prefer-flat-map.md

Prefer _.flatMap over consecutive _.map and _.flatten

When using _.map and _.flatten, it can be more concise to use _.flatMap instead.

Rule Details

This rule takes no arguments.

The following patterns are considered warnings:

_(a).map(f).flatten().value();

t = _.flatten(_.map(a, f));

The following patterns are not considered warnings:

t = _.map(a, f);

t = _.flatMap(a, f);

When Not To Use It

This rule is only relevant for Lodash 4. If you don't use Lodash 4, you should not use this rule.

If you do not want to enforce using _.flatMap, and prefer _.map and _.flatten instead, you should not use this rule.