import { defineConfig } from "vitest/config";
import path from "node:path";

export default defineConfig({
  resolve: {
    alias: {
      "@": path.resolve(__dirname, "./src"),
    },
  },
  test: {
    environment: "node",
    // Scope explicitly to this repo's own tests/ dir — without this, Vitest's
    // default glob also picks up any stray sibling git worktree checked out
    // under .claude/worktrees/ (e.g. worktree-ui-basic), which isn't excluded
    // by Vitest's defaults since those only skip node_modules/.git/etc, not
    // .claude/. A stray worktree's stale test file still resolves the "@"
    // alias to *this* repo's src/ (see resolve.alias above, which is
    // __dirname-relative), so it silently runs old tests against current
    // code under a shared identity — confirmed happening in practice once a
    // second worktree existed.
    include: ["tests/**/*.test.ts"],
    setupFiles: ["./tests/setup.ts"],
    // Each test file spins up its own throwaway Postgres database by
    // mutating process.env.DATABASE_URL in tests/setup.ts's beforeAll (see
    // that file). That per-file DB switch is not safe under Vitest's default
    // parallel file execution: two files' beforeAll/query timing can
    // interleave such that both end up issuing real queries against the
    // same throwaway DB (confirmed empirically once Request gained a real
    // FK to Employee — tests/employees.test.ts and tests/requests.test.ts
    // started intermittently deleting/reading each other's rows, causing
    // spurious FK-violation and row-count failures that disappear when run
    // sequentially). Disabling file parallelism trades a bit of wall-clock
    // test time for correctness — each file's throwaway DB is now genuinely
    // private for the duration of that file's run.
    fileParallelism: false,
  },
});