PreFlight — Scene Smoke Tester for Godot 4

Green tests but gray screen? Never again.

We shipped a game with a fully green unit-test suite — and it booted to a gray screen on device. Two parse errors had kept the view from ever loading. Logic tests can't catch that class of bug. So we built the tool that does.

What PreFlight does

- Boots every .tscn in your project, each in its own child process — a crashing scene can never take down the run or your editor.

- Catches what unit tests don't see: parse errors, dead resource paths, instantiation failures, runtime errors in the first frames, hangs (killed after a timeout you control) and — in visual mode — scenes that render nothing, with a screenshot per scene.

- One click in a bottom-panel dock, or one command in CI — the exit code is the number of failing scenes, ready for GitHub Actions.

- Writes a clean HTML + JSON report.

- Zero configuration. No test scripts to write or maintain.

What PreFlight is not: a unit-test framework (use GUT/GdUnit4 for logic) and not a screenshot-diffing tool. It answers exactly one question, before your players do: does every scene in this build actually load?

Requirements: Godot 4.2+ (built on 4.6). macOS/Linux fully supported; on Windows, hang-timeouts are best-effort in v1.