unnecessary-filter-map

Disallow filterMap callbacks with a definitely defined result

A filterMap callback with a definitely defined result cannot filter any element.
Instead, you SHOULD call map to express the unconditional transformation.

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

Reported

function increment(values: int32[]): int32[] {
    return values.filterMap((value) => value + 1);
}
Accepted

function increment(values: int32[]): int32[] {
    return values.map((value) => value + 1);
}
Prior art

- Clippy · unnecessaryfiltermap

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