test: mine a block in creative too, where nothing drops

tools/test_block_removal_parity.py only ever mined as a survival player:
every mine case ran ServerPlayerGameMode.destroyBlock in SURVIVAL, so the
creative branch (Player.preventsBlockDrops, no mined statistic, no tool
wear) was never compared even though game.rs::break_block_as_player splits
on it. Half the mine cases now run in creative, with a tool that can destroy
blocks in creative (a sword and a mace cannot, which the creative-mining
predicate corpus already owns).

VanillaDispenserOracle's Miner gains a creative flag (isCreative and
hasInfiniteMaterials) and the real CREATIVE game mode; the game's dispense
fixture sets the same mode for the case. --survival-only reproduces the
corpus as it was before this change.

4000/4000 cases match on the new corpus.

crates/horizon-client/src/game/dispense_fixture.rs

@@ -878,14 +878,19 @@ impl Game<'_> {
         Ok(Vec::new())
     }
 
-    /// A survival player three blocks south of `pos` mines it holding the
-    /// case's item (`break_block`, which every player's mining goes through):
-    /// the statistics and the held stack, as `VanillaDispenserOracle.mine`
-    /// prints them.
+    /// A player three blocks south of `pos` mines it holding the case's item
+    /// (`break_block`, which every player's mining goes through), in survival
+    /// or in creative, where the block and its contents never drop: the
+    /// statistics and the held stack, as `VanillaDispenserOracle.mine` prints
+    /// them.
     fn fixture_mine(&mut self, pos: BlockPos, op: &Value) -> Result<Vec<String>> {
         let stack = parse_stack(op["item"].as_str().unwrap_or("-"))?;
-        self.mode = GameMode::Survival;
-        self.creative = false;
+        self.mode = if op["creative"].as_bool().unwrap_or(false) {
+            GameMode::Creative
+        } else {
+            GameMode::Survival
+        };
+        self.creative = self.mode == GameMode::Creative;
         self.player = Some(PlayerMotion::new(
             self.motion,
             horizon_core::geometry::Vec3::new(

mods/horizon/src/test/java/dev/horizonlab/parity/VanillaDispenserOracle.java

@@ -193,10 +193,13 @@ public final class VanillaDispenserOracle {
     static List<String> mine(VanillaBlockUpdateOracle.World w, BlockPos pos, JsonObject op) throws Exception {
         Miner player = (Miner) VanillaBlockUpdateOracle.allocate.invoke(VanillaBlockUpdateOracle.unsafe, Miner.class);
         player.world = w;
+        player.creative = op.has("creative") && op.get("creative").getAsBoolean();
         player.hand = stack(op.get("item").getAsString());
         player.offhand = ItemStack.EMPTY;
         player.stats = new ArrayList<>();
-        VanillaBlockUpdateOracle.set(net.minecraft.world.entity.player.Player.class, player, "abilities", new net.minecraft.world.entity.player.Abilities());
+        var abilities = new net.minecraft.world.entity.player.Abilities();
+        abilities.invulnerable = abilities.instabuild = abilities.mayfly = player.creative;
+        VanillaBlockUpdateOracle.set(net.minecraft.world.entity.player.Player.class, player, "abilities", abilities);
         VanillaBlockUpdateOracle.set(net.minecraft.world.entity.player.Player.class, player, "foodData", new net.minecraft.world.food.FoodData());
         var advancements = (net.minecraft.server.PlayerAdvancements) VanillaBlockUpdateOracle.allocate.invoke(VanillaBlockUpdateOracle.unsafe, net.minecraft.server.PlayerAdvancements.class);
         VanillaBlockUpdateOracle.set(net.minecraft.server.PlayerAdvancements.class, advancements, "activeTriggers", new HashMap<>());
@@ -208,7 +211,7 @@ public final class VanillaDispenserOracle {
         player.setBoundingBox(EntityTypes.PLAYER.getDimensions().makeBoundingBox(at));
         var gameMode = new net.minecraft.server.level.ServerPlayerGameMode(player);
         VanillaBlockUpdateOracle.set(net.minecraft.server.level.ServerPlayerGameMode.class, gameMode, "gameModeForPlayer",
-            net.minecraft.world.level.GameType.SURVIVAL);
+            player.creative ? net.minecraft.world.level.GameType.CREATIVE : net.minecraft.world.level.GameType.SURVIVAL);
         gameMode.destroyBlock(pos);
         List<String> out = new ArrayList<>(player.stats);
         out.add("mine held " + ParityData.canon(player.hand));
@@ -218,14 +221,15 @@ public final class VanillaDispenserOracle {
     /** The player of a "mine" case: a survival `Clicker` whose selected inventory slot is its main hand. */
     static final class Miner extends net.minecraft.server.level.ServerPlayer {
         VanillaBlockUpdateOracle.World world;
+        boolean creative;
         ItemStack hand, offhand;
         List<String> stats;
         Miner() {
             super(null, null, null, null);
         }
         @Override public ServerLevel level() { return world; }
-        @Override public boolean hasInfiniteMaterials() { return false; }
-        @Override public boolean isCreative() { return false; }
+        @Override public boolean hasInfiniteMaterials() { return creative; }
+        @Override public boolean isCreative() { return creative; }
         @Override public boolean isSpectator() { return false; }
         @Override public EntityType<?> getType() { return EntityTypes.PLAYER; }
         @Override public net.minecraft.core.Holder<EntityType<?>> typeHolder() { return EntityTypes.PLAYER.builtInRegistryHolder(); }

