Add explain to Cypher Clients Fixes #5.

testware/integration-tests/src/test/java/org/opencypher/gremlin/queries/ExplainTest.java

@@ -21,8 +21,6 @@
 import java.util.Map;
 import org.junit.ClassRule;
 import org.junit.Test;
-import org.junit.experimental.categories.Category;
-import org.opencypher.gremlin.groups.SkipWithGremlinGroovy;
 import org.opencypher.gremlin.rules.GremlinServerExternalResource;
 
 public class ExplainTest {
@@ -34,11 +32,7 @@ private List<Map<String, Object>> submitAndGet(String cypher) {
         return gremlinServer.cypherGremlinClient().submit(cypher).all();
     }
 
-    /**
-     * Explain only works with `cypher-gremlin-server-plugin`
-     */
     @Test
-    @Category(SkipWithGremlinGroovy.class)
     public void explainIntegration() throws Exception {
         String cypher = "EXPLAIN\n" +
             "MATCH (s)-[:MEMBER_OF]->(ss)\n" +

tinkerpop/cypher-gremlin-server-client/src/main/java/org/opencypher/gremlin/client/BytecodeCypherGremlinClient.java

@@ -15,6 +15,10 @@
  */
 package org.opencypher.gremlin.client;
 
+import static java.util.concurrent.CompletableFuture.completedFuture;
+import static org.opencypher.gremlin.client.ExplainTranslation.getExplanation;
+import static org.opencypher.gremlin.translation.StatementOption.EXPLAIN;
+
 import java.util.Map;
 import java.util.concurrent.CompletableFuture;
 import org.apache.tinkerpop.gremlin.driver.Client;
@@ -44,6 +48,11 @@ public void close() {
     @Override
     public CompletableFuture<CypherResultSet> submitAsync(String cypher, Map<String, ?> parameters) {
         CypherAstWrapper ast = CypherAstWrapper.parse(cypher, parameters);
+
+        if (ast.getOptions().contains(EXPLAIN)) {
+            return completedFuture(getExplanation(ast));
+        }
+
         Translator<GraphTraversal, P> translator = Translator.builder().traversal().build(flavor);
         Bytecode bytecode = ast.buildTranslation(translator).asAdmin().getBytecode();
         CompletableFuture<ResultSet> resultSetFuture = client.submitAsync(bytecode);

tinkerpop/cypher-gremlin-server-client/src/main/java/org/opencypher/gremlin/client/ExplainTranslation.java

@@ -0,0 +1,39 @@
+/*
+ * Copyright (c) 2018 "Neo4j, Inc." [https://neo4j.com]
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.opencypher.gremlin.client;
+
+import java.util.Collections;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+import org.apache.tinkerpop.gremlin.driver.Result;
+import org.opencypher.gremlin.translation.CypherAstWrapper;
+import org.opencypher.gremlin.translation.groovy.GroovyPredicate;
+import org.opencypher.gremlin.translation.translator.Translator;
+
+class ExplainTranslation {
+    static CypherResultSet getExplanation(CypherAstWrapper ast) {
+        Map<String, Object> explanation = new LinkedHashMap<>();
+        Translator<String, GroovyPredicate> translator = Translator.builder()
+            .gremlinGroovy()
+            .inlineParameters()
+            .build();
+        explanation.put("translation", ast.buildTranslation(translator));
+        explanation.put("options", ast.getOptions().toString());
+        List<Result> results = Collections.singletonList(new Result(explanation));
+        return new CypherResultSet(results.iterator());
+    }
+}

tinkerpop/cypher-gremlin-server-client/src/main/java/org/opencypher/gremlin/client/GroovyCypherGremlinClient.java

@@ -15,6 +15,10 @@
  */
 package org.opencypher.gremlin.client;
 
+import static java.util.concurrent.CompletableFuture.completedFuture;
+import static org.opencypher.gremlin.client.ExplainTranslation.getExplanation;
+import static org.opencypher.gremlin.translation.StatementOption.EXPLAIN;
+
 import java.util.Map;
 import java.util.concurrent.CompletableFuture;
 import org.apache.tinkerpop.gremlin.driver.Client;
@@ -42,6 +46,11 @@ public void close() {
     @Override
     public CompletableFuture<CypherResultSet> submitAsync(String cypher, Map<String, ?> parameters) {
         CypherAstWrapper ast = CypherAstWrapper.parse(cypher, parameters);
+
+        if (ast.getOptions().contains(EXPLAIN)) {
+            return completedFuture(getExplanation(ast));
+        }
+
         Translator<String, GroovyPredicate> translator = Translator.builder().gremlinGroovy().build(flavor);
         String gremlin = ast.buildTranslation(translator);
         Map<String, Object> extractedParameters = ast.getExtractedParameters();

tinkerpop/cypher-gremlin-server-client/src/main/java/org/opencypher/gremlin/client/InMemoryCypherGremlinClient.java

@@ -17,10 +17,9 @@
 
 import static java.util.concurrent.CompletableFuture.completedFuture;
 import static java.util.stream.Collectors.toList;
+import static org.opencypher.gremlin.client.ExplainTranslation.getExplanation;
 import static org.opencypher.gremlin.translation.StatementOption.EXPLAIN;
 
-import java.util.Collections;
-import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.concurrent.CompletableFuture;
@@ -29,7 +28,6 @@
 import org.apache.tinkerpop.gremlin.process.traversal.dsl.graph.GraphTraversal;
 import org.apache.tinkerpop.gremlin.process.traversal.dsl.graph.GraphTraversalSource;
 import org.opencypher.gremlin.translation.CypherAstWrapper;
-import org.opencypher.gremlin.translation.groovy.GroovyPredicate;
 import org.opencypher.gremlin.translation.translator.Translator;
 import org.opencypher.gremlin.traversal.ReturnNormalizer;
 
@@ -51,15 +49,7 @@ public CompletableFuture<CypherResultSet> submitAsync(String cypher, Map<String,
         CypherAstWrapper ast = CypherAstWrapper.parse(cypher, parameters);
 
         if (ast.getOptions().contains(EXPLAIN)) {
-            Map<String, Object> explanation = new LinkedHashMap<>();
-            Translator<String, GroovyPredicate> translator = Translator.builder()
-                .gremlinGroovy()
-                .inlineParameters()
-                .build();
-            explanation.put("translation", ast.buildTranslation(translator));
-            explanation.put("options", ast.getOptions().toString());
-            List<Result> results = Collections.singletonList(new Result(explanation));
-            return completedFuture(new CypherResultSet(results.iterator()));
+            return completedFuture(getExplanation(ast));
         }
 
         DefaultGraphTraversal g = new DefaultGraphTraversal(gts.clone());