prefer-promise-reject-errors
需要使用 Error 对象作为 Promise 拒绝的原因
对于 Promises 中的用户定义错误，仅将内置 Error 对象的实例传递给 reject() 函数被认为是一种很好的做法。Error 对象自动存储堆栈跟踪，可用于通过确定错误来自何处来调试错误。如果 Promise 以非 Error 值被拒绝，则可能很难确定拒绝发生的位置。
¥It is considered good practice to only pass instances of the built-in Error object to the reject() function for user-defined errors in Promises. Error objects automatically store a stack trace, which can be used to debug an error by determining where it came from. If a Promise is rejected with a non-Error value, it can be difficult to determine where the rejection occurred.
规则详情
¥Rule Details
该规则旨在确保 Promises 仅被 Error 对象拒绝。
¥This rule aims to ensure that Promises are only rejected with Error objects.
选项
¥Options
此规则采用一个可选对象参数：
¥This rule takes one optional object argument:
-
allowEmptyReject: true（默认为false）允许不带参数调用Promise.reject()。¥
allowEmptyReject: true(falseby default) allows calls toPromise.reject()with no arguments.
此规则的错误代码示例：
¥Examples of incorrect code for this rule:
/*eslint prefer-promise-reject-errors: "error"*/
Promise.reject("something bad happened");
Promise.reject(5);
Promise.reject();
new Promise(function(resolve, reject) {
reject("something bad happened");
});
new Promise(function(resolve, reject) {
reject();
});
此规则的正确代码示例：
¥Examples of correct code for this rule:
/*eslint prefer-promise-reject-errors: "error"*/
Promise.reject(new Error("something bad happened"));
Promise.reject(new TypeError("something bad happened"));
new Promise(function(resolve, reject) {
reject(new Error("something bad happened"));
});
var foo = getUnknownValue();
Promise.reject(foo);
使用 allowEmptyReject: true 选项的此规则的正确代码示例：
¥Examples of correct code for this rule with the allowEmptyReject: true option:
/*eslint prefer-promise-reject-errors: ["error", {"allowEmptyReject": true}]*/
Promise.reject();
new Promise(function(resolve, reject) {
reject();
});
已知限制
¥Known Limitations
由于静态分析的限制，这条规则不能保证你只会拒绝带有 Error 个对象的 Promises。虽然该规则将报告可以保证拒绝原因显然不是 Error 的情况，但不会报告给定原因是否为 Error 不确定的情况。有关此警告的更多信息，请参阅 no-throw-literal 规则中的 类似的限制。
¥Due to the limits of static analysis, this rule cannot guarantee that you will only reject Promises with Error objects. While the rule will report cases where it can guarantee that the rejection reason is clearly not an Error, it will not report cases where there is uncertainty about whether a given reason is an Error. For more information on this caveat, see the similar limitations in the no-throw-literal rule.
为了避免规则之间的冲突，此规则不会报告异步函数中 throw 语句中使用的非错误值，即使这些会导致 Promise 被拒绝。要针对这些情况进行检查，请使用 no-throw-literal 规则。
¥To avoid conflicts between rules, this rule does not report non-error values used in throw statements in async functions, even though these lead to Promise rejections. To lint for these cases, use the no-throw-literal rule.
何时不使用
¥When Not To Use It
如果你使用自定义非错误值作为 Promise 拒绝原因，你可以关闭此规则。
¥If you’re using custom non-error values as Promise rejection reasons, you can turn off this rule.
相关规则
版本
此规则是在 ESLint v3.14.0 中引入。