migrate

name	migrate
description	Update a game's code after a BLIT386 upgrade renamed parts of the API. Use this when 'blit upgrade' or 'blit migrate' reports names that need a closer look, when the game breaks after updating BLIT386, or when the user says 'update my game to the new version' or 'fix the renamed functions'.

Update BLIT386 API names

Update a game after a BLIT386 upgrade renamed parts of the API: let blit migrate make the safe renames, then handle the rest by hand.

When to use

Use when blit upgrade or blit migrate reports names that "need a closer look," when the game breaks after a BLIT386 update, or when the user says "update my game to the new version" or "fix the renamed functions."

Steps

1. Preview first: run npx blit migrate. It lists the renames it can make automatically and the ones that need review. Nothing is written yet.
2. Apply the safe ones: run npx blit migrate --write. This rewrites unambiguous names for you (for example BT.buttonDown -> BT.isDown, the overlayEnabled config flag -> isOverlayEnabled).
3. Handle each "needs a closer look" item by hand. These are common words, so the tool will not rewrite them blindly - they might belong to your own code. Only rename a call when the value on the left is the matching BLIT386 type:
   • .equals(...) -> .isEqual(...) on a Vector2i, Rect2i, or Color32
   • .contains(...) -> .isContaining(...) on a Rect2i
   • .intersects(...) -> .isIntersecting(...) on a Rect2i
   • .tick(...) -> .fireIfElapsed(...) on a Timer
   • Inside the bootstrap(...) options object only: canvasId -> canvasID, containerId -> containerID, waitForDOMReady -> isWaitingForDOMReady
4. Leave anything that is not a BLIT386 value alone. A plain array's .contains(...) or your own tick() method is not the engine – do not touch it.
5. Verify: run npx blit run and play the game, or npx blit doctor to check the setup. If something still breaks, use the "fix" skill.

Notes

• The full, authoritative list of old -> new names is the engine's deprecation timeline: https://blit386.dev/docs/reference/deprecations
• blit migrate previews by default and only changes files with --write, so it is always safe to run and read first.
• If the project is not saved with git, save a copy before writing – blit migrate --write warns about this first.