---
url: /docs/guide/usage/linter/rules/eslint/no-self-assign.md
---

### What it does

Disallow assignments where both sides are exactly the same.

### Why is this bad?

Self assignments have no effect, so probably those are an error due to incomplete
refactoring. Those indicate that what you should do is still remaining.

### Examples

Examples of **incorrect** code for this rule:

```javascript
foo = foo;

[a, b] = [a, b];
[a, ...b] = [x, ...b];

({ a, b } = { a, x });

foo &&= foo;
foo ||= foo;
foo ??= foo;
```

```javascript
obj.a = obj.a;
obj.a.b = obj.a.b;
obj["a"] = obj["a"];
obj[a] = obj[a];
```

Examples of **correct** code for this rule:

```javascript
foo = bar;
[a, b] = [b, a];

// This pattern is warned by the `no-use-before-define` rule.
let foo = foo;

// The default values have an effect.
[foo = 1] = [foo];

// This ignores if there is a function call.
obj.a().b = obj.a().b;
a().b = a().b;

// `&=` and `|=` have an effect on non-integers.
foo &= foo;
foo |= foo;
```

## Configuration

This rule accepts a configuration object with the following properties:

### props

type: `boolean`

default: `true`

The `props` option when set to `false`, disables the checking of properties.

With `props` set to `false` the following are examples of correct code:

```javascript
obj.a = obj.a;
obj.a.b = obj.a.b;
obj["a"] = obj["a"];
obj[a] = obj[a];
```

## How to use

## Version

This rule was added in v0.0.5.

## References