tools/test_block_removal_parity.py

@@ -6,8 +6,11 @@ shelf, shulker box or another block entity holder at the origin holds random
 contents; the case then replaces it with `Level.setBlock` (another block, the
 same block in another state, with or without UPDATE_SKIP_BLOCK_ENTITY_SIDEEFFECTS),
 destroys it with `Level.destroyBlock` (with or without drops), removes it with
-`Level.removeBlock`, or a survival player mines it (`ServerPlayerGameMode.destroyBlock`,
-holding a tool or nothing, #844). Vanilla runs over the headless level of the dispenser oracle
+`Level.removeBlock`, or a player mines it (`ServerPlayerGameMode.destroyBlock`,
+holding a tool or nothing, #844): in survival, where the block's drops, the tool's wear and the
+mined statistic follow, and in creative, where the block itself never drops (a container's
+contents still spill) and no statistic is awarded. Vanilla runs over the headless level of the
+dispenser oracle
 (`VanillaDispenserOracle`, "remove" cases), which replays `LevelChunk.setBlockState`'s
 `BlockEntity.preRemoveSideEffects`; Horizon runs its game glue in a headless game
 (`HORIZON_DISPENSE_FIXTURE`). Both print the block changes, the contents left,
@@ -111,7 +114,7 @@ def other_state(states, rng, name, current):
     return rng.choice(choices) if choices else None
 
 
-def cases(facts, count, seed, only):
+def cases(facts, count, seed, only, creative=True):
     rng = random.Random(seed)
     states = d.States(facts)
     names = list(HOLDERS)
@@ -143,9 +146,23 @@ def cases(facts, count, seed, only):
         elif roll < 0.92:
             op = {'op': 'remove'}
         else:
-            # ServerPlayerGameMode.destroyBlock: a survival player mines it (#844). The tool comes
-            # from the roll, not another draw, so the cases after this one stay the same.
-            op = {'op': 'mine', 'item': TOOLS[int(roll * 1000) % len(TOOLS)]}
+            # ServerPlayerGameMode.destroyBlock: a player mines it (#844), in survival or, every
+            # other mine, in creative, where the block itself never drops and no statistic is
+            # awarded. The tool comes from the roll, not another draw, so the cases after this
+            # one stay the same.
+            item = TOOLS[int(roll * 1000) % len(TOOLS)]
+            if creative and n % 2 == 0:
+                # A sword or mace carries `can_destroy_blocks_in_creative: false`, so a creative
+                # player holding one cannot mine at all (`Item.canDestroyBlock`). That predicate
+                # has its own corpus (test_creative_mining_parity); these cases need a tool that
+                # does remove the block, and the empty hand does too.
+                if item in (plain('iron_sword'), plain('mace')):
+                    item = plain('diamond_pickaxe')
+                op = {'op': 'mine', 'item': item, 'creative': True}
+            else:
+                op = {'op': 'mine', 'item': item}
+                if creative:
+                    op['creative'] = False
         case = {**h.environment(rng), 'mode': 'remove', 'pos': [0, 0, 0], 'cells': cells, 'items': items, 'remove': op}
         case.pop('raining', None)
         case.pop('thundering', None)
@@ -162,6 +179,8 @@ def describe(case, facts):
 
 def main():
     parser = h.argument_parser(__doc__)
+    parser.add_argument('--survival-only', action='store_true',
+                        help='mine in survival only, as the corpus did before creative mining')
     args = parser.parse_args()
     if args.count == 40000:
         args.count = 4000
@@ -170,7 +189,7 @@ def main():
     resources = lab.LOCAL / 'horizon-client' / lock['minecraft']['version']
     work = lab.LOCAL / 'block-removal-parity'
     work.mkdir(parents=True, exist_ok=True)
-    all_cases = list(cases(facts, args.count, args.seed, args.only))
+    all_cases = list(cases(facts, args.count, args.seed, args.only, not args.survival_only))
     (work / 'cases.jsonl').write_text(''.join(json.dumps(case) + '\n' for case in all_cases))
     classes = work / 'classes'
     classes.mkdir(exist_ok=True)