fix: Handle exceptions in coroutine scope dialogs (#25)

api/src/main/resources/assets/sheeplib/lang/en_us.json

@@ -9,5 +9,6 @@
   "sheeplib.progress.complete": "Complete",
   "sheeplib.progress.failed": "Failed",
 
-  "sheeplib.error": "[SheepLib] An error occurred while opening a dialog.\nCheck your game log for more information."
+  "sheeplib.error": "[SheepLib] An error occurred while opening a dialog.\nCheck your game log for more information.",
+  "sheeplib.error.coroutine": "[SheepLib] An error occurred in a dialog, so it was closed.\nCheck your game log for more information."
 }

coroutines/src/main/kotlin/com/noxcrew/sheeplib/coroutines/CoroutineScopeDialog.kt

@@ -3,24 +3,40 @@ package com.noxcrew.sheeplib.coroutines
 import com.noxcrew.sheeplib.dialog.Dialog
 import kotlinx.coroutines.CancellationException
 import kotlinx.coroutines.CoroutineDispatcher
+import kotlinx.coroutines.CoroutineExceptionHandler
 import kotlinx.coroutines.CoroutineName
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.SupervisorJob
 import kotlinx.coroutines.cancel
+import net.minecraft.ChatFormatting
+import net.minecraft.client.Minecraft
+import net.minecraft.network.chat.Component
 import org.jetbrains.annotations.ApiStatus
 import org.jetbrains.annotations.MustBeInvokedByOverriders
+import org.slf4j.LoggerFactory
 import kotlin.coroutines.CoroutineContext
+import kotlin.reflect.jvm.jvmName
 
 /** A dialog with its own [CoroutineContext], which is cancelled when the dialog is closed. */
 @ApiStatus.Experimental
 public abstract class CoroutineScopeDialog(
     x: Int,
     y: Int,
-    dispatcher: CoroutineDispatcher = MinecraftDispatchers.Background
+    dispatcher: CoroutineDispatcher = MinecraftDispatchers.Background,
 ) : Dialog(x, y),
     CoroutineScope {
-
-    override val coroutineContext: CoroutineContext by lazy { SupervisorJob() + CoroutineName("$this") + dispatcher }
+    override val coroutineContext: CoroutineContext by lazy {
+        SupervisorJob() +
+                CoroutineName("$this") +
+                dispatcher +
+                CoroutineExceptionHandler { _, ex ->
+                    Minecraft.getInstance().gui.chat.addMessage(
+                        Component.translatable("sheeplib.error.coroutine").withStyle { it.withColor(ChatFormatting.RED) }
+                    )
+                    LoggerFactory.getLogger("SheepLib").error("Exception caught in dialog coroutine scope (${this::class.jvmName}):\n" + ex.stackTraceToString())
+                    close()
+                }
+    }
 
     /** Cancels the coroutine context. Must be invoked by overriders. */
     @MustBeInvokedByOverriders
@@ -30,4 +46,4 @@ public abstract class CoroutineScopeDialog(
 }
 
 /** A cancellation exception that indicates that a job's [CoroutineScopeDialog] was closed. */
-public object DialogClosedCancellationException: CancellationException()
+public object DialogClosedCancellationException : CancellationException()

test-mod/src/main/kotlin/com/noxcrew/sheeplib/testmod/ExceptionCoroutineDialog.kt

@@ -0,0 +1,27 @@
+package com.noxcrew.sheeplib.testmod
+
+import com.noxcrew.sheeplib.coroutines.CoroutineScopeDialog
+import com.noxcrew.sheeplib.layout.grid
+import com.noxcrew.sheeplib.theme.DefaultTheme
+import com.noxcrew.sheeplib.theme.Themed
+import kotlinx.coroutines.delay
+import kotlinx.coroutines.launch
+import net.minecraft.client.Minecraft
+import net.minecraft.client.gui.components.StringWidget
+import net.minecraft.client.gui.layouts.Layout
+import net.minecraft.network.chat.Component
+import kotlin.time.Duration.Companion.seconds
+
+/**
+ * A coroutine scope dialog that throws an exception in a coroutine.
+ */
+public class ExceptionCoroutineDialog(x: Int, y: Int) : CoroutineScopeDialog(x, y), Themed by DefaultTheme {
+    override fun layout(): Layout = grid {
+        launch {
+            delay(1.seconds)
+            error("Test exception from the exception coroutine dialog. This is not a bug.")
+        }
+
+        StringWidget(Component.literal("This dialog will error shortly"), Minecraft.getInstance().font).atBottom(0)
+    }
+}

test-mod/src/main/kotlin/com/noxcrew/sheeplib/testmod/SheepLibTestMod.kt

@@ -34,6 +34,7 @@ public object SheepLibTestMod : ClientModInitializer {
         "progress" to ::ProgressDialog,
         "buttons" to ::ButtonCollectionsDialog,
         "exception" to ::ExceptionDialog,
+        "exception-coroutine" to ::ExceptionCoroutineDialog,
         "z-index" to ::AdjustableZIndexDialog
     )