# Prefer _.some

When comparing the index of an item with an `findIndex` method, it can be more expressive to use `_.some`, when only the sole existence of a matching item is taken into account.

## Rule Details

This rule takes one argument - an options object, with the property `includeNative`. If true, the rule will report on all `findIndex`, and if false, it will only report on `_.indexOf` calls.

The following patterns are considered warnings:

```js
var a = _.findIndex(b, f) === -1

var a = _.findIndex(b, f) >= 0
```

```js
/*eslint lodash/prefer-some: [2, {"includeNative": true}]*/
if (a.findIndex(f) === -1) {
 // ...
}
```

The following patterns are not considered warnings:

```js
x = _.findIndex(a, f);

_.findIndex(a, f) === 2;

if (_.some(a, f)) {
 // ...
}
```


## When Not To Use It

If you do not want to enforce using `_.findIndex`, you should not use this rule.