Chunk: make all parameters of __construct() mandatory and non-nullable

having the constructor fill in defaults for these invariably causes bugs.

src/world/format/Chunk.php

@@ -68,7 +68,7 @@ class Chunk{
 	/**
 	 * @param SubChunk[] $subChunks
 	 */
-	public function __construct(array $subChunks = [], ?BiomeArray $biomeIds = null, bool $terrainPopulated = false){
+	public function __construct(array $subChunks, BiomeArray $biomeIds, bool $terrainPopulated){
 		$this->subChunks = new \SplFixedArray(Chunk::MAX_SUBCHUNKS);
 
 		foreach($this->subChunks as $y => $null){
@@ -77,7 +77,7 @@ class Chunk{
 
 		$val = ($this->subChunks->getSize() * SubChunk::EDGE_LENGTH);
 		$this->heightMap = HeightArray::fill($val); //TODO: what about lazily initializing this?
-		$this->biomeIds = $biomeIds ?? BiomeArray::fill(BiomeIds::OCEAN);
+		$this->biomeIds = $biomeIds;
 
 		$this->terrainPopulated = $terrainPopulated;
 	}

src/world/format/io/leveldb/LevelDB.php

@@ -25,6 +25,7 @@ namespace pocketmine\world\format\io\leveldb;
 
 use pocketmine\block\Block;
 use pocketmine\block\BlockLegacyIds;
+use pocketmine\data\bedrock\BiomeIds;
 use pocketmine\data\bedrock\LegacyBlockIdToStringIdMap;
 use pocketmine\nbt\LittleEndianNbtSerializer;
 use pocketmine\nbt\NbtDataException;
@@ -416,7 +417,7 @@ class LevelDB extends BaseWorldProvider implements WritableWorldProvider{
 
 		$chunk = new Chunk(
 			$subChunks,
-			$biomeArray,
+			$biomeArray ?? BiomeArray::fill(BiomeIds::OCEAN), //TODO: maybe missing biomes should be an error?
 			$terrainPopulated
 		);
 

src/world/format/io/region/LegacyAnvilChunkTrait.php

@@ -23,6 +23,7 @@ declare(strict_types=1);
 
 namespace pocketmine\world\format\io\region;
 
+use pocketmine\data\bedrock\BiomeIds;
 use pocketmine\nbt\BigEndianNbtSerializer;
 use pocketmine\nbt\NbtDataException;
 use pocketmine\nbt\tag\ByteArrayTag;
@@ -86,6 +87,8 @@ trait LegacyAnvilChunkTrait{
 			$biomeArray = $makeBiomeArray(ChunkUtils::convertBiomeColors($biomeColorsTag->getValue())); //Convert back to original format
 		}elseif(($biomesTag = $chunk->getTag("Biomes")) instanceof ByteArrayTag){
 			$biomeArray = $makeBiomeArray($biomesTag->getValue());
+		}else{
+			$biomeArray = BiomeArray::fill(BiomeIds::OCEAN);
 		}
 
 		return new ChunkData(

src/world/format/io/region/McRegion.php

@@ -25,6 +25,7 @@ namespace pocketmine\world\format\io\region;
 
 use pocketmine\block\Block;
 use pocketmine\block\BlockLegacyIds;
+use pocketmine\data\bedrock\BiomeIds;
 use pocketmine\nbt\BigEndianNbtSerializer;
 use pocketmine\nbt\NbtDataException;
 use pocketmine\nbt\tag\ByteArrayTag;
@@ -80,6 +81,8 @@ class McRegion extends RegionWorldProvider{
 			$biomeIds = $makeBiomeArray(ChunkUtils::convertBiomeColors($biomeColorsTag->getValue())); //Convert back to original format
 		}elseif(($biomesTag = $chunk->getTag("Biomes")) instanceof ByteArrayTag){
 			$biomeIds = $makeBiomeArray($biomesTag->getValue());
+		}else{
+			$biomeIds = BiomeArray::fill(BiomeIds::OCEAN);
 		}
 
 		return new ChunkData(

src/world/generator/Flat.php

@@ -69,7 +69,7 @@ class Flat extends Generator{
 	}
 
 	protected function generateBaseChunk() : void{
-		$this->chunk = new Chunk([], BiomeArray::fill($this->options->getBiomeId()));
+		$this->chunk = new Chunk([], BiomeArray::fill($this->options->getBiomeId()), false);
 
 		$structure = $this->options->getStructure();
 		$count = count($structure);

src/world/generator/PopulationTask.php

@@ -23,8 +23,10 @@ declare(strict_types=1);
 
 namespace pocketmine\world\generator;
 
+use pocketmine\data\bedrock\BiomeIds;
 use pocketmine\scheduler\AsyncTask;
 use pocketmine\utils\AssumptionFailedError;
+use pocketmine\world\format\BiomeArray;
 use pocketmine\world\format\Chunk;
 use pocketmine\world\format\io\FastChunkSerializer;
 use pocketmine\world\SimpleChunkManager;
@@ -127,7 +129,7 @@ class PopulationTask extends AsyncTask{
 	}
 
 	private static function setOrGenerateChunk(SimpleChunkManager $manager, Generator $generator, int $chunkX, int $chunkZ, ?Chunk $chunk) : Chunk{
-		$manager->setChunk($chunkX, $chunkZ, $chunk ?? new Chunk());
+		$manager->setChunk($chunkX, $chunkZ, $chunk ?? new Chunk([], BiomeArray::fill(BiomeIds::OCEAN), false));
 		if($chunk === null){
 			$generator->generateChunk($manager, $chunkX, $chunkZ);
 			$chunk = $manager->getChunk($chunkX, $chunkZ);

tests/phpunit/world/format/ChunkTest.php

@@ -24,11 +24,12 @@ declare(strict_types=1);
 namespace pocketmine\world\format;
 
 use PHPUnit\Framework\TestCase;
+use pocketmine\data\bedrock\BiomeIds;
 
 class ChunkTest extends TestCase{
 
 	public function testClone() : void{
-		$chunk = new Chunk();
+		$chunk = new Chunk([], BiomeArray::fill(BiomeIds::OCEAN), false);
 		$chunk->setFullBlock(0, 0, 0, 1);
 		$chunk->setBiomeId(0, 0, 1);
 		$chunk->setHeightMap(0, 0, 1);