fix: #136 Add more robust block safety checks

build.gradle.kts

@@ -24,6 +24,7 @@ dependencies {
     detektPlugins(libs.detekt.ktlint)
     testImplementation(libs.mockk)
     testImplementation(libs.kotest.runner)
+    testImplementation(libs.kotest.datatest)
     testImplementation(libs.mockbukkit)
     testImplementation("io.papermc.paper:paper-api:$buildPaperVersion.build.+")
 }

gradle/libs.versions.toml

@@ -31,6 +31,7 @@ mysql-connector = { module = "com.mysql:mysql-connector-j", version.ref = "mysql
 detekt-ktlint = { module = "dev.detekt:detekt-rules-ktlint-wrapper", version.ref = "detekt" }
 mockk = { module = "io.mockk:mockk", version.ref = "mockk" }
 kotest-runner = { module = "io.kotest:kotest-runner-junit5", version.ref = "kotest" }
+kotest-datatest = { module = "io.kotest:kotest-framework-datatest", version.ref = "kotest" }
 mockbukkit = { module = "org.mockbukkit.mockbukkit:mockbukkit-v26.1.2", version.ref = "mockbukkit" }
 
 [plugins]

src/main/kotlin/xyz/atrius/waystones/data/config/property/SafeLiquidsProperty.kt

@@ -0,0 +1,17 @@
+package xyz.atrius.waystones.data.config.property
+
+import org.koin.core.annotation.Single
+import xyz.atrius.waystones.command.resolver.EnumArgumentType
+import xyz.atrius.waystones.data.config.ConfigProperty
+import xyz.atrius.waystones.data.config.property.type.SafeLiquids
+import xyz.atrius.waystones.utility.sanitizedStringFormat
+
+@Single(binds = [ConfigProperty::class])
+class SafeLiquidsProperty : ConfigProperty<SafeLiquids>(
+    property = "safe-liquids",
+    default = SafeLiquids.WATER,
+    parser = EnumArgumentType(SafeLiquids::class),
+    propertyType = SafeLiquids::class,
+    format = { it.sanitizedStringFormat() },
+    serialize = { it.name },
+)

src/main/kotlin/xyz/atrius/waystones/data/config/property/type/SafeLiquids.kt

@@ -0,0 +1,8 @@
+package xyz.atrius.waystones.data.config.property.type
+
+@Suppress("unused")
+enum class SafeLiquids {
+    NONE,
+    WATER,
+    ALL,
+}

src/main/kotlin/xyz/atrius/waystones/service/BlockSafetyService.kt

@@ -0,0 +1,54 @@
+package xyz.atrius.waystones.service
+
+import org.bukkit.Location
+import org.bukkit.Material
+import org.koin.core.annotation.Single
+import xyz.atrius.waystones.data.config.property.SafeLiquidsProperty
+import xyz.atrius.waystones.data.config.property.type.SafeLiquids
+import xyz.atrius.waystones.utility.UP
+
+@Single
+class BlockSafetyService(
+    private val safeLiquids: SafeLiquidsProperty,
+) {
+    // Blocks that are non-collidable but still hazardous to teleport into.
+    // These deal damage or apply harmful effects to entities occupying their space.
+    private val hazardBlocks = setOf(
+        Material.FIRE,
+        Material.SOUL_FIRE,
+        Material.CAMPFIRE,
+        Material.SOUL_CAMPFIRE,
+        Material.SWEET_BERRY_BUSH,
+        Material.WITHER_ROSE,
+    )
+
+    fun isLocationSafe(waystone: Location): Boolean {
+        val feet = waystone.UP
+        val head = feet.UP
+        // Check the two blocks above the waystone (head and feet clearance).
+        // Uses isCollidable which reflects actual entity collision geometry,
+        // unlike isSolid which incorrectly marks signs/pressure plates as solid.
+        return checkBlock(feet) &&
+            checkBlock(head)
+    }
+
+    private fun checkBlock(checkLocation: Location): Boolean {
+        val block = checkLocation.world
+            ?.getBlockAt(checkLocation)
+            ?: return false
+        val material = block.type
+        // Physical obstruction check: catches doors, potted plants, fences,
+        // redstone components with physical presence, all full blocks,
+        // and any blocks that may cause damage to the player
+        if (block.isCollidable || material in hazardBlocks) {
+            return false
+        }
+        // Liquid check: configurable via safe-liquids property.
+        // Liquids have no collision but can still be dangerous or undesirable to land in.
+        return when (material) {
+            Material.LAVA -> safeLiquids.value() == SafeLiquids.ALL
+            Material.WATER -> safeLiquids.value() != SafeLiquids.NONE
+            else -> true
+        }
+    }
+}

src/main/kotlin/xyz/atrius/waystones/service/WaystoneService.kt

@@ -26,7 +26,6 @@ import xyz.atrius.waystones.manager.LocalizationManager
 import xyz.atrius.waystones.manager.LocalizedString
 import xyz.atrius.waystones.repository.WaystoneInfoRepository
 import xyz.atrius.waystones.utility.isActive
-import xyz.atrius.waystones.utility.isSafe
 import xyz.atrius.waystones.utility.powerBlock
 import xyz.atrius.waystones.utility.sameDimension
 
@@ -45,6 +44,7 @@ class WaystoneService(
     private val worldRatioService: WorldRatioService,
     private val limitDistance: LimitDistanceProperty,
     private val waystoneInfoRepository: WaystoneInfoRepository,
+    private val blockSafetyService: BlockSafetyService,
 ) {
 
     fun process(player: Player, block: Block, keyLocation: Location): Either<WaystoneServiceError, Warp> = either {
@@ -209,7 +209,7 @@ class WaystoneService(
             return WaystoneStatus.Unpowered(localization)
         }
 
-        if (!block.location.isSafe) {
+        if (!blockSafetyService.isLocationSafe(block.location)) {
             return WaystoneStatus.Obstructed(localization)
         }
 

src/main/kotlin/xyz/atrius/waystones/utility/Location.kt

@@ -44,18 +44,6 @@ val Location.neighbors: List<Location>
 val Location.locationCode
     get() = "${world?.name}@$blockX:$blockY:$blockZ"
 
-// Determines if the selected block is safe to spawn on
-val Location.isSafe: Boolean
-    get() = !listOf(UP, UP.UP)
-        .map {
-            world
-                ?.getBlockAt(it)
-                ?.type
-                ?.isSolid
-                ?: true
-        }
-        .any { it }
-
 fun Location.rotateY(angle: Double, amp: Double = 1.0) = add(
     Vector(
         cos(angle) * amp,

src/main/resources/config.yml

@@ -19,6 +19,7 @@ relinkable-keys: true
 enable-key-items: true
 enable-advancements: true
 show-compass-coordinates: true
+safe-liquids: WATER
 key-recipe:
   - AIR
   - IRON_INGOT

src/main/resources/locale-en.yml

@@ -94,6 +94,7 @@ property-warp-animations-info: "Whether to use particle animations while warping
 property-default-world-ratio-info: "The world ratio to use for worlds which have no ratio set"
 property-base-distance-info: "The baseline for which all waystones are given as a minimum teleport distance"
 property-show-compass-coordinates-info: "Whether to show waystone coordinates in the compass lore upon linking"
+property-safe-liquids-info: "Determines which liquids are considered safe when obstructing a waystone"
 default-subcommand-desc: "No description provided"
 ws-ratio-subcommand-desc: "Adjust the warp distance ratios between worlds"
 ws-reload-subcommand-desc: "Reload aspects of the plugin"