Fixed purging of connections after rediscovery

After rediscovery newly obtained routing table is compared to the known
routing table to find all servers that are "stale" - in the current table
but not in the new one. Connections to such servers are supposed to
be terminated.

However this did not happen because purging function was not invoked
correctly. This commit fixes the issue.

Author: lutovich

src/v1/routing-driver.js

@@ -145,7 +145,7 @@ class RoutingDriver extends Driver {
 
     // close old connections to servers not present in the new routing table
     const staleServers = currentRoutingTable.serversDiff(newRoutingTable);
-    staleServers.forEach(server => this._pool.purge);
+    staleServers.forEach(server => this._pool.purge(server));
 
     // make this driver instance aware of the new table
     this._routingTable = newRoutingTable;

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

@@ -64,6 +64,37 @@ describe('routing driver', () => {
     });
   });
 
+  it('should purge connections to stale servers after routing table refresh', done => {
+    if (!boltkit.BoltKitSupport) {
+      done();
+      return;
+    }
+
+    const kit = new boltkit.BoltKit();
+    const router = kit.start('./test/resources/boltkit/acquire_endpoints.script', 9042);
+    const reader = kit.start('./test/resources/boltkit/read_server.script', 9005);
+
+    kit.run(() => {
+      const driver = newDriver('bolt+routing://127.0.0.1:9042');
+      const session = driver.session(neo4j.session.READ);
+      session.run('MATCH (n) RETURN n.name').then(() => {
+        session.close();
+
+        expect(driver._pool.has('127.0.0.1:9042')).toBeFalsy();
+        expect(driver._pool.has('127.0.0.1:9005')).toBeTruthy();
+
+        driver.close();
+        router.exit(routerCode => {
+          reader.exit(readerCode => {
+            expect(routerCode).toEqual(0);
+            expect(readerCode).toEqual(0);
+            done();
+          });
+        });
+      });
+    });
+  });
+
   it('should discover new servers', done => {
     if (!boltkit.BoltKitSupport) {
       done();