JS.BASE.NO.FUNC.ASSIGN

Disallow reassigning 'function' declarations

JavaScript functions can be written as a FunctionDeclaration function foo() { ... } or as a FunctionExpression var foo = function() { ... };. While a JavaScript interpreter might tolerate it, overwriting/reassigning a function written as a FunctionDeclaration is often indicative of a mistake or issue.

Copy

function foo() {}
foo = bar;

Rule Details

This rule disallows reassigning function declarations.

Examples of incorrect code for this rule:

Copy

/*eslint no-func-assign: "error"*/

function foo() {}
foo = bar;

function foo() {
    foo = bar;
}

var a = function hello() {
  hello = 123;
};

Examples of incorrect code for this rule, unlike the corresponding rule in JSHint:

Copy

/*eslint no-func-assign: "error"*/

foo = bar;
function foo() {}

Examples of correct code for this rule:

Copy

/*eslint no-func-assign: "error"*/

var foo = function () {}
foo = bar;

function foo(foo) { // `foo` is shadowed.
    foo = bar;
}

function foo() {
    var foo = bar;  // `foo` is shadowed.
}