prefer-promise-reject-errors
要求使用 Error 对象作为 Promise 拒绝原因(prefer-promise-reject-errors)
只将内置Error
对象的实例传递给reject()
为了Promises中的用户定义错误的函数是一种很好的做法。Error
对象会自动存储堆栈跟踪,通过确定它来自何处,可用于调试错误。如果承诺以非Error
价值被拒绝,可能难以确定拒绝发生的地点。
规则细节
这条规则旨在确保承诺只被Error
对象拒绝。
选项
该规则采用一个可选的对象参数:
allowEmptyReject: true
(false
by default) allows calls toPromise.reject()
with no arguments.Examples ofincorrect
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( }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(fooExamples of correct code for this
rulewith t
heallowEmptyReject: true
option:/*eslint prefer-pr
omise-reject-errors: ["error", {"allowEmptyReject": true}]*/ Promise.reject( new Promise(function(resolve, reject) { reject( }Known LimitationsDue to the limits of static analysis, this rule cannot guarantee that you will only reject Promises with Error objects. While the rule will re
port caseswhere
it can guarantee that the rejection reason is clearly not an Error, it will not report caseswhere
there is uncertainty about whether a given reason is an Error. For more information on this c
aveat, see the similar limitations in the no-throw-literal rule.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.When Not To Use ItIf you’r
e using custom non-error values as Promise rejection reasons,
you can turn off this rule.Further Reading
no-throw-literal
版本
该规则在 ESLint 3.14.0中引入。