fix client.select() flow, was breaking tests intermittently

Author: Ben Buckman

test/test_sharding.js

@@ -253,58 +253,69 @@ describe('RedisShardingClient', function(){
 
   // the tests below rely on select(db) to differentiate the clients.
   // so make sure the selector is working.
+  //
+  // note, some of these tests rely on RedisClient's internal queuing for async flow.
+  //
   describe('test helpers', function(){
 
-    // @todo this seems to fail every so often!!! why?
     it('should select different dbs', function(done){
-      var client0 = redis.createClient(PORT, HOST);
-      client0.select(0);
+      var client0, client1, clients, shardClient, testKey, testVal0, testVal1;
 
-      var client1 = redis.createClient(PORT, HOST);
-      client1.select(1);
-
-      // should be equivalent to [client0, client1]
-      var clients = clientArray(2, true);
+      async.series([
+        function(next){
+          client0 = redis.createClient(PORT, HOST);
+          client0.select(0, next);
+        },
+        function(next){
+          client1 = redis.createClient(PORT, HOST);
+          client1.select(1, next);
+        },
+        function(next){
+          // should be equivalent to [client0, client1]
+          clients = clientArray(2, true);
 
-      var testKey = randomTestKey(),
-          testVal0 = randomTestKey(),
+          testKey = randomTestKey();
+          testVal0 = randomTestKey();
           testVal1 = randomTestKey();
 
-      client0.set(testKey, testVal0);
-      client1.set(testKey, testVal1);
-
-      client0.get(testKey, function(error, val){
-        assert.ifError(error);
-        assert.strictEqual(val, testVal0);
-      });
-      client1.get(testKey, function(error, val){
-        assert.ifError(error);
-        assert.strictEqual(val, testVal1);
-      });
-
-      clients[0].get(testKey, function(error, val){
-        assert.ifError(error);
-        assert.strictEqual(val, testVal0);
-      });
-      clients[1].get(testKey, function(error, val){
-        assert.ifError(error);
-        assert.strictEqual(val, testVal1);
-      });
+          client0.set(testKey, testVal0);
+          client1.set(testKey, testVal1);
 
-      var shardClient = new redis.RedisShardingClient({
-        clients: clients,
-        hashFunction: function(){}
-      });
-      shardClient.clients[0].get(testKey, function(error, val){
-        assert.ifError(error);
-        assert.strictEqual(val, testVal0);
-      });
-      shardClient.clients[1].get(testKey, function(error, val){
-        assert.ifError(error);
-        assert.strictEqual(val, testVal1);
+          client0.get(testKey, function(error, val){
+            assert.ifError(error);
+            assert.strictEqual(val, testVal0);
+          });
+          client1.get(testKey, function(error, val){
+            assert.ifError(error);
+            assert.strictEqual(val, testVal1);
+          });
 
-        done();
-      });
+          clients[0].get(testKey, function(error, val){
+            assert.ifError(error);
+            assert.strictEqual(val, testVal0);
+          });
+          clients[1].get(testKey, function(error, val){
+            assert.ifError(error);
+            assert.strictEqual(val, testVal1);
+            next();
+          });
+        },
+        function(next){
+          shardClient = new redis.RedisShardingClient({
+            clients: clients,
+            hashFunction: function(){}
+          });
+          shardClient.clients[0].get(testKey, function(error, val){
+            assert.ifError(error);
+            assert.strictEqual(val, testVal0);
+          });
+          shardClient.clients[1].get(testKey, function(error, val){
+            assert.ifError(error);
+            assert.strictEqual(val, testVal1);
+            next();
+          });
+        }
+      ], done);
     });
   });