Render cached remote suggestions immediately

src/dataset.js

@@ -248,14 +248,19 @@ var Dataset = (function() {
     getSuggestions: function(query, cb) {
       var that = this,
           terms = utils.tokenizeQuery(query),
-          suggestions = this._getLocalSuggestions(terms).slice(0, this.limit);
+          suggestions = this._getLocalSuggestions(terms).slice(0, this.limit),
+          cacheHit = false;
 
-      cb && cb(suggestions);
 
       if (suggestions.length < this.limit && this.transport) {
-        this.transport.get(query, processRemoteData);
+        cacheHit = this.transport.get(query, processRemoteData);
       }
 
+      // if a cache hit occurred, skip rendering local suggestions
+      // because the rendering of local/remote suggestions is already
+      // in the event loop
+      !cacheHit && cb && cb(suggestions);
+
       // callback for transport.get
       function processRemoteData(data) {
         suggestions = suggestions.slice(0);

src/transport.js

@@ -34,15 +34,41 @@ var Transport = (function() {
       beforeSend: o.beforeSend
     };
 
-    this.get = (/^throttle$/i.test(o.rateLimitFn) ?
-      utils.throttle : utils.debounce)(this.get, o.rateLimitWait || 300);
+    this._get = (/^throttle$/i.test(o.rateLimitFn) ?
+      utils.throttle : utils.debounce)(this._get, o.rateLimitWait || 300);
   }
 
   utils.mixin(Transport.prototype, {
 
     // private methods
     // ---------------
 
+    _get: function(url, cb) {
+      var that = this;
+
+      // under the pending request threshold, so fire off a request
+      if (belowPendingRequestsThreshold()) {
+        this._sendRequest(url).done(done);
+      }
+
+      // at the pending request threshold, so hang out in the on deck circle
+      else {
+        this.onDeckRequestArgs = [].slice.call(arguments, 0);
+      }
+
+      // success callback
+      function done(resp) {
+        var data = that.filter ? that.filter(resp) : resp;
+
+        cb && cb(data);
+
+        // cache the resp and not the results of applying filter
+        // in case multiple datasets use the same url and
+        // have different filters
+        requestCache.set(url, resp);
+      }
+    },
+
     _sendRequest: function(url) {
       var that = this, jqXhr = pendingRequests[url];
 
@@ -60,7 +86,7 @@ var Transport = (function() {
 
         // ensures request is always made for the last query
         if (that.onDeckRequestArgs) {
-          that.get.apply(that, that.onDeckRequestArgs);
+          that._get.apply(that, that.onDeckRequestArgs);
           that.onDeckRequestArgs = null;
         }
       }
@@ -75,36 +101,24 @@ var Transport = (function() {
           url,
           resp;
 
+      cb = cb || utils.noop;
+
       url = this.replace ?
         this.replace(this.url, encodedQuery) :
         this.url.replace(this.wildcard, encodedQuery);
 
       // in-memory cache hit
       if (resp = requestCache.get(url)) {
-        cb && cb(this.filter ? this.filter(resp) : resp);
-      }
-
-      // under the pending request threshold, so fire off a request
-      else if (belowPendingRequestsThreshold()) {
-        this._sendRequest(url).done(done);
+        // defer to stay consistent with behavior of ajax call
+        utils.defer(function() { cb(that.filter ? that.filter(resp) : resp); });
       }
 
-      // at the pending request threshold, so hang out in the on deck circle
       else {
-        this.onDeckRequestArgs = [].slice.call(arguments, 0);
+        this._get(url, cb);
       }
 
-      // success callback
-      function done(resp) {
-        var data = that.filter ? that.filter(resp) : resp;
-
-        cb && cb(data);
-
-        // cache the resp and not the result of applying filter
-        // in case multiple datasets use the same url and
-        // have different filters
-        requestCache.set(url, resp);
-      }
+      // return bool indicating whether or not a cache hit occurred
+      return !!resp;
     }
   });
 

test/dataset_spec.js

@@ -344,26 +344,30 @@ describe('Dataset', function() {
       var spy = jasmine.createSpy(),
           remote = [fixtureDatums[0], fixtureStrings[2]];
 
-      this.dataset.transport.get.andCallFake(function(q, cb) { cb(remote); });
+      this.dataset.transport.get.andCallFake(function(q, cb) {
+        utils.defer(function() { cb(remote); });
+      });
 
       this.dataset.getSuggestions('c', spy);
 
-      expect(spy.callCount).toBe(2);
-
-      // local suggestions
-      expect(spy.argsForCall[0][0]).toEqual([
-        expectedItemHash.coconut,
-        expectedItemHash.cake,
-        expectedItemHash.coffee
-      ]);
-
-      // local + remote suggestions
-      expect(spy.argsForCall[1][0]).toEqual([
-        expectedItemHash.coconut,
-        expectedItemHash.cake,
-        expectedItemHash.coffee,
-        expectedItemHash.grape
-      ]);
+      waitsFor(function() { return spy.callCount === 2; });
+
+      runs(function() {
+        // local suggestions
+        expect(spy.argsForCall[0][0]).toEqual([
+          expectedItemHash.coconut,
+          expectedItemHash.cake,
+          expectedItemHash.coffee
+        ]);
+
+        // local + remote suggestions
+        expect(spy.argsForCall[1][0]).toEqual([
+          expectedItemHash.coconut,
+          expectedItemHash.cake,
+          expectedItemHash.coffee,
+          expectedItemHash.grape
+        ]);
+      });
     });
   });
 

test/transport_spec.js

@@ -57,11 +57,17 @@ describe('Transport', function() {
       });
 
       it('should call filter', function() {
-        expect(this.transport.filter).toHaveBeenCalled();
+        waitsFor(function() {
+          return this.transport.filter.callCount === 1;
+        });
       });
 
       it('should invoke callback with data', function() {
-        expect(this.spy).toHaveBeenCalledWith(['val']);
+        waitsFor(function() { return this.spy.callCount === 1; });
+
+        runs(function() {
+          expect(this.spy).toHaveBeenCalledWith(['val']);
+        });
       });
     });
 
@@ -120,7 +126,8 @@ describe('Transport', function() {
       });
 
       it('should set args for the on-deck request', function() {
-        expect(this.transport.onDeckRequestArgs).toEqual(['bad', $.noop]);
+        expect(this.transport.onDeckRequestArgs)
+        .toEqual(['http://example.com?q=bad', $.noop]);
       });
     });