test error handling in fetching process

lib/fiatrateservice.js

@@ -68,11 +68,13 @@ FiatRateService.prototype._fetch = function(cb) {
   async.each(self.providers, function(provider, next) {
     self._retrieve(provider, function(err, res) {
       if (err) {
-        log.warn(err);
+        log.warn('Error retrieving data for ' + provider.name, err);
         return next();
       }
       self.storage.storeFiatRate(provider.name, res, function(err) {
-        if (err) log.warn(err);
+        if (err) {
+          log.warn('Error storing data for ' + provider.name, err);
+        }
         return next();
       });
     });
@@ -88,14 +90,13 @@ FiatRateService.prototype._retrieve = function(provider, cb) {
     json: true,
   }, function(err, res, body) {
     if (err || !body) {
-      log.warn('Error fetching data for ' + provider.name, err);
       return cb(err);
     }
 
     log.debug('Data for ' + provider.name + ' fetched successfully');
 
     if (!provider.parseFn) {
-      return cb('No parse function for provider ' + provider.name);
+      return cb(new Error('No parse function for provider ' + provider.name));
     }
     var rates = provider.parseFn(body);
 

test/integration/fiatrateservice.js

@@ -209,5 +209,39 @@ describe('Fiat rate service', function() {
         });
       });
     });
+
+    it('should not stop when failing to fetch provider', function(done) {
+      var clock = sinon.useFakeTimers(100, 'Date');
+      var bitstamp = {
+        last: 120.00,
+      };
+      request.get.withArgs({
+        url: 'https://bitpay.com/api/rates/',
+        json: true
+      }).yields('dummy error', null, null);
+      request.get.withArgs({
+        url: 'https://www.bitstamp.net/api/ticker/',
+        json: true
+      }).yields(null, null, bitstamp);
+
+      service._fetch(function(err) {
+        should.not.exist(err);
+        service.getRate('USD', {}, function(err, res) {
+          should.not.exist(err);
+          res.ts.should.equal(100);
+          should.not.exist(res.rate)
+          should.not.exist(res.fetchedOn)
+          service.getRate('USD', {
+            provider: 'Bitstamp'
+          }, function(err, res) {
+            should.not.exist(err);
+            res.fetchedOn.should.equal(100);
+            res.rate.should.equal(120.00);
+            clock.restore();
+            done();
+          });
+        });
+      });
+    });
   });
 });