slabbed-neighbor-update-map

name	slabbed-neighbor-update-map
description	Map and validate the neighbor update and revalidation paths that cause slab-supported objects to pop off, per category.

Slabbed — Neighbor Update Map

Goal

Maintain a living map of the update paths that can invalidate placement and cause pop-offs. Use this to prevent “it places but later breaks” regressions.

When to run

• When a category places correctly but breaks later
• After changing any survival predicate hook
• Before tagging slabbed-<category>-pass for update-sensitive categories (redstone, rails, plants)

Update trigger catalog

For each category under test, explicitly test these triggers and record PASS/FAIL:

1) Below block change

• Break the supporting slab
• Replace supporting slab with a different slab type (bottom ↔ top)
• Replace slab with full block and back

2) Adjacent block change (horizontal)

• Place a full block next to the object
• Break that adjacent block
• Repeat on all four sides if shape/connection matters

3) Above block change

• Place a block above (if possible)
• Remove it This matters for some plants/stacking logic.

4) Scheduled tick / random tick

• If the block uses ticking logic, wait and observe
• For plants, use bone meal if relevant and observe stability

5) Fluid update adjacency

• Place water adjacent
• Remove water
• If waterlogging is relevant, test that explicitly

6) Redstone neighbor propagation (if relevant)

• Toggle a nearby power source
• Observe whether revalidation happens and whether the object survives

7) Piston-induced updates (optional but useful)

• Push/pull an adjacent full block to create neighbor updates
• Do not require the supported object itself to be moved

8) Chunk unload/reload

• Fly far enough to unload chunk
• Return and confirm it is still present

How to build the map

For each category, fill in:

• Category:
• Placement predicate location (Yarn):
• Survival predicate location (Yarn):
• Triggers that caused revalidation:
• Triggers that caused failure:
• Best hook point to intercept revalidation:
• Notes on strict visuals impact:

Output format (required)

• Category:
• Full lane: PASS/FAIL
• Bottom slab lane: PASS/FAIL
• Top slab lane: PASS/FAIL
• Failures:
  • Trigger:
  • What broke:
  • Repro steps:
• Suspected hook target(s) (Yarn class and method):
• Next change proposed (one sentence):

Stop conditions

• If failures differ by trigger type, do not “patch randomly”
• First identify the exact survival recheck path and only then change hooks
• If a shared hook fixes one category but breaks another, revert and go targeted