check field size

smt-common/src/main/scala/org/bitlap/common/TransformerMacro.scala

@@ -114,8 +114,16 @@ class TransformerMacro(override val c: whitebox.Context) extends AbstractMacroPr
 
   private def getTransformBody[From: WeakTypeTag, To: WeakTypeTag]: Tree = {
     val toClassName   = resolveClassTypeName[To]
+    val fromClassName = resolveClassTypeName[From]
     val toClassInfo   = getCaseClassFieldInfo[To]()
     val fromClassInfo = getCaseClassFieldInfo[From]()
+    if (fromClassInfo.size < toClassInfo.size) {
+      c.abort(
+        c.enclosingPosition,
+        s"From type: `$fromClassName` has fewer fields than To type: `$toClassName` and cannot be transformed"
+      )
+    }
+
     val customFieldNameMapping =
       MacroCache.classFieldNameMapping.getOrElse(getBuilderId(annoBuilderPrefix), mutable.Map.empty)
     val customFieldValueMapping =

smt-common/src/test/scala/org/bitlap/common/TransformableTest.scala

@@ -156,8 +156,6 @@ class TransformableTest extends AnyFlatSpec with Matchers {
       |    val a1 = A1("hello", 1, 2, None)
       |    val a2 = Transformer[A1, A2].transform(a1)
       |    a2.toString shouldBe "A2(hello,1,2,None)"
-      |    
-      |    
       |""".stripMargin shouldNot compile
   }
 
@@ -182,4 +180,20 @@ class TransformableTest extends AnyFlatSpec with Matchers {
 
     actualToQueryResult shouldBe expectToQueryResult
   }
+
+  "TransformableTest From have fewer fields than To" should "compile error" in {
+    """
+      |    case class B1(a: List[String])
+      |    case class B2(a: List[String], b: Int)
+      |    val b2 = Transformable[B1, B2].instance.transform(B1(List.empty))
+      |    println(b2)
+      |""".stripMargin shouldNot compile
+  }
+
+  "TransformableTest From have more fields than To" should "ok" in {
+    case class B1(a: List[String], b: Int)
+    case class B2(a: List[String])
+    val b2 = Transformable[B1, B2].instance.transform(B1(List.empty, 1))
+    println(b2)
+  }
 }