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no-func-assign

Disallow reassigning function declarations

βœ… Recommended

The "extends": "eslint:recommended" property in a configuration file enables this rule

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.

function foo() {}
foo = bar;

Rule Details

This rule disallows reassigning function declarations.

Examples of incorrect code for this rule:

/*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:

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

foo = bar;
function foo() {}

Examples of correct code for this rule:

/*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.
}

Version

This rule was introduced in ESLint v0.0.9.

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