSet1);
// OKconst 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
//
// + 2018-04-26T00:49:08.604Z
// - 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 obj = {};

weakMap1.set(obj, 'value');
weakMap2.set(obj, 'value');

// Comparing different instances fails, even with same contents
assert.deepStrictEqual(weakMap1, weakMap2);
// AssertionError: Values have same structure but are not reference-equal:
//
// WeakMap {
//   <items unknown>
// }

// Comparing the same instance to itself succeeds
assert.deepStrictEqual(weakMap1, weakMap1);
// OK

const weakSet1 = new WeakSet();
const weakSet2 = new WeakSet();
weakSet1.add(obj);
weakSet2.add(obj);

// Comparing different instances fails, even with same contents
assert.deepStrictEqual(weakSet1, weakSet2);
// AssertionError: Values have same structure but are not reference-equal:
// + actual - expected
//
// WeakSet {
//   <items unknown>
// }

// Comparing the same instance to itself succeeds
assert.deepStrictEqual(weakSet1, weakSet1);
// OKcopy

assert.doesNotMatch(string, regexp[, message])#

• string <string>
• regexp <RegExp>
• message <string> | <Error>

期望 string 輸入與正則表示式不匹配。

import assert from 'node:assert/strict';

assert.doesNotMatch('I will fail', /fail/);
// AssertionError [ERR_ASSERTION]: The input was expected to not match the ...

assert.doesNotMatch(123, /pass/);
// AssertionError [ERR_ASSERTION]: The "string" argument must be of type string.

assert.doesNotMatch('I will pass', /different/);
// OKconst assert = require('node:assert/strict');

assert.doesNotMatch('I will fail', /fail/);
// AssertionError [ERR_ASSERTION]: The input was expected to not match the ...

assert.doesNotMatch(123, /pass/);
// AssertionError [ERR_ASSERTION]: The "string" argument must be of type string.

assert.doesNotMatch('I will pass', /different/);
// OKcopy

如果值確實匹配，或者 string 引數不是 string 型別，則會丟擲一個 AssertionError，其 message 屬性等於 message 引數的值。如果 message 引數未定義，則會分配一個預設的錯誤訊息。如果 message 引數是 <Error> 的例項，則會丟擲該 <Error> 例項而不是 AssertionError。

assert.doesNotReject(asyncFn[, error][, message])#

• asyncFn <Function> | <Promise>
• error <RegExp> | <Function>
• message <string>
• 返回：<Promise>

等待 asyncFn promise 完成，或者如果 asyncFn 是一個函式，則立即呼叫該函式並等待返回的 promise 完成。然後它將檢查該 promise 沒有被拒絕（rejected）。

如果 asyncFn 是一個函式並且它同步地丟擲一個錯誤，assert.doesNotReject() 將返回一個帶有該錯誤的被拒絕的 Promise。如果該函式不返回一個 promise，assert.doesNotReject() 將返回一個帶有 ERR_INVALID_RETURN_VALUE 錯誤的被拒絕的 Promise。在這兩種情況下，錯誤處理程式都會被跳過。

使用 assert.doesNotReject() 實際上沒什麼用，因為捕獲一個拒絕然後再次拒絕它的好處很小。相反，可以考慮在不應該拒絕的特定程式碼路徑旁邊添加註釋，並保持錯誤訊息儘可能具有表現力。

如果指定了 error，它可以是一個Class、<RegExp> 或一個驗證函式。更多詳情請參閱 assert.throws()。

除了等待完成的非同步特性外，其行為與 assert.doesNotThrow() 完全相同。

import assert from 'node:assert/strict';

await assert.doesNotReject(
  async () => {
    throw new TypeError('Wrong value');
  },
  SyntaxError,
);const assert = require('node:assert/strict');

(async () => {
  await assert.doesNotReject(
    async () => {
      throw new TypeError('Wrong value');
    },
    SyntaxError,
  );
})();copy

import assert from 'node:assert/strict';

assert.doesNotReject(Promise.reject(new TypeError('Wrong value')))
  .then(() => {
    // ...
  });const assert = require('node:assert/strict');

assert.doesNotReject(Promise.reject(new TypeError('Wrong value')))
  .then(() => {
    // ...
  });copy

assert.doesNotThrow(fn[, error][, message])#

• fn <Function>
• error <RegExp> | <Function>
• message <string>

斷言函式 fn 不會丟擲錯誤。

使用 assert.doesNotThrow() 實際上沒什麼用，因為捕獲一個錯誤然後重新丟擲它沒有任何好處。相反，可以考慮在不應該丟擲錯誤的特定程式碼路徑旁邊添加註釋，並保持錯誤訊息儘可能具有表現力。

