Fix KSP enum codegen with Convert annotation (#1411)

Author: jbl428

querydsl-examples/querydsl-example-ksp-codegen/src/main/kotlin/com/querydsl/example/ksp/Bear.kt

@@ -1,6 +1,7 @@
 package com.querydsl.example.ksp
 
 import com.querydsl.core.annotations.QueryProjection
+import jakarta.persistence.Convert
 import jakarta.persistence.Entity
 import jakarta.persistence.Id
 
@@ -9,7 +10,9 @@ class Bear(
 	@Id
 	val id: Int,
 	val name: String,
-	val location: String
+	val location: String,
+	@Convert(converter = BearSpeciesConverter::class)
+	val species: BearSpecies?
 )
 
 class BearSimplifiedProjection @QueryProjection constructor(

querydsl-examples/querydsl-example-ksp-codegen/src/main/kotlin/com/querydsl/example/ksp/BearSpecies.kt

@@ -0,0 +1,9 @@
+package com.querydsl.example.ksp
+
+enum class BearSpecies {
+    BROWN_BEAR,
+    BLACK_BEAR,
+    POLAR_BEAR,
+    PANDA,
+    SUN_BEAR,
+}

querydsl-examples/querydsl-example-ksp-codegen/src/main/kotlin/com/querydsl/example/ksp/BearSpeciesConverter.kt

@@ -0,0 +1,22 @@
+package com.querydsl.example.ksp
+
+import jakarta.persistence.AttributeConverter
+import jakarta.persistence.Converter
+
+@Converter
+class BearSpeciesConverter : AttributeConverter<BearSpecies, String> {
+    
+    override fun convertToDatabaseColumn(attribute: BearSpecies?): String? {
+        return attribute?.name?.lowercase()
+    }
+    
+    override fun convertToEntityAttribute(dbData: String?): BearSpecies? {
+        return dbData?.let { 
+            try {
+                BearSpecies.valueOf(it.uppercase())
+            } catch (e: IllegalArgumentException) {
+                null
+            }
+        }
+    }
+}

querydsl-examples/querydsl-example-ksp-codegen/src/test/kotlin/Tests.kt

@@ -1,4 +1,5 @@
 import com.querydsl.example.ksp.Bear
+import com.querydsl.example.ksp.BearSpecies
 import com.querydsl.example.ksp.Cat
 import com.querydsl.example.ksp.CatType
 import com.querydsl.example.ksp.Dog
@@ -181,7 +182,7 @@ class Tests {
         run {
             val em = emf.createEntityManager()
             em.transaction.begin()
-            em.persist(Bear(424, "Winnie", "The forest"))
+            em.persist(Bear(424, "Winnie", "The forest", null))
             em.transaction.commit()
             em.close()
         }
@@ -207,10 +208,40 @@ class Tests {
 
     @Test
     fun `query projection exclude property from constructor`() {
-        assertThat(Bear::class.declaredMemberProperties.count()).isEqualTo(3)
+        assertThat(Bear::class.declaredMemberProperties.count()).isEqualTo(4)
         assertThat(QBearSimplifiedProjection::class.primaryConstructor!!.parameters.count()).isEqualTo(2)
     }
 
+    @Test
+    fun `enum with convert annotation generates EnumPath`() {
+        val emf = initialize()
+
+        run {
+            val em = emf.createEntityManager()
+            em.transaction.begin()
+            em.persist(Bear(501, "Baloo", "Jungle", null))
+            em.transaction.commit()
+            em.close()
+        }
+
+        run {
+            val em = emf.createEntityManager()
+            val queryFactory = JPAQueryFactory(em)
+            val q = QBear.bear
+
+            val bears = queryFactory
+                .select(q.species.coalesce(BearSpecies.BLACK_BEAR))
+                .from(q)
+                .orderBy(q.id.asc())
+                .fetch()
+
+            assertThat(bears.size).isEqualTo(1)
+            assertThat(bears[0]).isEqualTo(BearSpecies.BLACK_BEAR)
+
+            em.close()
+        }
+    }
+
     @Test
     fun `create and query dog with jsonb tag`() {
         val emf = initialize()

querydsl-tooling/querydsl-ksp-codegen/src/main/kotlin/com/querydsl/ksp/codegen/TypeExtractor.kt

@@ -145,6 +145,10 @@ class TypeExtractor(
     }
 
     private fun userType(type: KSType): QPropertyType.Unknown? {
+        if (type.isEnum()) {
+            return null
+        }
+
         val userTypeAnnotations = listOf(
             ClassName("org.hibernate.annotations", "Type"),
             ClassName("org.hibernate.annotations", "JdbcTypeCode"),
@@ -204,3 +208,9 @@ private fun KSType.toClassNameSimple(): ClassName {
         else -> error("Could not compute ClassName for '$this'")
     }
 }
+
+private fun KSType.isEnum(): Boolean {
+    val referencedDeclaration = declaration
+
+    return referencedDeclaration is KSClassDeclaration && referencedDeclaration.classKind == ClassKind.ENUM_CLASS
+}