Close Collection before process.exit() to prevent Windows libuv assertion crash

[HeyItsGilbert]

Problem

On Windows, running any command that opens a Collection (e.g. mdbase types create reviews) triggers a libuv assertion failure on exit:

Assertion failed: !(handle->flags & UV_HANDLE_CLOSING), file src\win\async.c, line 76

This happens because Collection.open() initializes an in-memory sql.js/WASM SQLite database with prepared statements. When process.exit() is called without first closing the collection, Node tears down the event loop while these handles are still active. On Linux/macOS this is silently ignored; on Windows, libuv's stricter handle lifecycle checking triggers a fatal assertion.

Root Cause

Every command that calls Collection.open() was calling process.exit(N) directly without first calling collection.close(). The close() method flushes the SQLite cache to disk, frees prepared statements, and closes the database — all necessary for a clean shutdown.

Only collections files had proper cleanup via try/finally with await collection.close().

Solution

1. Added closeAndExit() utility in utils.ts — a helper that gracefully closes a Collection (if provided) then calls process.exit().

2. Replaced ~70 bare process.exit() calls across all 16 command files that open a Collection:

   • types.ts (the reported crash site)
   • create.ts
   • update.ts
   • read.ts
   • delete.ts
   • rename.ts
   • query.ts
   • validate.ts
   • lint.ts
   • fmt.ts
   • diff.ts
   • stats.ts
   • export.ts
   • import.ts
   • graph.ts
   • schema.ts
   • base.ts
   • watch.ts (cleanup handler)

3. process.exit() calls before any Collection is opened (e.g. in init, collections, early argument validation) are left unchanged — they have no handles to clean up.

Secondary benefit

Beyond fixing the Windows crash, this also ensures the SQLite cache is properly flushed to disk on every exit path. Previously, cache updates from mutations (create, update, delete, rename, createType, import, lint --fix, fmt) were silently lost because the in-memory database was never written back.

How closeAndExit works

export async function closeAndExit(
  collection: { close(): Promise<void> } | null | undefined,
  code: number,
): Promise<never> {
  if (collection) {
    try {
      await collection.close();
    } catch {
      // Ignore cleanup errors — we're exiting anyway.
    }
  }
  process.exit(code);
}

Note

Tests that spawn the CLI via execFileSync may need timeout adjustments since collection.close() adds a small amount of async work before exit. The existing 30s testTimeout in vitest.config.ts should be sufficient.

Fixes #3

[HeyItsGilbert]

Pulled from Codespace to my local machine (and had to add the latest commit) but here's a screenshot of it working on my windows laptop now.