當呼叫 assert.doesNotThrow() 時，它將立即呼叫 fn 函式。

如果丟擲了一個錯誤，並且該錯誤的型別與 error 引數指定的型別相同，則會丟擲一個 AssertionError。如果錯誤的型別不同，或者 error 引數未定義，則該錯誤會傳播回撥用者。

如果指定了 error，它可以是一個Class、<RegExp> 或一個驗證函式。更多詳情請參閱 assert.throws()。

例如，以下程式碼將丟擲 <TypeError>，因為斷言中沒有匹配的錯誤型別。

import assert from 'node:assert/strict';

assert.doesNotThrow(
  () => {
    throw new TypeError('Wrong value');
  },
  SyntaxError,
);const assert = require('node:assert/strict');

assert.doesNotThrow(
  () => {
    throw new TypeError('Wrong value');
  },
  SyntaxError,
);copy

但是，以下程式碼將導致一個 AssertionError，其訊息為“Got unwanted exception...”（收到了不期望的異常...）。

import assert from 'node:assert/strict';

assert.doesNotThrow(
  () => {
    throw new TypeError('Wrong value');
  },
  TypeError,
);const assert = require('node:assert/strict');

assert.doesNotThrow(
  () => {
    throw new TypeError('Wrong value');
  },
  TypeError,
);copy

如果丟擲了 AssertionError 並且為 message 引數提供了值，則 message 的值將被附加到 AssertionError 訊息中。

import assert from 'node:assert/strict';

assert.doesNotThrow(
  () => {
    throw new TypeError('Wrong value');
  },
  /Wrong value/,
  'Whoops',
);
// Throws: AssertionError: Got unwanted exception: Whoopsconst assert = require('node:assert/strict');

assert.doesNotThrow(
  () => {
    throw new TypeError('Wrong value');
  },
  /Wrong value/,
  'Whoops',
);
// Throws: AssertionError: Got unwanted exception: Whoopscopy

assert.equal(actual, expected[, message])#

• actual <any>
• expected <any>
• message <string> | <Error>

嚴格斷言模式

assert.strictEqual() 的別名。

舊式斷言模式

使用== 運算子測試 actual 和 expected 引數之間的淺層、強制型別轉換的相等性。NaN 會被特殊處理，如果兩側都是 NaN，則被視為相同。

import assert from 'node:assert';

assert.equal(1, 1);
// OK, 1 == 1
assert.equal(1, '1');
// OK, 1 == '1'
assert.equal(NaN, NaN);
// OK

assert.equal(1, 2);
// AssertionError: 1 == 2
assert.equal({ a: { b: 1 } }, { a: { b: 1 } });
// AssertionError: { a: { b: 1 } } == { a: { b: 1 } }const assert = require('node:assert');

assert.equal(1, 1);
// OK, 1 == 1
assert.equal(1, '1');
// OK, 1 == '1'
assert.equal(NaN, NaN);
// OK

assert.equal(1, 2);
// AssertionError: 1 == 2
assert.equal({ a: { b: 1 } }, { a: { b: 1 } });
// AssertionError: { a: { b: 1 } } == { a: { b: 1 } }copy

如果值不相等，則會丟擲一個 AssertionError，其 message 屬性等於 message 引數的值。如果 message 引數未定義，則會分配一個預設的錯誤訊息。如果 message 引數是 <Error> 的例項，則會丟擲該 <Error> 例項而不是 AssertionError。

assert.fail([message])#

• message <string> | <Error> 預設值: 'Failed'

丟擲一個帶有提供的錯誤訊息或預設錯誤訊息的 AssertionError。如果 message 引數是 <Error> 的例項，則會丟擲該 <Error> 例項而不是 AssertionError。

import assert from 'node:assert/strict';

assert.fail();
// AssertionError [ERR_ASSERTION]: Failed

assert.fail('boom');
// AssertionError [ERR_ASSERTION]: boom

assert.fail(new TypeError('need array'));
// TypeError: need arrayconst assert = require('node:assert/strict');

