Add spec for removing duplicate datastreams

Multiple data files for Campbell Scientific may have the same
datastreams defined, so they should be re-used and not duplicated.

Author: openfirmware

lib/transloader/campbell_scientific/station.rb

@@ -106,8 +106,11 @@ def download_metadata(override_metadata: {}, overwrite: false)
         end
       end
 
-      # TODO: Reduce datastreams to unique entries, as multiple data 
-      # files *may* share the same properties
+      # Reduce datastreams to unique entries, as multiple data files 
+      # *may* share the same properties
+      datastreams.uniq! do |datastream|
+        datastream[:name]
+      end
 
       logger.warn "Latitude and Longitude unavailable from metadata."
       logger.warn "These values must be manually added to the station metadata file."

spec/transloader/campbell_scientific_station_spec.rb

@@ -72,8 +72,21 @@
       end
     end
 
-    # TODO: Removes duplicate datastreams parsed from the headers of 
-    # multiple data files
+    it "removes duplicate datastreams for multiple data files" do
+      VCR.use_cassette("campbell_scientific/station_two") do
+        @provider = Transloader::CampbellScientificProvider.new($cache_dir, @http_client)
+        @station = @provider.get_station(
+          station_id: "606830",
+          data_urls: [
+            "http://dataservices.campbellsci.ca/sbd/606830/data/CBAY_MET_1HR.dat",
+            "http://dataservices.campbellsci.ca/sbd/606830/data/CBAY_MET_1HR-Archive_2018-08-05%2015-04-05.dat"
+          ]
+        )
+        @station.download_metadata
+
+        expect(@station.metadata[:datastreams].length).to eq(22)
+      end
+    end
   end
 
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