no-unsafe-finally
禁止 finally
块中的控制流语句
配置文件 中的
"extends": "eslint:recommended"
属性启用了该规则
JavaScript 暂停 try
和 catch
块的控制流语句,直到 finally
块的执行完成。因此,当在 finally
中使用 return
、throw
、break
或 continue
时,try
和 catch
内部的控制流语句被覆盖,这被认为是意外行为。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; // 0 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
规则详情
此规则不允许 finally
块内的 return
、throw
、break
和 continue
语句。它允许间接使用,例如在 function
或 class
定义中。
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;
}
};
DzO9VpSFHJiTjGCgt1KSooNhAIn1o64th84QTOygwWSy7fBgj4TGxtI1vaW0J9Ta
/*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
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