assert.fail();
// AssertionError [ERR_ASSERTION]: Failed

assert.fail('boom');
// AssertionError [ERR_ASSERTION]: boom

assert.fail(new TypeError('need array'));
// TypeError: need arraycopy

assert.ifError(value)#

• value <any>

如果 value 不是 undefined 或 null，則丟擲 value。這在測試回撥函式中的 error 引數時很有用。堆疊跟蹤包含從傳遞給 ifError() 的錯誤中的所有幀，包括可能為 ifError() 本身新增的幀。

import assert from 'node:assert/strict';

assert.ifError(null);
// OK
assert.ifError(0);
// AssertionError [ERR_ASSERTION]: ifError got unwanted exception: 0
assert.ifError('error');
// AssertionError [ERR_ASSERTION]: ifError got unwanted exception: 'error'
assert.ifError(new Error());
// AssertionError [ERR_ASSERTION]: ifError got unwanted exception: Error

// Create some random error frames.
let err;
(function errorFrame() {
  err = new Error('test error');
})();

(function ifErrorFrame() {
  assert.ifError(err);
})();
// AssertionError [ERR_ASSERTION]: ifError got unwanted exception: test error
//     at ifErrorFrame
//     at errorFrameconst assert = require('node:assert/strict');

assert.ifError(null);
// OK
assert.ifError(0);
// AssertionError [ERR_ASSERTION]: ifError got unwanted exception: 0
assert.ifError('error');
// AssertionError [ERR_ASSERTION]: ifError got unwanted exception: 'error'
assert.ifError(new Error());
// AssertionError [ERR_ASSERTION]: ifError got unwanted exception: Error

// Create some random error frames.
let err;
(function errorFrame() {
  err = new Error('test error');
})();

(function ifErrorFrame() {
  assert.ifError(err);
})();
// AssertionError [ERR_ASSERTION]: ifError got unwanted exception: test error
//     at ifErrorFrame
//     at errorFramecopy

assert.match(string, regexp[, message])#

• string <string>
• regexp <RegExp>
• message <string> | <Error>

期望 string 輸入與正則表示式匹配。

import assert from 'node:assert/strict';

assert.match('I will fail', /pass/);
// AssertionError [ERR_ASSERTION]: The input did not match the regular ...

assert.match(123, /pass/);
// AssertionError [ERR_ASSERTION]: The "string" argument must be of type string.

assert.match('I will pass', /pass/);
// OKconst assert = require('node:assert/strict');

assert.match('I will fail', /pass/);
// AssertionError [ERR_ASSERTION]: The input did not match the regular ...

assert.match(123, /pass/);
// AssertionError [ERR_ASSERTION]: The "string" argument must be of type string.

assert.match('I will pass', /pass/);
// OKcopy

如果值不匹配，或者 string 引數不是 string 型別，則會丟擲一個 AssertionError，其 message 屬性等於 message 引數的值。如果 message 引數未定義，則會分配一個預設的錯誤訊息。如果 message 引數是 <Error> 的例項，則會丟擲該 <Error> 例項而不是 AssertionError。

assert.notDeepEqual(actual, expected[, message])#

• actual <any>
• expected <any>
• message <string> | <Error>

嚴格斷言模式

assert.notDeepStrictEqual() 的別名。

舊式斷言模式

測試任何深度不相等性。與 assert.deepEqual() 相反。

import assert from 'node:assert';

const obj1 = {
  a: {
    b: 1,
  },
};
const obj2 = {
  a: {
    b: 2,
  },
};
const obj3 = {
  a: {
    b: 1,
  },
};
const obj4 = { __proto__: obj1 };

assert.notDeepEqual(obj1, obj1);
// AssertionError: { a: { b: 1 } } notDeepEqual { a: { b: 1 } }

assert.notDeepEqual(obj1, obj2);
// OK

assert.notDeepEqual(obj1, obj3);
// AssertionError: { a: { b: 1 } } notDeepEqual { a: { b: 1 } }

assert.notDeepEqual(obj1, obj4);
// OKconst assert = require('node:assert');

const obj1 = {
  a: {
    b: 1,
  },
};
const obj2 = {
  a: {
    b: 2,
  },
};
const obj3 = {
  a: {
    b: 1,
  },
};
const obj4 = { __proto__: obj1 };

assert.notDeepEqual(obj1, obj1);
// AssertionError: { a: { b: 1 } } notDeepEqual { a: { b: 1 } }

assert.notDeepEqual(obj1, obj2);
// OK

assert.notDeepEqual(obj1, obj3);
// AssertionError: { a: { b: 1 } } notDeepEqual { a: { b: 1 } }

