fixed merge of sql actions

Author: arcuri82

core/src/main/kotlin/org/evomaster/core/problem/enterprise/EnterpriseIndividual.kt

@@ -409,10 +409,24 @@ abstract class EnterpriseIndividual(
      * if [relativePosition] = -1, append the [actions] at the end
      */
     fun addInitializingDbActions(relativePosition: Int=-1, actions: List<Action>){
-        if (relativePosition < 0)  {
-            addChildrenToGroup(getLastIndexOfDbActionToAdd(), actions, GroupsOfChildren.INITIALIZATION_SQL)
-        } else{
-            addChildrenToGroup(getFirstIndexOfDbActionToAdd()+relativePosition, actions, GroupsOfChildren.INITIALIZATION_SQL)
+        /*
+            SQL actions representing existing data must ALWAYS be at the beginning.
+            Recall those are only used for FKs.
+         */
+        val (existing, others) = actions.partition { it is SqlAction && it.representExistingData }
+
+        if(existing.isNotEmpty()){
+            addChildrenToGroup(getFirstIndexOfDbActionToAdd(), existing, GroupsOfChildren.INITIALIZATION_SQL)
+            //TODO shall we check for duplications???
+        }
+
+        if(others.isNotEmpty()) {
+            val pos = if (relativePosition < 0) {
+                getLastIndexOfDbActionToAdd()
+            } else {
+                getFirstIndexOfDbActionToAdd() + relativePosition
+            }
+            addChildrenToGroup(pos, others, GroupsOfChildren.INITIALIZATION_SQL)
         }
     }
 

core/src/test/kotlin/org/evomaster/core/problem/rest/service/RestIndividualBuilderTest.kt

@@ -14,6 +14,8 @@ import org.evomaster.core.sql.schema.ColumnDataType
 import org.evomaster.core.sql.schema.Table
 import org.evomaster.core.sql.schema.TableId
 import org.junit.jupiter.api.Assertions.assertEquals
+import org.junit.jupiter.api.Assertions.assertFalse
+import org.junit.jupiter.api.Assertions.assertTrue
 import org.junit.jupiter.api.Test
 
 class RestIndividualBuilderTest {
@@ -168,9 +170,16 @@ class RestIndividualBuilderTest {
         // initializing SQL actions should contain both sql1 and sql2
         val inits = merged.seeInitializingActions().filterIsInstance<SqlAction>()
         assertEquals(4, inits.size)
-        // check their table names preserved and order: first's sql then second's sql
-        assertEquals("T1", inits[0].table.name)
-        assertEquals("T2", inits[1].table.name)
+        /*
+            check their table names preserved and order: first's sql then second's sql.
+            however, existing data is always at the beginning
+         */
+        assertTrue(inits[0].representExistingData)
+        assertTrue(inits[1].representExistingData)
+        assertFalse(inits[2].representExistingData)
+        assertFalse(inits[3].representExistingData)
+        assertEquals("T1", inits[2].table.name)
+        assertEquals("T2", inits[3].table.name)
 
         // merged total actions should be sum of both initial individuals
         val before = first.seeAllActions().size + second.seeAllActions().size