ColumnWithTransform to support nullable columns

JetBrains · Feb 11, 2023 · b225c41 · b225c41
1 parent fccdb92
commit b225c41
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Showing 2 changed files with 47 additions and 5 deletions.
diff --git a/exposed-dao/src/main/kotlin/org/jetbrains/exposed/dao/Entity.kt b/exposed-dao/src/main/kotlin/org/jetbrains/exposed/dao/Entity.kt
@@ -8,7 +8,7 @@ import org.jetbrains.exposed.sql.transactions.TransactionManager
 import kotlin.properties.Delegates
 import kotlin.reflect.KProperty
 
-open class ColumnWithTransform<TColumn, TReal>(
+open class ColumnWithTransform<TColumn: Any?, TReal: Any?>(
     val column: Column<TColumn>,
     val toColumn: (TReal) -> TColumn,
     toReal: (TColumn) -> TReal,
@@ -221,12 +221,16 @@ open class Entity<ID : Comparable<ID>>(val id: EntityID<ID>) {
         }
     }
 
-    operator fun <TColumn, TReal> ColumnWithTransform<TColumn, TReal>.getValue(o: Entity<ID>, desc: KProperty<*>): TReal =
-        toReal(column.getValue(o, desc))
+    operator fun <TColumn: Any?, TReal: Any?> ColumnWithTransform<TColumn, TReal>.getValue(o: Entity<ID>, desc: KProperty<*>): TReal? =
+        column.getValue(o, desc)?.let(toReal)
 
-    operator fun <TColumn, TReal> ColumnWithTransform<TColumn, TReal>.setValue(o: Entity<ID>, desc: KProperty<*>, value: TReal) {
+    operator fun <TColumn: Any?, TReal: Any?> ColumnWithTransform<TColumn, TReal>.setValue(o: Entity<ID>, desc: KProperty<*>, value: TReal) {
         column.setValue(o, desc, toColumn(value))
     }
+    @JvmName("setValueNullable")
+    operator fun <TColumn: Any?, TReal: Any> ColumnWithTransform<TColumn, TReal>.setValue(o: Entity<ID>, desc: KProperty<*>, value: TReal?) {
+        column.setValue(o, desc, value?.let(toColumn) as TColumn)
+    }
 
     infix fun <TID : Comparable<TID>, Target : Entity<TID>> EntityClass<TID, Target>.via(table: Table): InnerTableLink<ID, Entity<ID>, TID, Target> =
         InnerTableLink(table, this@Entity.id.table, this@via)

diff --git a/...rc/test/kotlin/org/jetbrains/exposed/sql/tests/shared/entities/ColumnWithTransformTest.kt b/...rc/test/kotlin/org/jetbrains/exposed/sql/tests/shared/entities/ColumnWithTransformTest.kt
@@ -12,7 +12,10 @@ import org.junit.Test
 
 object TransformTables {
     object Transformations : IntIdTable() {
-        val value = varchar("name", 50)
+        val value = varchar("value", 50)
+    }
+    object NullableTransformations: IntIdTable() {
+        val value = varchar("nullable", 50).nullable()
     }
     class Transformation(id: EntityID<Int>) : IntEntity(id) {
         companion object : IntEntityClass<Transformation>(Transformations)
@@ -21,6 +24,13 @@ object TransformTables {
             toReal = { it.replace("transformed-", "") }
         )
     }
+    class NullableTransformation(id: EntityID<Int>) : IntEntity(id) {
+        companion object : IntEntityClass<NullableTransformation>(NullableTransformations)
+        var value by NullableTransformations.value.transform(
+            toColumn = { "transformed-$it" },
+            toReal = { it?.replace("transformed-", "") }
+        )
+    }
 }
 
 class ColumnWithTransformTest: DatabaseTestsBase() {
@@ -39,4 +49,32 @@ class ColumnWithTransformTest: DatabaseTestsBase() {
             assertEquals("transformed-stuff", row[TransformTables.Transformations.value])
         }
     }
+
+    @Test fun `set and get nullable value - while present`() {
+        withTables(TransformTables.NullableTransformations) {
+            val entity = TransformTables.NullableTransformation.new {
+                value = "stuff"
+            }
+
+            assertEquals("stuff", entity.value)
+
+            val row = TransformTables.NullableTransformations.select(Op.TRUE)
+                .first()
+
+            assertEquals("transformed-stuff", row[TransformTables.NullableTransformations.value])
+        }
+    }
+
+    @Test fun `set and get nullable value - while absent`() {
+        withTables(TransformTables.NullableTransformations) {
+            val entity = TransformTables.NullableTransformation.new {}
+
+            assertEquals(null, entity.value)
+
+            val row = TransformTables.NullableTransformations.select(Op.TRUE)
+                .first()
+
+            assertEquals(null, row[TransformTables.NullableTransformations.value])
+        }
+    }
 }