JetBrains#25 Nullable sequence

sedovalx · May 19, 2017 · e8ab689 · e8ab689
1 parent 7bcf9b7
commit e8ab689
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Showing 2 changed files with 45 additions and 10 deletions.
diff --git a/src/main/kotlin/kotlinx.dnq/query/XdQuery.kt b/src/main/kotlin/kotlinx.dnq/query/XdQuery.kt
@@ -16,29 +16,43 @@ import kotlin.reflect.jvm.javaType
 
 interface XdQuery<out T : XdEntity> {
     val entityType: XdEntityType<T>
-    val entityIterable: Iterable<Entity>
+    val entityIterable: Iterable<Entity?>
 }
 
 class XdQueryImpl<out T : XdEntity>(
-        override val entityIterable: Iterable<Entity>,
+        override val entityIterable: Iterable<Entity?>,
         override val entityType: XdEntityType<T>) : XdQuery<T>
 
 private val <T : XdEntity> XdQuery<T>.queryEngine: QueryEngine
     get() = entityType.entityStore.queryEngine
 
-fun <T : XdEntity> Iterable<Entity>?.asQuery(entityType: XdEntityType<T>): XdQuery<T> {
+fun <T : XdEntity> Iterable<Entity?>?.asQuery(entityType: XdEntityType<T>): XdQuery<T> {
     return if (this != null) {
         XdQueryImpl(this, entityType)
     } else {
-        XdQueryImpl(EntityIterableBase.EMPTY, entityType)
+        XdQueryImpl(emptyList(), entityType)
     }
 }
 
-fun <T : XdEntity> XdQuery<T>.asSequence(): Sequence<T> {
-    return entityIterable.asSequence().map { entityType.wrap(it) }
+fun <T : XdEntity, TN : T?> XdQuery<T>.asGenericSequence(): Sequence<TN> {
+    return entityIterable.asSequence().map {
+        if (it == null) {
+            if (null is TN) {
+                null as TN
+            } else {
+                throw Exception()
+            }
+        } else {
+            entityType.wrap(it) as TN
+        }
+    }
 }
 
-operator fun <T : XdEntity> XdQuery<T>.iterator() = asSequence().iterator()
+fun <T : XdEntity> XdQuery<T>.asNullSequence(): Sequence<T?> = this.asGenericSequence<T, T?>()
+
+fun <T : XdEntity> XdQuery<T>.asSequence(): Sequence<T> = this.asGenericSequence()
+
+operator fun <T : XdEntity> XdQuery<T>.iterator(): Iterator<T> = this.asSequence().iterator()
 
 fun <T : XdEntity, C : MutableCollection<in T>> XdQuery<T>.toCollection(destination: C) = asSequence().toCollection(destination)
 

diff --git a/src/test/kotlin/kotlinx.dnq/PropertiesTest.kt b/src/test/kotlin/kotlinx.dnq/PropertiesTest.kt
@@ -5,9 +5,7 @@ import jetbrains.exodus.database.exceptions.NullPropertyException
 import jetbrains.exodus.database.exceptions.SimplePropertyValidationException
 import jetbrains.exodus.database.exceptions.UniqueIndexViolationException
 import jetbrains.exodus.entitystore.Entity
-import kotlinx.dnq.query.eq
-import kotlinx.dnq.query.first
-import kotlinx.dnq.query.query
+import kotlinx.dnq.query.*
 import kotlinx.dnq.simple.regex
 import kotlinx.dnq.simple.requireIf
 import kotlinx.dnq.util.getOldValue
@@ -301,4 +299,27 @@ class PropertiesTest : DBTest() {
         }
     }
 
+    @Test
+    fun `query of nullable property should not throw on materialization`() {
+        val boss = store.transactional {
+            User.new {
+                login = "boss"
+                skill = 1
+            }
+        }
+        store.transactional {
+            User.new {
+                login = "slave"
+                supervisor = boss
+                skill = 1
+            }
+        }
+        store.transactional {
+            User.all().mapDistinct(User::supervisor).asNullSequence().forEach {
+                println(it?.login ?: "null")
+            }
+        }
+
+    }
+
 }