no-promise-executor-return
禁止从 Promise 执行器函数返回值
此规则报告的一些问题可通过编辑器建议手动修复
new Promise 构造函数接受一个参数，称为执行器。
¥The new Promise constructor accepts a single argument, called an executor.
const myPromise = new Promise(function executor(resolve, reject) {
readFile('foo.txt', function(err, result) {
if (err) {
reject(err);
} else {
resolve(result);
}
});
});
执行器函数通常会启动一些异步操作。完成后，执行程序应调用 resolve 并返回结果，如果发生错误则调用 reject。
¥The executor function usually initiates some asynchronous operation. Once it is finished, the executor should call resolve with the result, or reject if an error occurred.
执行器的返回值被忽略。从 executor 函数返回一个值是一个可能的错误，因为返回的值不能被使用并且它不会以任何方式影响 Promise。
¥The return value of the executor is ignored. Returning a value from an executor function is a possible error because the returned value cannot be used and it doesn’t affect the promise in any way.
规则详情
¥Rule Details
此规则不允许从 Promise 执行程序函数返回值。
¥This rule disallows returning values from Promise executor functions.
只允许没有值的 return，因为它是一个控制流语句。
¥Only return without a value is allowed, as it’s a control flow statement.
此规则的错误代码示例：
¥Examples of incorrect code for this rule:
/*eslint no-promise-executor-return: "error"*/
new Promise((resolve, reject) => {
if (someCondition) {
return defaultResult;
}
getSomething((err, result) => {
if (err) {
reject(err);
} else {
resolve(result);
}
});
});
new Promise((resolve, reject) => getSomething((err, data) => {
if (err) {
reject(err);
} else {
resolve(data);
}
}));
new Promise(() => {
return 1;
});
new Promise(r => r(1));
此规则的正确代码示例：
¥Examples of correct code for this rule:
/*eslint no-promise-executor-return: "error"*/
// Turn return inline into two lines
new Promise((resolve, reject) => {
if (someCondition) {
resolve(defaultResult);
return;
}
getSomething((err, result) => {
if (err) {
reject(err);
} else {
resolve(result);
}
});
});
// Add curly braces
new Promise((resolve, reject) => {
getSomething((err, data) => {
if (err) {
reject(err);
} else {
resolve(data);
}
});
});
new Promise(r => { r(1) });
// or just use Promise.resolve
Promise.resolve(1);
选项
¥Options
此规则采用一个选项，即对象，具有以下属性：
¥This rule takes one option, an object, with the following properties:
-
allowVoid：如果设置为true（默认为false），则此规则将允许返回空值。¥
allowVoid: If set totrue(falseby default), this rule will allow returning void values.
allowVoid
使用 { "allowVoid": true } 选项的此规则的正确代码示例：
¥Examples of correct code for this rule with the { "allowVoid": true } option:
/*eslint no-promise-executor-return: ["error", { allowVoid: true }]*/
new Promise((resolve, reject) => {
if (someCondition) {
return void resolve(defaultResult);
}
getSomething((err, result) => {
if (err) {
reject(err);
} else {
resolve(result);
}
});
});
new Promise((resolve, reject) => void getSomething((err, data) => {
if (err) {
reject(err);
} else {
resolve(data);
}
}));
new Promise(r => void r(1));
相关规则
版本
此规则是在 ESLint v7.3.0 中引入。