javascript - 为什么 Mozilla 认为条件捕获 block 是非标准的？

Question

我在这里阅读 Mozilla一个文档说 try...catch 条件是

"non-standard and is not on a standards track. Do not use it on production"

但我不明白为什么。

而且我想知道在可以为每种情况创建多个 response.status 的情况下，我如何才能做出此声明。例如，这是我现在的代码

    class BookController {
  async store ({ request, response }) {
    try {
      const values = { ...request.all(), user_id: request.user_id }

      const validatedValues = await importValidate.validate(values, rules, messages)
      return Book.create(validatedValues)
    } catch (e) {
      response.status(409).json(e)
    }
  }

而且我需要它是每种情况的倍数 response.status，对于基于我的规则的每个响应。

我目前正在使用 JS、Node、Adonis，在此验证过程中，Indicative/验证器

Answer 1

正如您阅读的文档所解释的那样:

Non-standard This feature is non-standard and is not on a standards track. Do not use it on production sites facing the Web: it will not work for every user. There may also be large incompatibilities between implementations and the behavior may change in the future.

在这种情况下，您最好定义自己的条件语句

代替

try {
    myroutine(); // may throw three types of exceptions
} catch (e if e instanceof TypeError) {
    // statements to handle TypeError exceptions
} catch (e if e instanceof RangeError) {
    // statements to handle RangeError exceptions
} catch (e if e instanceof EvalError) {
    // statements to handle EvalError exceptions
} catch (e) {
    // statements to handle any unspecified exceptions
    logMyErrors(e); // pass exception object to error handler
}

使用

try {
    myroutine(); // may throw three types of exceptions
} catch (e) {
    if (e instanceof TypeError) {
        // statements to handle TypeError exceptions
    } else if (e instanceof RangeError) {
        // statements to handle RangeError exceptions
    } else if (e instanceof EvalError) {
        // statements to handle EvalError exceptions
    } else {
        // statements to handle any unspecified exceptions
        logMyErrors(e); // pass exception object to error handler
    }
}

通过这种方式，您仍将单独处理所有异常，但在单个 catch 语句中