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


断言 fn 函数不会抛出错误。

使用 assert.doesNotThrow() 实际上没有用处,因为捕获错误然后重新抛出它没有任何好处。 应该考虑在不应抛出错误的特定代码路径旁边添加注释,并尽可能保留错误消息。

当调用 assert.doesNotThrow() 时,它将立即调用 fn 函数。

如果抛出错误并且它与 error 参数指定的类型相同,则抛出 AssertionError。 如果错误的类型不同,或者 error 参数未定义,则错误将传播回调用方。

如果指定,则 error 可以是 ClassRegExp 或验证函数。 有关更多详细信息,请参见 assert.throws()

例如,以下示例将抛出 TypeError,因为断言中没有匹配的错误类型:

assert.doesNotThrow(
  () => {
    throw new TypeError('错误值');
  },
  SyntaxError
);

以下示例将导致 AssertionError,并显示消息 'Got unwanted exception...':

assert.doesNotThrow(
  () => {
    throw new TypeError('错误值');
  },
  TypeError
);

如果抛出 AssertionError 并为 message 参数提供了值,则 message 的值将附加到 AssertionError 消息:

assert.doesNotThrow(
  () => {
    throw new TypeError('错误值');
  },
  /错误值/,
  '出错啦'
);
// AssertionError: Got unwanted exception: 出错啦

Asserts that the function fn does not throw an error.

Using assert.doesNotThrow() is actually not useful because there is no benefit in catching an error and then rethrowing it. Instead, consider adding a comment next to the specific code path that should not throw and keep error messages as expressive as possible.

When assert.doesNotThrow() is called, it will immediately call the fn function.

If an error is thrown and it is the same type as that specified by the error parameter, then an AssertionError is thrown. If the error is of a different type, or if the error parameter is undefined, the error is propagated back to the caller.

If specified, error can be a Class, RegExp or a validation function. See assert.throws() for more details.

The following, for instance, will throw the TypeError because there is no matching error type in the assertion:

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

However, the following will result in an AssertionError with the message 'Got unwanted exception...':

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

If an AssertionError is thrown and a value is provided for the message parameter, the value of message will be appended to the AssertionError message:

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