spiders(kosovo): check for empty packages

kingfisher_scrapy/spiders/kosovo.py

@@ -1,6 +1,6 @@
 from datetime import timedelta
 
-from kingfisher_scrapy.util import parameters
+from kingfisher_scrapy.util import parameters, handle_http_error
 from kingfisher_scrapy.base_spider import SimpleSpider
 
 
@@ -27,13 +27,19 @@ class Kosovo(SimpleSpider):
     data_type = 'release_package'
 
     def start_requests(self):
-        # The API is slow even with short periods, so we request one day at a time
+        # The API is slow even with short periods, so we request one day at a time.
         delta = self.until_date - self.from_date
         for days in reversed(range(delta.days + 1)):
             start = self.from_date + timedelta(days=days-1)
             end = self.from_date + timedelta(days=days)
-            yield self.build_request(
-                    'https://ocdskrpp.rks-gov.net/krppapi/tenderrelease?endDateFrom='
-                    f'{start.strftime("%Y-%m-%d")}&endDateEnd={end.strftime("%Y-%m-%d")}',
-                    formatter=parameters('endDateFrom', 'endDateEnd')
-            )
+            url = f'https://ocdskrpp.rks-gov.net/krppapi/tenderrelease?endDateFrom=' \
+                  f'{start.strftime("%Y-%m-%d")}&endDateEnd={end.strftime("%Y-%m-%d")}'
+
+            yield self.build_request(url, formatter=parameters('endDateFrom', 'endDateEnd'))
+
+    @handle_http_error
+    def parse(self, response):
+        data = response.json()
+        # The API returns a release package with an empty releases array if no releases were found.
+        if data['releases']:
+            yield self.build_file_from_response(response, data_type=self.data_type)