Slabbed — Test Matrix + Repro World (Strict)

Goal

Create a consistent, repeatable way to validate Slabbed:

• •placement works on slab tops
• •blocks do not pop off after updates
• •visuals are correct (strict)

This skill produces a concrete test matrix and a simple “repro world” build plan.

Non-goals

• •No mixin code changes required
• •No performance optimization here
• •No broad QA; focus on slab-support behaviors

Assumptions

• •MC 1.21.11 Fabric dev run is working
• •Rule: treat the top face of slabs as ground (bottom slab top and top slab top)

A) Standard Repro World Setup

1) World settings

• •Create new singleplayer world: Slabbed QA
• •Creative mode
• •Cheats: ON
• •Flat world preset (superflat) preferred for clarity
• •Time: set day and lock if desired

2) Build the Repro Platform (coords-based)

At spawn, build a labeled platform with 3 lanes:

Lane 1: Full blocks baseline
Lane 2: Bottom slabs (target behavior)
Lane 3: Top slabs (target behavior)

Each lane should be 3 blocks wide and at least 30 blocks long.

3) Segment markers

Every 5 blocks, place a sign label:

• •T1 Torch
• •T2 Redstone Dust
• •T3 Repeater/Comparator
• •T4 Rails
• •T5 Pressure Plates
• •T6 Carpet
• •T7 Plants (optional)
• •T8 Misc (as needed)

B) Test Matrix (Strict)

For each test item, run in each lane (full / bottom slab / top slab) and record PASS/FAIL.

Common pass criteria (all)

• •Places without forcing weird aim hacks
• •Renders at the correct height (flush to slab top surface)
• •Does not instantly break
• •Survives a neighbor update and chunk reload

Evidence capture

For every FAIL:

• •Screenshot showing placement + block state context
• •Save the exact reproduction steps in a note For every PASS (first time per category):
• •One screenshot

C) Update/Stress Actions (run after placement)

After placing each item, run these update triggers:

1. •Neighbor update

• •Place and break a block adjacent (side)
• •Place and break a block beneath (where applicable)

1. •Chunk unload/reload

• •Fly 200 blocks away, return

1. •Fluid interaction (if relevant)

• •Place water adjacent (if item normally interacts)

1. •Redstone tick (redstone category)

• •Power it and observe updates (lever on adjacent full block is acceptable for test)

1. •Piston test (if relevant)

• •Push a neighboring full block to cause updates (don’t require the slabbed item itself to be pushable)

D) Output format (required)

Produce a test report in this exact structure:

• •Build/commit under test: <hash or local>
• •World: Slabbed QA
• •Results:
  • •Torch: Full / BottomSlab / TopSlab
  • •Dust: ...
  • •Repeater: ...
  • •Comparator: ...
  • •Rails: ...
  • •Pressure plates: ...
  • •Carpet: ...
• •Notable failures (each):
  • •What broke
  • •Exact placement context
  • •Which update trigger caused it
  • •Screenshot filenames/paths
• •Next debug targets:
  • •1–3 suspected methods/classes

E) Stop conditions

If any category fails on slabs:

• •Do not expand scope
• •Pivot immediately to diagnosis using slabbed-mixin-target-discovery

Pass criteria for “Alpha Ready”

• •Torch, Dust, Repeater/Comparator, Rails, Pressure Plates, Carpet:
  • •PASS on bottom slabs and top slabs
  • •Survive neighbor updates + chunk reload
  • •Visual height is correct (strict)