assert.notDeepEqual(obj1, obj4);
// OKcopy

如果值是深度相等的，則會丟擲一個 AssertionError，其 message 屬性等於 message 引數的值。如果 message 引數未定義，則會分配一個預設的錯誤訊息。如果 message 引數是 <Error> 的例項，則會丟擲該 <Error> 例項而不是 AssertionError。

assert.notDeepStrictEqual(actual, expected[, message])#

• actual <any>
• expected <any>
• message <string> | <Error>

測試深度嚴格不相等性。與 assert.deepStrictEqual() 相反。

import assert from 'node:assert/strict';

assert.notDeepStrictEqual({ a: 1 }, { a: '1' });
// OKconst assert = require('node:assert/strict');

assert.notDeepStrictEqual({ a: 1 }, { a: '1' });
// OKcopy

如果值是深度且嚴格相等的，則會丟擲一個 AssertionError，其 message 屬性等於 message 引數的值。如果 message 引數未定義，則會分配一個預設的錯誤訊息。如果 message 引數是 <Error> 的例項，則會丟擲該 <Error> 例項而不是 AssertionError。

assert.notEqual(actual, expected[, message])#

• actual <any>
• expected <any>
• message <string> | <Error>

嚴格斷言模式

assert.notStrictEqual() 的別名。

舊式斷言模式

使用!= 運算子測試淺層、強制型別轉換的不相等性。NaN 會被特殊處理，如果兩側都是 NaN，則被視為相同。

import assert from 'node:assert';

assert.notEqual(1, 2);
// OK

assert.notEqual(1, 1);
// AssertionError: 1 != 1

assert.notEqual(1, '1');
// AssertionError: 1 != '1'const assert = require('node:assert');

assert.notEqual(1, 2);
// OK

assert.notEqual(1, 1);
// AssertionError: 1 != 1

assert.notEqual(1, '1');
// AssertionError: 1 != '1'copy

如果值相等，則會丟擲一個 AssertionError，其 message 屬性等於 message 引數的值。如果 message 引數未定義，則會分配一個預設的錯誤訊息。如果 message 引數是 <Error> 的例項，則會丟擲該 <Error> 例項而不是 AssertionError。

assert.notStrictEqual(actual, expected[, message])#

• actual <any>
• expected <any>
• message <string> | <Error>

測試由 Object.is() 決定的 actual 和 expected 引數之間的嚴格不相等性。

import assert from 'node:assert/strict';

assert.notStrictEqual(1, 2);
// OK

assert.notStrictEqual(1, 1);
// AssertionError [ERR_ASSERTION]: Expected "actual" to be strictly unequal to:
//
// 1

assert.notStrictEqual(1, '1');
// OKconst assert = require('node:assert/strict');

assert.notStrictEqual(1, 2);
// OK

assert.notStrictEqual(1, 1);
// AssertionError [ERR_ASSERTION]: Expected "actual" to be strictly unequal to:
//
// 1

assert.notStrictEqual(1, '1');
// OKcopy

如果值是嚴格相等的，則會丟擲一個 AssertionError，其 message 屬性等於 message 引數的值。如果 message 引數未定義，則會分配一個預設的錯誤訊息。如果 message 引數是 <Error> 的例項，則會丟擲該 <Error> 例項而不是 AssertionError。

assert.ok(value[, message])#

• value <any>
• message <string> | <Error>

測試 value 是否為真值（truthy）。它等同於 assert.equal(!!value, true, message)。

如果 value 不是真值，則會丟擲一個 AssertionError，其 message 屬性等於 message 引數的值。如果 message 引數是 undefined，則會分配一個預設的錯誤訊息。如果 message 引數是 <Error> 的例項，則會丟擲該 <Error> 例項而不是 AssertionError。如果根本沒有傳入任何引數，message 將被設定為字串：'No value argument passed to `assert.ok()`'（沒有值引數傳遞給 `assert.ok()`）。

請注意，在 repl 中，錯誤訊息將與在檔案中丟擲的錯誤訊息不同！詳情見下文。

import assert from 'node:assert/strict';

assert.ok(true);
// OK
assert.ok(1);
// OK

assert.ok();
// AssertionError: No value argument passed to `assert.ok()`

assert.ok(false, 'it\'s false');
// AssertionError: it's false

// In the repl:
assert.ok(typeof 123 === 'string');
// AssertionError: false == true

