Release connections to correct pool when using routing driver

src/v1/driver.js

@@ -72,7 +72,7 @@ class Driver {
     let conn = connect(url, this._config);
     conn.initialize(this._userAgent, this._token, streamObserver);
     conn._id = sessionId;
-    conn._release = () => release(this._url, conn);
+    conn._release = () => release(url, conn);
 
     this._openSessions[sessionId] = conn;
     return conn;

test/resources/boltkit/single_write_server.script

@@ -0,0 +1,9 @@
+!: AUTO INIT
+!: AUTO RESET
+!: AUTO PULL_ALL
+
+C: RUN "CALL dbms.cluster.routing.getServers" {}
+   PULL_ALL
+S: SUCCESS {"fields": ["ttl", "servers"]}
+   RECORD [9223372036854775807, [{"addresses": ["127.0.0.1:9001"],"role": "WRITE"}, {"addresses": ["127.0.0.1:9005","127.0.0.1:9003"], "role": "READ"},{"addresses": ["127.0.0.1:9004","127.0.0.1:9002","127.0.0.1:9003"], "role": "ROUTE"}]]
+   SUCCESS {}

test/resources/boltkit/two_write_responses_server.script

@@ -0,0 +1,12 @@
+!: AUTO INIT
+!: AUTO RESET
+!: AUTO PULL_ALL
+
+C: RUN "CREATE (n {name:'Bob'})" {}
+   PULL_ALL
+S: SUCCESS {}
+   SUCCESS {}
+C: RUN "CREATE ()" {}
+   PULL_ALL
+S: SUCCESS {}
+   SUCCESS {}

test/v1/routing.driver.boltkit.it.js

@@ -640,5 +640,37 @@ describe('routing driver ', function () {
         });
       });
   });
-});
+  it('should re-use connections', function (done) {
+    if (!boltkit.BoltKitSupport) {
+      done();
+      return;
+    }
+    // Given
+    var kit = new boltkit.BoltKit();
+    var seedServer = kit.start('./test/resources/boltkit/single_write_server.script', 9002);
+    var writeServer = kit.start('./test/resources/boltkit/two_write_responses_server.script', 9001);
 
+    kit.run(function () {
+      var driver = neo4j.driver("bolt+routing://127.0.0.1:9002", neo4j.auth.basic("neo4j", "neo4j"));
+      // When
+      var session = driver.session(neo4j.session.WRITE);
+      session.run("CREATE (n {name:'Bob'})").then(function () {
+        session.close(function() {
+          var connections = Object.keys(driver._openSessions).length
+          session = driver.session(neo4j.session.WRITE);
+          session.run("CREATE ()").then(function () {
+            driver.close();
+            seedServer.exit(function (code1) {
+              writeServer.exit(function (code2) {
+                expect(connections).toEqual(Object.keys(driver._openSessions).length)
+                expect(code1).toEqual(0);
+                expect(code2).toEqual(0);
+                done();
+              });
+            });
+          });
+        });
+      });
+    });
+  });
+});