True when this run selects a subset of the tests inside the files it loads.

File-level narrowing (--only-failed, --changed) does not count: those run whole files, so their timings stay representative and their failure set is complete for the files they ran. A test-level filter breaks both, which is why the timing and failure caches skip filtered runs.

lineTargets counts even before it resolves to selectors — it is read on the parent config, where per-group selectors are not visible.

import * as RunState from '../setup/run-state.ts';

const state = RunState.create();
isFilteredRun({ state }); // false — whole files, caches stay valid
isFilteredRun({ filter: 'cart', state }); // true — a test-level subset