Gate JEI mixin behind mod presence check to prevent crashes without JEI

src/main/java/com/soliddowant/gregtechenergistics/mixins/GregTechEnergisticsMixinPlugin.java

@@ -0,0 +1,71 @@
+package com.soliddowant.gregtechenergistics.mixins;
+
+import java.util.List;
+import java.util.Set;
+
+import org.spongepowered.asm.lib.tree.ClassNode;
+import org.spongepowered.asm.mixin.extensibility.IMixinConfigPlugin;
+import org.spongepowered.asm.mixin.extensibility.IMixinInfo;
+
+import net.minecraftforge.fml.common.Loader;
+
+/**
+ * Mixin config plugin that conditionally loads mixins based on mod presence.
+ * This prevents crashes when optional dependencies like JEI are not installed.
+ * 
+ * <p>This plugin assumes that JEI-specific mixins are placed in a ".jei" subpackage
+ * under the main mixin package. For example, if the mixin package is
+ * "com.soliddowant.gregtechenergistics.mixins", then JEI mixins should be in
+ * "com.soliddowant.gregtechenergistics.mixins.jei".</p>
+ */
+public class GregTechEnergisticsMixinPlugin implements IMixinConfigPlugin {
+
+    private static final String JEI_PACKAGE_SUFFIX = ".jei.";
+    private static final String JEI_MOD_ID = "jei";
+
+    private String mixinPackage;
+
+    @Override
+    public void onLoad(String mixinPackage) {
+        this.mixinPackage = mixinPackage;
+    }
+
+    @Override
+    public String getRefMapperConfig() {
+        return null;
+    }
+
+    @Override
+    public boolean shouldApplyMixin(String targetClassName, String mixinClassName) {
+        // Only gate JEI-related mixins behind JEI presence check
+        // Check if the mixin is in the jei subpackage
+        String jeiMixinPackage = mixinPackage + JEI_PACKAGE_SUFFIX;
+        if (mixinClassName.startsWith(jeiMixinPackage)) {
+            return Loader.isModLoaded(JEI_MOD_ID);
+        }
+
+        // Apply all other mixins unconditionally
+        return true;
+    }
+
+    @Override
+    public void acceptTargets(Set<String> myTargets, Set<String> otherTargets) {
+        // No special target handling needed
+    }
+
+    @Override
+    public List<String> getMixins() {
+        // Return null to let the config file handle mixin listing
+        return null;
+    }
+
+    @Override
+    public void preApply(String targetClassName, ClassNode targetClass, String mixinClassName, IMixinInfo mixinInfo) {
+        // No pre-apply processing needed
+    }
+
+    @Override
+    public void postApply(String targetClassName, ClassNode targetClass, String mixinClassName, IMixinInfo mixinInfo) {
+        // No post-apply processing needed
+    }
+}

src/main/resources/mixins.gregtechenergistics.json

@@ -4,6 +4,7 @@
   "target": "@env(DEFAULT)",
   "minVersion": "0.8",
   "compatibilityLevel": "JAVA_8",
+  "plugin": "com.soliddowant.gregtechenergistics.mixins.GregTechEnergisticsMixinPlugin",
   "mixins": [
     "MetaTileEntityHolderMixin"
   ],