// In a file (e.g. test.js):
assert.ok(typeof 123 === 'string');
// AssertionError: The expression evaluated to a falsy value:
//
//   assert.ok(typeof 123 === 'string')

assert.ok(false);
// AssertionError: The expression evaluated to a falsy value:
//
//   assert.ok(false)

assert.ok(0);
// AssertionError: The expression evaluated to a falsy value:
//
//   assert.ok(0)const assert = require('node:assert/strict');

assert.ok(true);
// OK
assert.ok(1);
// OK

assert.ok();
// AssertionError: No value argument passed to `assert.ok()`

assert.ok(false, 'it\'s false');
// AssertionError: it's false

// In the repl:
assert.ok(typeof 123 === 'string');
// AssertionError: false == true

// In a file (e.g. test.js):
assert.ok(typeof 123 === 'string');
// AssertionError: The expression evaluated to a falsy value:
//
//   assert.ok(typeof 123 === 'string')

assert.ok(false);
// AssertionError: The expression evaluated to a falsy value:
//
//   assert.ok(false)

assert.ok(0);
// AssertionError: The expression evaluated to a falsy value:
//
//   assert.ok(0)copy

import assert from 'node:assert/strict';

// Using `assert()` works the same:
assert(0);
// AssertionError: The expression evaluated to a falsy value:
//
//   assert(0)const assert = require('node:assert');

// Using `assert()` works the same:
assert(0);
// AssertionError: The expression evaluated to a falsy value:
//
//   assert(0)copy

assert.rejects(asyncFn[, error][, message])#

• asyncFn <Function> | <Promise>
• error <RegExp> | <Function> | <Object> | <Error>
• message <string>
• 返回：<Promise>

等待 asyncFn promise 完成，或者如果 asyncFn 是一個函式，則立即呼叫該函式並等待返回的 promise 完成。然後它將檢查該 promise 被拒絕（rejected）。

如果 asyncFn 是一個函式並且它同步地丟擲一個錯誤，assert.rejects() 將返回一個帶有該錯誤的被拒絕的 Promise。如果該函式不返回一個 promise，assert.rejects() 將返回一個帶有 ERR_INVALID_RETURN_VALUE 錯誤的被拒絕的 Promise。在這兩種情況下，錯誤處理程式都會被跳過。

除了等待完成的非同步特性外，其行為與 assert.throws() 完全相同。

如果指定了 error，它可以是一個Class、<RegExp>、一個驗證函式、一個每個屬性都會被測試的物件，或者一個每個屬性（包括不可列舉的 message 和 name 屬性）都會被測試的錯誤例項。

如果指定了 message，它將作為 asyncFn 未能拒絕時 AssertionError 提供的訊息。

import assert from 'node:assert/strict';

await assert.rejects(
  async () => {
    throw new TypeError('Wrong value');
  },
  {
    name: 'TypeError',
    message: 'Wrong value',
  },
);const assert = require('node:assert/strict');

(async () => {
  await assert.rejects(
    async () => {
      throw new TypeError('Wrong value');
    },
    {
      name: 'TypeError',
      message: 'Wrong value',
    },
  );
})();copy

import assert from 'node:assert/strict';

await assert.rejects(
  async () => {
    throw new TypeError('Wrong value');
  },
  (err) => {
    assert.strictEqual(err.name, 'TypeError');
    assert.strictEqual(err.message, 'Wrong value');
    return true;
  },
);const assert = require('node:assert/strict');

(async () => {
  await assert.rejects(
    async () => {
      throw new TypeError('Wrong value');
    },
    (err) => {
      assert.strictEqual(err.name, 'TypeError');
      assert.strictEqual(err.message, 'Wrong value');
      return true;
    },
  );
})();copy

import assert from 'node:assert/strict';

assert.rejects(
  Promise.reject(new Error('Wrong value')),
  Error,
).then(() => {
  // ...
});const assert = require('node:assert/strict');

assert.rejects(
  Promise.reject(new Error('Wrong value')),
  Error,
).then(() => {
  // ...
});copy

error 不能是字串。如果一個字串作為第二個引數提供，那麼 error 將被假定為省略，而該字串將用於 message。這可能導致容易忽略的錯誤。如果考慮使用字串作為第二個引數，請仔細閱讀 assert.throws() 中的示例。

assert.strictEqual(actual, expected[, message])#

• actual <any>
• expected <any>
• message <string> | <Error>

測試由 Object.is() 決定的 actual 和 expected 引數之間的嚴格相等性。

import assert from 'node:assert/strict';

