prefer-flat

Prefer Array.flat over spreading nested arrays into concat

Spreading nested arrays into concat manually performs one-level flattening.
Instead, you SHOULD call flat on the nested array.

- Category: style
- Level: warning
- Fix: suggestion
- Scope: module

Reported

function flatten(values: int32[][]): int32[] {
    return Array<int32>.new().concat(...values);
}
Accepted

function flatten(values: int32[][]): int32[] {
    return values.flat();
}
Prior art

- eslint-plugin-unicorn · prefer-array-flat

language/linter/src/rules/style/preferflat.rs:8