import { tmpdir } from 'node:os';
import { join } from 'node:path';

/**
 * The neutral database path the test preload arms `CELILO_DB_PATH` with
 * (celilo#1315). The file does not exist, so a reader falls into whatever
 * "no database" branch its feature has — and no test ever opens the
 * operator's real `~/Library/.../celilo.db`, which is what a suite that
 * reads the variable without setting it would otherwise reach.
 *
 * Why teardowns RESET to this path instead of `delete`: bunfig's `[test]`
 * preload runs ONCE PER PROCESS, not once per test file. A teardown that
 * clears the variable leaves every later var-less reader on the real
 * database for the rest of the run. Resetting to the scratch path keeps the
 * preload's invariant standing from the first test to the last.
 */
export const SCRATCH_DB_PATH = join(tmpdir(), 'celilo-test-absent.db');

/**
 * Point `CELILO_DB_PATH` at the neutral scratch path. Call from a test's
 * afterEach (or any teardown) that pointed the variable somewhere else.
 */
export function resetTestDbPath(): void {
  process.env.CELILO_DB_PATH = SCRATCH_DB_PATH;
}