test: add test for InversePayload with FixedInt annotation and update TestClasses

Author: rasros

src/test/kotlin/com/eignex/kencode/PackedFormatTest.kt

@@ -301,4 +301,25 @@ class PackedFormatTest {
         )
         assertEquals(payload, decoded)
     }
+
+    @Test
+    fun `builder defaultVarInt is overridden by FixedInt annotation`() {
+        val payload = InversePayload(5, -10L, 6u, 7uL)
+
+        val optimizedFormat = PackedFormat {
+            defaultVarInt = true
+            defaultZigZag = true
+        }
+
+        val bytes = optimizedFormat.encodeToByteArray(
+            InversePayload.serializer(),
+            payload
+        )
+        assertEquals(24, bytes.size)
+        val decoded = optimizedFormat.decodeFromByteArray(
+            InversePayload.serializer(),
+            bytes
+        )
+        assertEquals(payload, decoded)
+    }
 }

src/test/kotlin/com/eignex/kencode/TestClasses.kt

@@ -630,3 +630,11 @@ data class PolymorphicContainer(
 
 @Serializable
 data class UnannotatedPayload(val x: Int, val y: Long)
+
+@Serializable
+data class InversePayload(
+    @FixedInt val fixedX: Int,
+    @FixedInt val fixedY: Long,
+    @FixedInt val fixedUX: UInt,
+    @FixedInt val fixedUY: ULong
+)