feat(Object): add AV.Object.fetchAll (#327)

* fix(Request): remove duplicated getServerURLPromise resolving

* feat(Object): add AV.Object.fetchAll

Author: leeyeh

src/object.js

@@ -115,6 +115,42 @@ module.exports = function(AV) {
     return AV.Object._deepSaveAsync(list, null, options)._thenRunCallbacks(options);
   };
 
+  /**
+   * Fetch the given list of AV.Object.
+   * 
+   * @param {AV.Object[]} objects A list of <code>AV.Object</code>
+   * @param {Object} options
+   * @param {String} options.sessionToken specify user's session, used in LeanEngine.
+   * @return {Promise.<AV.Object[]>} The given list of <code>AV.Object</code>, updated
+   */
+
+  AV.Object.fetchAll = (objects, options) =>
+    AV.Promise.as().then(() =>
+      AVRequest('batch', null, null, 'POST', {
+        requests: _.map(objects, object => {
+          if (!object.className) throw new Error('object must have className to fetch');
+          if (!object.id) throw new Error('object must have id to fetch');
+          if (object.dirty()) throw new Error('object is modified but not saved');
+          return {
+            method: 'GET',
+            path: `/1.1/classes/${object.className}/${object.id}`,
+          };
+        }),
+      }, options && options.sessionToken)
+    ).then(function(response) {
+      _.forEach(objects, function(object, i) {
+        if (response[i].success) {
+          object._finishFetch(
+            object.parse(response[i].success));
+        } else {
+          const error = new Error(response[i].error.error);
+          error.code = response[i].error.code;
+          throw error;
+        }
+      });
+      return objects;
+    });
+  
   // Attach all inheritable methods to the AV.Object prototype.
   _.extend(AV.Object.prototype, AV.Events,
            /** @lends AV.Object.prototype */ {
@@ -574,7 +610,7 @@ module.exports = function(AV) {
      * @param {Object} options A set of Backbone-like options for the set.
      *     The only supported options are <code>silent</code>,
      *     <code>error</code>, and <code>promise</code>.
-     * @return {Boolean} true if the set succeeded.
+     * @return {AV.Object} self if succeeded, false if the value is not valid.
      * @see AV.Object#validate
      * @see AVError
      */
@@ -1258,7 +1294,7 @@ module.exports = function(AV) {
    };
    /**
     * Delete objects in batch.The objects className must be the same.
-    * @param {Array} The ParseObject array to be deleted.
+    * @param {Array} The <code>AV.Object</code> array to be deleted.
     * @param {Object} options Standard options object with success and error
     *     callbacks.
     * @return {AV.Promise} A promise that is fulfilled when the save

src/request.js

@@ -256,7 +256,6 @@ const setServerUrlByRegion = (region = 'cn') => {
     Cache.getAsync('APIServerURL').then((serverURL) => {
       if (serverURL) {
         setServerUrl(serverURL);
-        getServerURLPromise.resolve();
       } else {
         return refreshServerUrlByRouter();
       }

test/object.js

@@ -142,6 +142,51 @@ describe('Objects', function(){
     });
   });
 
+  describe('Fetching Objects', () => {
+    it('fetch', () => 
+      AV.Object.createWithoutData('GameScore', gameScore.id).fetch().then(score => {
+        expect(score.get('score')).to.be.a('number');
+        expect(score.createdAt).to.be.a(Date);
+        expect(score.id).to.be.eql(gameScore.id);
+      })
+    );
+    it('fetchAll', () => 
+      AV.Object.fetchAll([
+        AV.Object.createWithoutData('GameScore', gameScore.id),
+        AV.Object.createWithoutData('GameScore', gameScore.id),
+      ]).then(([score1, score2]) => {
+        expect(score1.get('score')).to.be.a('number');
+        expect(score1.createdAt).to.be.a(Date);
+        expect(score1.id).to.be.eql(gameScore.id);
+        expect(score2.get('score')).to.be.a('number');
+        expect(score2.createdAt).to.be.a(Date);
+        expect(score2.id).to.be.eql(gameScore.id);
+      })
+    );
+    it('fetchAll with non-existed Class should fail', (done) => 
+      AV.Object.fetchAll([
+        AV.Object.createWithoutData('GameScore', gameScore.id),
+        AV.Object.createWithoutData('FakeClass', gameScore.id),
+      ]).then(function() {
+        done(new Error(`should be rejected`));
+      }, function(err) {
+        expect(err).to.be.an(Error);
+        done();
+      })
+    );
+    it('fetchAll with dirty objet should fail', (done) => 
+      AV.Object.fetchAll([
+        AV.Object.createWithoutData('GameScore', gameScore.id),
+        new GameScore(),
+      ]).then(function() {
+        done(new Error(`should be rejected`));
+      }, function(err) {
+        expect(err).to.be.an(Error);
+        done();
+      })
+    );
+  });
+
   describe("Deleting Objects",function(){
     it("should delete cheatMode",function(done){
       gameScore.unset("cheatMode");