unicorn/prefer-array-flat-map Perf

🛠️ An auto-fix is available for this rule.

What it does

Prefers the use of .flatMap() when map().flat() are used together.

Why is this bad?

It is slightly more efficient to use .flatMap(…) instead of .map(…).flat().

Examples

Examples of incorrect code for this rule:

const bar = [1, 2, 3].map(i => [i]).flat();

Examples of correct code for this rule:

const bar = [1, 2, 3].flatMap(i => [i]);

How to use

To enable this rule using the config file or in the CLI, you can use:

Config (.oxlintrc.json)

{
  "rules": {
    "unicorn/prefer-array-flat-map": "error"
  }
}

CLI

oxlint --deny unicorn/prefer-array-flat-map

References

• Rule Source