EXPOSED-689 warmUpLinkedReferences() should not return all the values…

… from cache (#2355)

* EXPOSED-689 warmUpLinkedReferences() should not return all the values from cache

exposed-dao/src/main/kotlin/org/jetbrains/exposed/dao/EntityClass.kt

@@ -975,7 +975,10 @@ abstract class EntityClass<ID : Any, out T : Entity<ID>>(
         val distinctRefIds = references.distinct()
         val transaction = TransactionManager.current()
 
-        val inCache = transaction.entityCache.referrers[sourceRefColumn] ?: emptyMap()
+        val inCache = transaction.entityCache.referrers[sourceRefColumn]
+            ?.filterKeys { distinctRefIds.contains(it) }
+            ?: emptyMap()
+
         val loaded = ((distinctRefIds - inCache.keys).takeIf { it.isNotEmpty() } as List<EntityID<SID>>?)?.let { idsToLoad ->
             val alreadyInJoin = (dependsOnTables as? Join)?.alreadyInJoin(linkTable) ?: false
             val entityTables = if (alreadyInJoin) dependsOnTables else dependsOnTables.join(linkTable, JoinType.INNER, targetRefColumn, table.id)

exposed-tests/src/test/kotlin/org/jetbrains/exposed/sql/tests/shared/entities/WarmUpLinkedReferencesTests.kt

@@ -0,0 +1,61 @@
+package org.jetbrains.exposed.sql.tests.shared.entities
+
+import org.jetbrains.exposed.dao.IntEntity
+import org.jetbrains.exposed.dao.IntEntityClass
+import org.jetbrains.exposed.dao.id.EntityID
+import org.jetbrains.exposed.dao.id.IntIdTable
+import org.jetbrains.exposed.sql.tests.DatabaseTestsBase
+import org.jetbrains.exposed.sql.tests.shared.assertEquals
+import org.junit.Test
+
+class WarmUpLinkedReferencesTests : DatabaseTestsBase() {
+
+    object Box : IntIdTable() {
+        val value = integer("value")
+    }
+
+    class EBox(id: EntityID<Int>) : IntEntity(id) {
+        var value by Box.value
+
+        companion object : IntEntityClass<EBox>(Box)
+    }
+
+    object BoxItem : IntIdTable() {
+        val box = reference("box", Box)
+
+        val value = integer("value")
+    }
+
+    class EBoxItem(id: EntityID<Int>) : IntEntity(id) {
+        var value by BoxItem.value
+        var box by EBox referencedOn BoxItem.box
+
+        companion object : IntEntityClass<EBoxItem>(BoxItem)
+    }
+
+    @Test
+    fun warmUpLinkedReferencesShouldNotReturnAllTheValueFromCache() {
+        withTables(Box, BoxItem) {
+            val boxEntities = (0..4).map {
+                EBox.new {
+                    value = it
+                }
+            }
+
+            boxEntities.forEach {
+                EBoxItem.new {
+                    box = it
+                    value = it.id.value
+                }
+            }
+
+            val ids = boxEntities.map { it.id }
+
+            // Warm up all the entities to fill the cache
+            EBox.warmUpLinkedReferences(ids, BoxItem)
+
+            val warmedUp = EBox.warmUpLinkedReferences(ids.slice(0..2), BoxItem)
+            assertEquals(3, warmedUp.size)
+        }
+    }
+}