@putout/plugin-extract-sequence-expressions/README.md

🐊Putout plugin adds ability to extract sequence expressions

# @putout/plugin-extract-sequence-expressions [![NPM version][NPMIMGURL]][NPMURL]

[NPMIMGURL]: https://img.shields.io/npm/v/@putout/plugin-extract-sequence-expressions.svg?style=flat&longCache=true
[NPMURL]: https://npmjs.org/package/@putout/plugin-extract-sequence-expressions"npm"

> The comma operator (`,`) evaluates each of its operands (from left to right) and returns the value of the last operand. This lets you create a compound expression in which multiple expressions are evaluated, with the compound expression's final value being the value of the rightmost of its member expressions.
>
> (c) [MDN](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Comma_Operator)

🐊[**Putout**](https://github.com/coderaiser/putout) plugin adds ability to extract **sequence expressions**. Check out in 🐊[**Putout Editor**](https://putout.cloudcmd.io/#/gist/785d072fc20d0a3854f6ced093918b06/483b359357ebc04232f4a321bd3db627dc6a15cb).

☝️*Remember, when you [writing a transform](https://github.com/coderaiser/putout/tree/master/packages/engine-runner#readme) you can skip all parts related to **extracting sequence expressions** and just reuse current **plugin** it will make your code simpler and less error prone.*

## Install

```
npm i @putout/plugin-extract-sequence-expressions -D
```

## Rule

```json
{
    "rules": {
        "extract-sequence-expressions": "on"
    }
}
```

## ❌ Example of incorrect code

```js
(module.exports.x = 1, module.exports.y = 2);

fn((a, b));
(fn(a), 'hello');

(fn(a), b = 3);
(fn(a), fn(b));

if ((a, b, c)) {}
```

## ✅ Example of correct code

```js
module.exports.x = 1;
module.exports.y = 2;

fn(a, b);
fn(a, 'hello');

fn(a);
b = 3;

fn(a);
fn(b);

a;
b;

if (c) {}
```

## Comparison

Linter | Rule | Fix
--------|-------|------------|
🐊 **Putout**| [`extract-sequence-expressions`](https://github.com/coderaiser/putout/tree/master/packages/plugin-extract-sequence-expressions#readme)| ✅
⏣ **ESLint** | [`no-sequences`](https://eslint.org/docs/rules/no-sequences) | ❌

## License

MIT