assert.strictEqual(1, 2);
// AssertionError [ERR_ASSERTION]: Expected inputs to be strictly equal:
//
// 1 !== 2

assert.strictEqual(1, 1);
// OK

assert.strictEqual('Hello foobar', 'Hello World!');
// AssertionError [ERR_ASSERTION]: Expected inputs to be strictly equal:
// + actual - expected
//
// + 'Hello foobar'
// - 'Hello World!'
//          ^

const apples = 1;
const oranges = 2;
assert.strictEqual(apples, oranges, `apples ${apples} !== oranges ${oranges}`);
// AssertionError [ERR_ASSERTION]: apples 1 !== oranges 2

assert.strictEqual(1, '1', new TypeError('Inputs are not identical'));
// TypeError: Inputs are not identicalconst assert = require('node:assert/strict');

assert.strictEqual(1, 2);
// AssertionError [ERR_ASSERTION]: Expected inputs to be strictly equal:
//
// 1 !== 2

assert.strictEqual(1, 1);
// OK

assert.strictEqual('Hello foobar', 'Hello World!');
// AssertionError [ERR_ASSERTION]: Expected inputs to be strictly equal:
// + actual - expected
//
// + 'Hello foobar'
// - 'Hello World!'
//          ^

const apples = 1;
const oranges = 2;
assert.strictEqual(apples, oranges, `apples ${apples} !== oranges ${oranges}`);
// AssertionError [ERR_ASSERTION]: apples 1 !== oranges 2

assert.strictEqual(1, '1', new TypeError('Inputs are not identical'));
// TypeError: Inputs are not identicalcopy

如果值不是嚴格相等的，則會丟擲一個 AssertionError，其 message 屬性等於 message 引數的值。如果 message 引數未定義，則會分配一個預設的錯誤訊息。如果 message 引數是 <Error> 的例項，則會丟擲該 <Error> 例項而不是 AssertionError。

assert.throws(fn[, error][, message])#

• fn <Function>
• error <RegExp> | <Function> | <Object> | <Error>
• message <string>

期望函式 fn 丟擲一個錯誤。

如果指定了 error，它可以是一個Class、<RegExp>、一個驗證函式、一個每個屬性都會進行嚴格深度相等測試的驗證物件，或者一個每個屬性（包括不可列舉的 message 和 name 屬性）都會進行嚴格深度相等測試的錯誤例項。當使用物件時，也可以使用正則表示式來驗證字串屬性。示例見下文。

如果指定了 message，它將被附加到 fn 呼叫未能丟擲錯誤或錯誤驗證失敗時由 AssertionError 提供的訊息中。

自定義驗證物件/錯誤例項

import assert from 'node:assert/strict';

const err = new TypeError('Wrong value');
err.code = 404;
err.foo = 'bar';
err.info = {
  nested: true,
  baz: 'text',
};
err.reg = /abc/i;

assert.throws(
  () => {
    throw err;
  },
  {
    name: 'TypeError',
    message: 'Wrong value',
    info: {
      nested: true,
      baz: 'text',
    },
    // Only properties on the validation object will be tested for.
    // Using nested objects requires all properties to be present. Otherwise
    // the validation is going to fail.
  },
);

// Using regular expressions to validate error properties:
assert.throws(
  () => {
    throw err;
  },
  {
    // The `name` and `message` properties are strings and using regular
    // expressions on those will match against the string. If they fail, an
    // error is thrown.
    name: /^TypeError$/,
    message: /Wrong/,
    foo: 'bar',
    info: {
      nested: true,
      // It is not possible to use regular expressions for nested properties!
      baz: 'text',
    },
    // The `reg` property contains a regular expression and only if the
    // validation object contains an identical regular expression, it is going
    // to pass.
    reg: /abc/i,
  },
);

// Fails due to the different `message` and `name` properties:
assert.throws(
  () => {
    const otherErr = new Error('Not found');
    // Copy all enumerable properties from `err` to `otherErr`.
    for (const [key, value] of Object.entries(err)) {
      otherErr[key] = value;
    }
    throw otherErr;
  },
  // The error's `message` and `name` properties will also be checked when using
  // an error as validation object.
  err,
);const assert = require('node:assert/strict');

const err = new TypeError('Wrong value');
err.code = 404;
err.foo = 'bar';
err.info = {
  nested: true,
  baz: 'text',
};
err.reg = /abc/i;

assert.throws(
  () => {
    throw err;
  },
  {
    name: 'TypeError',
    message: 'Wrong value',
    info: {
      nested: true,
      baz: 'text',
    },
    // Only properties on the validation object will be tested for.
    // Using nested objects requires all properties to be present. Otherwise
    // the validation is going to fail.
  },
);

