1 files changed, 42 insertions, 0 deletions
diff --git a/src/test/java/gregtech/common/items/CombTypeTest.java b/src/test/java/gregtech/common/items/CombTypeTest.java
new file mode 100644
index 0000000000..d9ae1a46ca
--- /dev/null
+++ b/src/test/java/gregtech/common/items/CombTypeTest.java
@@ -0,0 +1,42 @@
+package gregtech.common.items;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import java.util.HashSet;
+import java.util.Set;
+
+import org.junit.jupiter.api.Test;
+
+class CombTypeTest {
+
+    @Test
+    void noDuplicateID() {
+        Set<Integer> seen = new HashSet<>();
+        for (CombType value : CombType.values()) {
+            assertTrue(seen.add(value.getId()), "Comb type must not have duplicate ID");
+        }
+    }
+
+    @Test
+    void noNegativeID() {
+        for (CombType value : CombType.values()) {
+            if (value == CombType._NULL) assertTrue(value.getId() <= 0, "Comb type ID must be negative for _NULL");
+            else assertTrue(value.getId() >= 0, "Comb type ID must not be negative");
+        }
+    }
+
+    @Test
+    void invalidIDNotNull() {
+        assertEquals(CombType.valueOf(-2), CombType._NULL, "Invalid ID Lookup should result in _NULL");
+        assertEquals(CombType.valueOf(Integer.MAX_VALUE), CombType._NULL, "Invalid ID Lookup should result in _NULL");
+    }
+
+    @Test
+    void validIDCorrectComb() {
+        for (CombType value : CombType.values()) {
+            if (value != CombType._NULL)
+                assertEquals(CombType.valueOf(value.getId()), value, "Valid ID Lookup should result in correct output");
+        }
+    }
+}