@putout/plugin-simplify-ternary/README.md

🐊Putout plugin adds ability to simplify ternary operator

# @putout/plugin-simplify-ternary [![NPM version][NPMIMGURL]][NPMURL]

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

> The **ternary** operator takes three operands: a condition followed by a question mark (`?`), then an expression to execute if the condition is truthy followed by a colon (`:`), and finally the expression to execute if the condition is falsy. This operator is frequently used as an alternative to an `if...else` statement.
>
> (c) [MDN](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Conditional_Operator)

🐊[**Putout**](https://github.com/coderaiser/putout) plugin adds ability to simplify **ternary** to **logical expression** when first and second operands are the same.

## Install

```
npm i @putout/plugin-simplify-ternary -D
```

## Rule

```json
{
    "rules": {
        "simplify-ternary/value": "on",
        "simplify-ternary/spread": "on"
    }
}
```

## value

Check out in 🐊[**Putout Editor**](https://putout.cloudcmd.io/#/gist/9dd4b87daa121c4fffbb63cab83b7f97/b90459bd06f8c7f71943791ee1bcb6970ade5a75).

### ❌ Example of incorrect code

```js
module.exports = fs.copyFileSync ? fs.copyFileSync : copyFileSync;

x = y ? y : z;
x = y ? z : y;
x = y ? z : false;

m = is ? a && b : a && c;
```

### ✅ Example of correct code

```js
module.exports = fs.copyFileSync || copyFileSync;

x = y || z;
x = y && z;

m = a && is ? b : c;
```

## spread

No need to use `ternary` when you can use logical expression (`&&`) it behaves in the same way, but simpler.

Check out in 🐊[**Putout Editor**](https://putout.cloudcmd.io/#/gist/8bbef76b11de45eb97e4f5647d9266bb/06840d9788ea4a2d48656331283f8da123d1e8fa).

### ❌ Example of incorrect code

```js
const a = {
    ...DEV ? {
        devtool: 'eval',
    } : {},
};
```

### ✅ Example of correct code

```js
const a = {
    ...DEV && {
        devtool: 'eval',
    },
};
```

## Comparison

Linter | Rule | Fix
--------|-------|------------|
🐊 **Putout**| [`simplify-ternary`](https://github.com/coderaiser/putout/tree/master/packages/plugin-simplify-ternary#readme)| ✅
⏣ **ESLint** | [`no-unneeded-ternary`](https://eslint.org/docs/rules/no-unneeded-ternary) | ⚠️ (partially: no [MemberExpression](https://github.com/coderaiser/putout/blob/master/docs/the-book-of-ast.md#memberexpression), [SpreadElement](https://github.com/coderaiser/putout/blob/master/docs/the-book-of-ast.md#spreadelement) support)

## License

MIT