// Using regular expressions to validate error properties:
assert.throws(
  () => {
    throw err;
  },
  {
    // The `name` and `message` properties are strings and using regular
    // expressions on those will match against the string. If they fail, an
    // error is thrown.
    name: /^TypeError$/,
    message: /Wrong/,
    foo: 'bar',
    info: {
      nested: true,
      // It is not possible to use regular expressions for nested properties!
      baz: 'text',
    },
    // The `reg` property contains a regular expression and only if the
    // validation object contains an identical regular expression, it is going
    // to pass.
    reg: /abc/i,
  },
);

// Fails due to the different `message` and `name` properties:
assert.throws(
  () => {
    const otherErr = new Error('Not found');
    // Copy all enumerable properties from `err` to `otherErr`.
    for (const [key, value] of Object.entries(err)) {
      otherErr[key] = value;
    }
    throw otherErr;
  },
  // The error's `message` and `name` properties will also be checked when using
  // an error as validation object.
  err,
);copy

使用建構函式驗證 instanceof

import assert from 'node:assert/strict';

assert.throws(
  () => {
    throw new Error('Wrong value');
  },
  Error,
);const assert = require('node:assert/strict');

assert.throws(
  () => {
    throw new Error('Wrong value');
  },
  Error,
);copy

使用 <RegExp> 驗證錯誤訊息

使用正則表示式會對錯誤物件執行 .toString，因此也會包含錯誤名稱。

import assert from 'node:assert/strict';

assert.throws(
  () => {
    throw new Error('Wrong value');
  },
  /^Error: Wrong value$/,
);const assert = require('node:assert/strict');

assert.throws(
  () => {
    throw new Error('Wrong value');
  },
  /^Error: Wrong value$/,
);copy

自定義錯誤驗證

該函式必須返回 true 以表示所有內部驗證都通過了。否則，它將因 AssertionError 而失敗。

import assert from 'node:assert/strict';

assert.throws(
  () => {
    throw new Error('Wrong value');
  },
  (err) => {
    assert(err instanceof Error);
    assert(/value/.test(err));
    // Avoid returning anything from validation functions besides `true`.
    // Otherwise, it's not clear what part of the validation failed. Instead,
    // throw an error about the specific validation that failed (as done in this
    // example) and add as much helpful debugging information to that error as
    // possible.
    return true;
  },
  'unexpected error',
);const assert = require('node:assert/strict');

assert.throws(
  () => {
    throw new Error('Wrong value');
  },
  (err) => {
    assert(err instanceof Error);
    assert(/value/.test(err));
    // Avoid returning anything from validation functions besides `true`.
    // Otherwise, it's not clear what part of the validation failed. Instead,
    // throw an error about the specific validation that failed (as done in this
    // example) and add as much helpful debugging information to that error as
    // possible.
    return true;
  },
  'unexpected error',
);copy

error 不能是字串。如果一個字串作為第二個引數提供，那麼 error 將被假定為省略，而該字串將用於 message。這可能導致容易忽略的錯誤。使用與丟擲的錯誤訊息相同的訊息將導致一個 ERR_AMBIGUOUS_ARGUMENT 錯誤。如果考慮使用字串作為第二個引數，請仔細閱讀下面的示例。

import assert from 'node:assert/strict';

function throwingFirst() {
  throw new Error('First');
}

function throwingSecond() {
  throw new Error('Second');
}

function notThrowing() {}

// The second argument is a string and the input function threw an Error.
// The first case will not throw as it does not match for the error message
// thrown by the input function!
assert.throws(throwingFirst, 'Second');
// In the next example the message has no benefit over the message from the
// error and since it is not clear if the user intended to actually match
// against the error message, Node.js throws an `ERR_AMBIGUOUS_ARGUMENT` error.
assert.throws(throwingSecond, 'Second');
// TypeError [ERR_AMBIGUOUS_ARGUMENT]

// The string is only used (as message) in case the function does not throw:
assert.throws(notThrowing, 'Second');
// AssertionError [ERR_ASSERTION]: Missing expected exception: Second

