{
  "name": "lava_plus_water_makes_steam",
  "description": "Lava and water adjacent should produce steam and stone",
  "seed": 42,
  "init_mode": "empty",
  "setup": [
    {"type": "fill_rect", "x": 100, "y": 120, "w": 20, "h": 1, "material": "stone"},
    {"type": "fill_rect", "x": 100, "y": 95, "w": 20, "h": 1, "material": "stone"},
    {"type": "fill_rect", "x": 102, "y": 112, "w": 4, "h": 4, "material": "lava"},
    {"type": "fill_rect", "x": 107, "y": 112, "w": 4, "h": 4, "material": "water"}
  ],
  "steps": 60,
  "assertions": [
    {"type": "material_count_in_region", "x": 100, "y": 100, "w": 20, "h": 20, "material": "steam", "min": 1, "max": 30}
  ]
}