assert.ok(value[, message])


测试 value 是否为真值。 等同于 assert.equal(!!value, true, message)

如果 value 不是真值,则抛出 AssertionError,并将 message 属性设置为等于 message 参数的值。 如果未定义 message 参数,则会分配默认错误消息。 如果 message 参数是 Error 的实例,则它将被抛出而不是 AssertionError。 如果没有传入任何参数,则将 message 设置为字符串:'No value argument passed to `assert.ok()`'

注意,在 repl 中,错误消息将与文件中抛出的错误消息不同!请参阅下文了解更多详情。

const assert = require('assert').strict;

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

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

assert.ok(false, '这是假值');
// AssertionError: 这是假值

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

// 在文件中(例如 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)

// 与使用 `assert()` 相同:
assert(0);
// AssertionError: The expression evaluated to a falsy value:
//
//   assert(0)

Tests if value is truthy. It is equivalent to assert.equal(!!value, true, message).

If value is not truthy, 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. If no arguments are passed in at all message will be set to the string: 'No value argument passed to `assert.ok()`'.

Be aware that in the repl the error message will be different to the one thrown in a file! See below for further details.

const assert = require('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)

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