slabbed-broad-support-hook-rollout

name	slabbed-broad-support-hook-rollout
description	Safely expand slab support from one working object to more categories without regressions.

Slabbed — Broad Support Hook Rollout (Safe Expansion)

Goal

Expand from a single working object (e.g., torch) to a broader set while staying safe:

• keep strict visuals
• avoid regressions
• expand one category at a time
• tag each milestone

Non-goals

• “All items” in one leap
• Feature creep (stairs/fences/etc.) unless explicitly planned
• Performance tuning beyond basic sanity

Preconditions

• slabbed-first-placement-pass and ideally slabbed-first-survival-pass exist
• Repro world lanes exist
• ./gradlew build passes
• clean git status

Rollout order (recommended)

Expand in this order (lowest risk to higher):

1. Carpet
2. Pressure plates
3. Redstone dust
4. Repeaters / comparators
5. Rails
6. Plants (only after solid support semantics are proven)

If you must reorder, justify it in the report.

Method: expand by categories

For each category:

1. Identify the survival predicate(s) (usually canPlaceAt / neighbor update)
2. Identify placement predicate(s) (getPlacementState or item placement logic)
3. Prefer shared hook points over per-block when they’re clearly safe.
4. If shared points are risky, do targeted per-block mixins for that category only.

Strict commit slicing

• ONE category per branch
• ONE to TWO commits maximum:
  • feat: allow placement/support on slabs
  • fix: prevent pop-off on updates
• Tag after passing the category:
  • slabbed-<category>-pass (e.g., slabbed-carpet-pass)

Required tests per category

Use the test matrix skill, but only for:

• baseline full blocks lane
• bottom slab lane
• top slab lane

Run update triggers:

• neighbor update
• chunk unload/reload

Additionally:

• Redstone: power cycle it (lever adjacent full block ok)
• Rails: place straight, corner, slope attempt (slope may be invalid on slabs—record expected behavior)
• Plates: confirm entity activation still works (stand on it)

Regression gate (mandatory)

After each category passes:

• Re-run all previously passing categories quickly on slabs
• If any regression occurs:
  • revert to last tag
  • reduce scope (narrow injection or move to targeted mixin)

Output report format (required)

For each category:

• Category:
• Strategy (shared hook vs targeted mixins):
• Yarn targets touched:
• Files changed:
• Test summary (✅/❌ on bottom/top slabs):
• Commit hash + tag:

Stop conditions

• If a shared hook changes behavior for unrelated blocks: revert + switch to targeted mixin
• If strict visuals cannot be met: stop, document mismatch, and do not “ship ugly”
• If the rollout requires >3 new mixins for one category: pause and reassess architecture