// If it was intended to match for the error message do this instead:
// It does not throw because the error messages match.
assert.throws(throwingSecond, /Second$/);

// If the error message does not match, an AssertionError is thrown.
assert.throws(throwingFirst, /Second$/);
// AssertionError [ERR_ASSERTION]const assert = require('node:assert/strict');

function throwingFirst() {
  throw new Error('First');
}

function throwingSecond() {
  throw new Error('Second');
}

function notThrowing() {}

// The second argument is a string and the input function threw an Error.
// The first case will not throw as it does not match for the error message
// thrown by the input function!
assert.throws(throwingFirst, 'Second');
// In the next example the message has no benefit over the message from the
// error and since it is not clear if the user intended to actually match
// against the error message, Node.js throws an `ERR_AMBIGUOUS_ARGUMENT` error.
assert.throws(throwingSecond, 'Second');
// TypeError [ERR_AMBIGUOUS_ARGUMENT]

// The string is only used (as message) in case the function does not throw:
assert.throws(notThrowing, 'Second');
// AssertionError [ERR_ASSERTION]: Missing expected exception: Second

// If it was intended to match for the error message do this instead:
// It does not throw because the error messages match.
assert.throws(throwingSecond, /Second$/);

// If the error message does not match, an AssertionError is thrown.
assert.throws(throwingFirst, /Second$/);
// AssertionError [ERR_ASSERTION]copy

由於這種表示法容易出錯且令人困惑，請避免使用字串作為第二個引數。

assert.partialDeepStrictEqual(actual, expected[, message])#

• actual <any>
• expected <any>
• message <string> | <Error>

測試 actual 和 expected 引數之間的部分深度相等性。“深度”相等意味著子物件的可列舉“自有”屬性也按照以下規則進行遞迴評估。“部分”相等意味著只比較存在於 expected 引數上的屬性。

該方法總是能透過與 assert.deepStrictEqual() 相同的測試用例，其行為是後者的一個超集。

import assert from 'node:assert';

assert.partialDeepStrictEqual(
  { a: { b: { c: 1 } } },
  { a: { b: { c: 1 } } },
);
// OK

assert.partialDeepStrictEqual(
  { a: 1, b: 2, c: 3 },
  { b: 2 },
);
// OK

assert.partialDeepStrictEqual(
  [1, 2, 3, 4, 5, 6, 7, 8, 9],
  [4, 5, 8],
);
// OK

assert.partialDeepStrictEqual(
  new Set([{ a: 1 }, { b: 1 }]),
  new Set([{ a: 1 }]),
);
// OK

assert.partialDeepStrictEqual(
  new Map([['key1', 'value1'], ['key2', 'value2']]),
  new Map([['key2', 'value2']]),
);
// OK

assert.partialDeepStrictEqual(123n, 123n);
// OK

assert.partialDeepStrictEqual(
  [1, 2, 3, 4, 5, 6, 7, 8, 9],
  [5, 4, 8],
);
// AssertionError

assert.partialDeepStrictEqual(
  { a: 1 },
  { a: 1, b: 2 },
);
// AssertionError

assert.partialDeepStrictEqual(
  { a: { b: 2 } },
  { a: { b: '2' } },
);
// AssertionErrorconst assert = require('node:assert');

assert.partialDeepStrictEqual(
  { a: { b: { c: 1 } } },
  { a: { b: { c: 1 } } },
);
// OK

assert.partialDeepStrictEqual(
  { a: 1, b: 2, c: 3 },
  { b: 2 },
);
// OK

assert.partialDeepStrictEqual(
  [1, 2, 3, 4, 5, 6, 7, 8, 9],
  [4, 5, 8],
);
// OK

assert.partialDeepStrictEqual(
  new Set([{ a: 1 }, { b: 1 }]),
  new Set([{ a: 1 }]),
);
// OK

assert.partialDeepStrictEqual(
  new Map([['key1', 'value1'], ['key2', 'value2']]),
  new Map([['key2', 'value2']]),
);
// OK

assert.partialDeepStrictEqual(123n, 123n);
// OK

assert.partialDeepStrictEqual(
  [1, 2, 3, 4, 5, 6, 7, 8, 9],
  [5, 4, 8],
);
// AssertionError

assert.partialDeepStrictEqual(
  { a: 1 },
  { a: 1, b: 2 },
);
// AssertionError

assert.partialDeepStrictEqual(
  { a: { b: 2 } },
  { a: { b: '2' } },
);
// AssertionErrorcopy