Improve the error messages for identifiers

Author: ErrorCraft

src/main/java/net/errorcraft/codecium/access/minecraft/util/InvalidIdentifierExceptionAccess.java

@@ -0,0 +1,6 @@
+package net.errorcraft.codecium.access.minecraft.util;
+
+public interface InvalidIdentifierExceptionAccess {
+    String codecium$messageWithoutId();
+    void codecium$setGivenIdentifier(String givenIdentifier);
+}

src/main/java/net/errorcraft/codecium/mixin/minecraft/util/IdentifierExtender.java

@@ -0,0 +1,81 @@
+package net.errorcraft.codecium.mixin.minecraft.util;
+
+import com.llamalad7.mixinextras.sugar.Local;
+import net.errorcraft.codecium.access.minecraft.util.InvalidIdentifierExceptionAccess;
+import net.minecraft.util.Identifier;
+import net.minecraft.util.InvalidIdentifierException;
+import org.spongepowered.asm.mixin.Final;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Shadow;
+import org.spongepowered.asm.mixin.Unique;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.ModifyArg;
+import org.spongepowered.asm.mixin.injection.Redirect;
+
+import java.util.function.Supplier;
+
+@Mixin(Identifier.class)
+public abstract class IdentifierExtender {
+    @Shadow
+    @Final
+    public static char NAMESPACE_SEPARATOR;
+
+    @Shadow
+    private static boolean isNamespaceCharacterValid(char character) {
+        return false;
+    }
+
+    @Shadow
+    public static boolean isPathCharacterValid(char character) {
+        return false;
+    }
+
+    @ModifyArg(
+        method = "validate",
+        at = @At(
+            value = "INVOKE",
+            target = "Lcom/mojang/serialization/DataResult;error(Ljava/util/function/Supplier;)Lcom/mojang/serialization/DataResult;",
+            remap = false
+        )
+    )
+    private static Supplier<String> identifierExceptionUseBetterMessage(Supplier<String> message, @Local(argsOnly = true) String id, @Local InvalidIdentifierException exception) {
+        return () -> ((InvalidIdentifierExceptionAccess) exception).codecium$messageWithoutId() + ": " + id;
+    }
+
+    @Redirect(
+        method = "validateNamespace",
+        at = @At(
+            value = "INVOKE",
+            target = "Lnet/minecraft/util/Identifier;isNamespaceValid(Ljava/lang/String;)Z"
+        )
+    )
+    @Unique
+    private static boolean validateNamespaceUseBetterMessage(String namespace, String path) {
+        for (int i = 0; i < namespace.length(); ++i) {
+            if (!isNamespaceCharacterValid(namespace.charAt(i))) {
+                InvalidIdentifierException exception = new InvalidIdentifierException("Invalid character '" + namespace.charAt(i) + "' in namespace of resource location");
+                ((InvalidIdentifierExceptionAccess) exception).codecium$setGivenIdentifier(namespace + NAMESPACE_SEPARATOR + path);
+                throw exception;
+            }
+        }
+        return true;
+    }
+
+    @Redirect(
+        method = "validatePath",
+        at = @At(
+            value = "INVOKE",
+            target = "Lnet/minecraft/util/Identifier;isPathValid(Ljava/lang/String;)Z"
+        )
+    )
+    private static boolean validatePathUseBetterMessage(String path, String namespace) {
+        for (int i = 0; i < path.length(); ++i) {
+            if (!isPathCharacterValid(path.charAt(i))) {
+                InvalidIdentifierException exception = new InvalidIdentifierException("Invalid character '" + path.charAt(i) + "' in path of resource location");
+                ((InvalidIdentifierExceptionAccess) exception).codecium$setGivenIdentifier(namespace + NAMESPACE_SEPARATOR + path);
+                throw exception;
+            }
+        }
+        return true;
+    }
+}

src/main/java/net/errorcraft/codecium/mixin/minecraft/util/InvalidIdentifierExceptionExtender.java

@@ -0,0 +1,30 @@
+package net.errorcraft.codecium.mixin.minecraft.util;
+
+import net.errorcraft.codecium.access.minecraft.util.InvalidIdentifierExceptionAccess;
+import net.minecraft.util.InvalidIdentifierException;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Unique;
+
+@Mixin(InvalidIdentifierException.class)
+public class InvalidIdentifierExceptionExtender extends RuntimeException implements InvalidIdentifierExceptionAccess {
+    @Unique
+    private String givenIdentifier;
+
+    @Override
+    public String getMessage() {
+        if (this.givenIdentifier == null) {
+            return super.getMessage();
+        }
+        return super.getMessage() + ": " + this.givenIdentifier;
+    }
+
+    @Override
+    public String codecium$messageWithoutId() {
+        return super.getMessage();
+    }
+
+    @Override
+    public void codecium$setGivenIdentifier(String givenIdentifier) {
+        this.givenIdentifier = givenIdentifier;
+    }
+}

src/main/resources/codecium.mixins.json

@@ -12,6 +12,8 @@
     "minecraft.registry.entry.RegistryElementCodecExtender",
     "minecraft.registry.entry.RegistryEntryListCodecExtender",
     "minecraft.registry.entry.RegistryFixedCodecExtender",
+    "minecraft.util.IdentifierExtender",
+    "minecraft.util.InvalidIdentifierExceptionExtender",
     "minecraft.util.dynamic.CodecsExtender",
     "mojang.serialization.CodecExtender",
     "mojang.serialization.DataResultExtender",