no-unsafe-finally
"extends": "eslint:recommended"配置文件中的属性启用此规则。
JavaScript 挂起try和catch阻塞的控制流程语句，直到块的执行finally完成。所以，当return，throw，break，或continue在使用finally，内部控制流语句try和catch被覆盖，这被认为是意外的行为。如：
// We expect this function to return 1;
(() => {
try {
return 1; // 1 is returned but suspended until finally block ends
} catch(err) {
return 2;
} finally {
return 3; // 3 is returned before 1, which we did not expect
}
})();
// > 3// We expect this function to throw an error, then return
(() => {
try {
throw new Error("Try"); // error is thrown but suspended until finally block ends
} finally {
return 3; // 3 is returned before the error is thrown, which we did not expect
}
})();
// > 3// We expect this function to throw Try(...) error from the catch block
(() => {
try {
throw new Error("Try")
} catch(err) {
throw err; // The error thrown from try block is caught and rethrown
} finally {
throw new Error("Finally"); // Finally(...) is thrown, which we did not expect
}
})();
// > Uncaught Error: Finally(...)// We expect this function to return 0 from try block.
(() => {
label: try {
return 0; // 1 is returned but suspended until finally block ends
} finally {
break label; // It breaks out the try-finally block, before 0 is returned.
}
return 1;
})();
// > 1规则细节
这条规则不允许return，throw，break，和continue里面的语句finally块。它允许间接使用，如in function或class定义。
此规则的错误代码示例：
/*eslint no-unsafe-finally: "error"*/
let foo = function() {
try {
return 1;
} catch(err) {
return 2;
} finally {
return 3;
}
};/*eslint no-unsafe-finally: "error"*/
let foo = function() {
try {
return 1;
} catch(err) {
return 2;
} finally {
throw new Error;
}
};此规则的正确代码示例：
/*eslint no-unsafe-finally: "error"*/
let foo = function() {
try {
return 1;
} catch(err) {
return 2;
} finally {
console.log("hola!");
}
};/*eslint no-unsafe-finally: "error"*/
let foo = function() {
try {
return 1;
} catch(err) {
return 2;
} finally {
let a = function() {
return "hola!";
}
}
};/*eslint no-unsafe-finally: "error"*/
let foo = function(a) {
try {
return 1;
} catch(err) {
return 2;
} finally {
switch(a) {
case 1: {
console.log("hola!")
break;
}
}
}
};何时不使用它
如果您想允许finally块中的控制流操作，则可以关闭此规则。
版本
该规则在 ESLint 2.9.0 中引入。
资源
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