Enforce a maximum depth that callbacks can be nested
Many JavaScript libraries use the callback pattern to manage asynchronous operations. A program of any complexity will most likely need to manage several asynchronous operations at various levels of concurrency. A common pitfall that is easy to fall into is nesting callbacks, which makes code more difficult to read the deeper the callbacks are nested.
foo(function () {
bar(function () {
baz(function() {
qux(function () {
});
});
});
});
This rule enforces a maximum depth that callbacks can be nested to increase code clarity.
This rule has a number or object option:
"max"
(default 10
) enforces a maximum depth that callbacks can be nestedDeprecated: The object property maximum
is deprecated; please use the object property max
instead.
Examples of incorrect code for this rule with the { "max": 3 }
option:
/*eslint max-nested-callbacks: ["error", 3]*/
foo1(function() {
foo2(function() {
foo3(function() {
foo4(function() {
// Do something
});
});
});
});
Examples of correct code for this rule with the { "max": 3 }
option:
/*eslint max-nested-callbacks: ["error", 3]*/
foo1(handleFoo1);
function handleFoo1() {
foo2(handleFoo2);
}
function handleFoo2() {
foo3(handleFoo3);
}
function handleFoo3() {
foo4(handleFoo4);
}
function handleFoo4() {
foo5();
}
This rule was introduced in ESLint v0.2.0.
© OpenJS Foundation and other contributors
Licensed under the MIT License.
https://eslint.org/docs/latest/rules/max-nested-callbacks