From 7bae7bddabeeecbe02cd3c05976bd0628450c876 Mon Sep 17 00:00:00 2001
From: Dwitry <dwitry@users.noreply.github.com>
Date: Fri, 18 Jan 2019 17:22:04 +0200
Subject: [PATCH] Revert #218 as support was removed on Neptune

- Document specific

Signed-off-by: Dwitry dwitry@users.noreply.github.com
---
 .../gremlin/groups/SkipWithNeptune.java       | 11 ++++++++
 .../gremlin/queries/SpecificsTest.java        | 28 ++++++++++++++++++-
 .../ir/rewrite/NeptuneFlavor.scala            | 10 +++++++
 3 files changed, 48 insertions(+), 1 deletion(-)

diff --git a/testware/integration-tests/src/test/java/org/opencypher/gremlin/groups/SkipWithNeptune.java b/testware/integration-tests/src/test/java/org/opencypher/gremlin/groups/SkipWithNeptune.java
index 2822fe6e..a3126324 100644
--- a/testware/integration-tests/src/test/java/org/opencypher/gremlin/groups/SkipWithNeptune.java
+++ b/testware/integration-tests/src/test/java/org/opencypher/gremlin/groups/SkipWithNeptune.java
@@ -34,6 +34,17 @@ public interface SkipWithNeptune {
     interface Limit0 extends SkipWithNeptune {
     }
 
+    /**
+     * Unable to start traversal with `.inject` step.
+     * error message : no viable alternative at input 'g.inject'
+     *
+     * @see SpecificsTest#gInjectGremlin()
+     * @see SpecificsTest#gInject()
+     * @see NeptuneFlavor#injectWorkaround(Seq) Workaround
+     */
+    interface gInject extends SkipWithNeptune {
+    }
+
     /**
      * Count step traversal is not aliased.
      *
diff --git a/testware/integration-tests/src/test/java/org/opencypher/gremlin/queries/SpecificsTest.java b/testware/integration-tests/src/test/java/org/opencypher/gremlin/queries/SpecificsTest.java
index 27c6180c..e263e537 100644
--- a/testware/integration-tests/src/test/java/org/opencypher/gremlin/queries/SpecificsTest.java
+++ b/testware/integration-tests/src/test/java/org/opencypher/gremlin/queries/SpecificsTest.java
@@ -55,7 +55,7 @@ private List<Map<String, Object>> submitAndGet(String cypher) {
     public void return100Elements() throws Exception {
         Client client = gremlinServer.gremlinClient();
 
-        client.submit("g.inject(1).times(100).repeat(addV().property('the_property', 'the_value'))").all().get();
+        client.submit("g.V().limit(0).inject(1).times(100).repeat(addV().property('the_property', 'the_value'))").all().get();
 
         List<Result> results = client.submit("g.V()").all().get();
 
@@ -226,4 +226,30 @@ public void noExceptionDetailMessage() throws Exception {
         assertThatThrownBy(() -> client.submit("g.inject(1).math('_ / 0')").all().get())
             .hasMessageContaining("Division by zero");
     }
+
+    /**
+     * @see #gInject()
+     */
+    @Test
+    @Category(SkipWithNeptune.gInject.class)
+    public void gInjectGremlin() throws Exception {
+        Client client = gremlinServer.gremlinClient();
+
+        String test = client.submit("g.inject('test')").one().getString();
+
+        assertThat(test).isEqualTo("test");
+    }
+
+    /**
+     * @see NeptuneFlavor#injectWorkaround(Seq)
+     */
+    @Test
+    public void gInject() throws Exception {
+        List<Map<String, Object>> results = submitAndGet("RETURN 'test' as r");
+
+        assertThat(results)
+            .extracting("r")
+            .containsExactly("test");
+    }
+
 }
diff --git a/translation/src/main/scala/org/opencypher/gremlin/translation/ir/rewrite/NeptuneFlavor.scala b/translation/src/main/scala/org/opencypher/gremlin/translation/ir/rewrite/NeptuneFlavor.scala
index 3c1ae5fb..0d38d5b4 100644
--- a/translation/src/main/scala/org/opencypher/gremlin/translation/ir/rewrite/NeptuneFlavor.scala
+++ b/translation/src/main/scala/org/opencypher/gremlin/translation/ir/rewrite/NeptuneFlavor.scala
@@ -26,6 +26,7 @@ import org.opencypher.gremlin.translation.ir.model.{GremlinStep, _}
 object NeptuneFlavor extends GremlinRewriter {
   override def apply(steps: Seq[GremlinStep]): Seq[GremlinStep] = {
     Seq(
+      injectWorkaround(_),
       limit0Workaround(_),
       multipleLabelsWorkaround(_),
       aggregateWithSameNameWorkaround(_),
@@ -80,6 +81,15 @@ object NeptuneFlavor extends GremlinRewriter {
     })(bySteps)
   }
 
+  private def injectWorkaround(steps: Seq[GremlinStep]): Seq[GremlinStep] = {
+    steps match {
+      case Inject(s) :: rest =>
+        Vertex :: Limit(0) :: Inject(s) :: rest
+      case _ =>
+        steps
+    }
+  }
+
   private def limit0Workaround(steps: Seq[GremlinStep]): Seq[GremlinStep] = {
     replace({
       case Barrier :: Limit(0) :: rest =>