Delete improvements (#151)

Signed-off-by: Dwitry <dwitry@users.noreply.github.com>
opencypher · Aug 2, 2018 · b1f0c9a · b1f0c9a
1 parent 54557e2
commit b1f0c9a
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Showing 2 changed files with 33 additions and 8 deletions.
diff --git a/testware/integration-tests/src/test/java/org/opencypher/gremlin/queries/DeleteTest.java b/testware/integration-tests/src/test/java/org/opencypher/gremlin/queries/DeleteTest.java
@@ -198,4 +198,26 @@ public void deleteOnNullNode() throws Exception {
         assertThat(onDelete)
             .isEmpty();
     }
+
+    @Test
+    public void deleteConnectedNodeAndRelationship() {
+        List<Map<String, Object>> beforeDelete = submitAndGet(
+            "MATCH (n) RETURN count(*)"
+        );
+        List<Map<String, Object>> onDelete = submitAndGet(
+            "MATCH (s:software {name: 'ripple'})<-[r:created]-(p:person) DELETE s, r"
+        );
+        List<Map<String, Object>> afterDelete = submitAndGet(
+            "MATCH (n) RETURN count(*)"
+        );
+
+        assertThat(beforeDelete)
+            .extracting("count(*)")
+            .containsExactly(6L);
+        assertThat(onDelete)
+            .isEmpty();
+        assertThat(afterDelete)
+            .extracting("count(*)")
+            .containsExactly(5L);
+    }
 }
diff --git a/translation/src/main/scala/org/opencypher/gremlin/translation/walker/DeleteWalker.scala b/translation/src/main/scala/org/opencypher/gremlin/translation/walker/DeleteWalker.scala
@@ -33,11 +33,14 @@ class DeleteWalker[T, P](context: WalkerContext[T, P], g: GremlinSteps[T, P]) {
 
   def walkClause(node: Delete): Unit = {
     val Delete(expressions, detach) = node
+    val edgesFirst = expressions.sortBy(e =>
+      context.expressionTypes.get(e) match {
+        case Some(_: RelationshipType) => false
+        case _                         => true
+    })
 
-    val sideEffect = g.start()
-    expressions.foreach(safeDelete(sideEffect, _, detach))
-
-    g.barrier().sideEffect(sideEffect)
+    g.barrier()
+    edgesFirst.foreach(safeDelete(g, _, detach))
   }
 
   private def safeDelete(
@@ -48,18 +51,18 @@ class DeleteWalker[T, P](context: WalkerContext[T, P], g: GremlinSteps[T, P]) {
     val expressionTraversal = ExpressionWalker.walkLocal(context, g, expr)
     val typ = context.expressionTypes.get(expr)
 
+    expressionTraversal.is(p.neq(Tokens.NULL))
+
     if (!checkBeforeDelete) {
       typ match {
         case Some(_: NodeType) =>
           expressionTraversal.sideEffect(
             g.start()
-              .is(p.neq(Tokens.NULL))
               .bothE()
               .constant(DELETE_CONNECTED_NODE.toString)
               .map(CustomFunction.cypherException())
           )
-        case Some(_: RelationshipType) =>
-        case _                         =>
+        case _ =>
       }
     }
 
@@ -72,6 +75,6 @@ class DeleteWalker[T, P](context: WalkerContext[T, P], g: GremlinSteps[T, P]) {
       case _                =>
     }
 
-    subTraversal.sideEffect(expressionTraversal.is(p.neq(Tokens.NULL)).drop())
+    subTraversal.sideEffect(expressionTraversal.drop())
   }
 }