Rename `RouteWayCostJSONSerializer` to `RouteWayCostUnitConverter`

Because we need to pass a Ruby hash to Rabl instead of a JSON string,
get rid of our serialiser and instead turn it into a function that just
converts the distance & time units.

Fix a bug in the test that had the `'1-2'` key as a symbol instead of a
string which was caused by a copy-paste from JSON and not being thorough
enough in search-and-replace.

Refs #6203

4 files changed, 32 insertions, 36 deletions

diff --git a/app/views/routes/costs.rabl b/app/views/routes/costs.rabl
index 2c336fb51..1a1b14898 100644
--- a/app/views/routes/costs.rabl
+++ b/app/views/routes/costs.rabl
@@ -1,4 +1,4 @@
 object @route
 node :costs do
-  RouteWayCostJSONSerializer.dump(@route.costs)
+  RouteWayCostUnitConverter.convert(@route.costs)
 end
diff --git a/lib/route_way_cost_json_serializer.rb b/lib/route_way_cost_unit_converter.rb
index 20b3d6ee2..1aebbbb14 100644
--- a/lib/route_way_cost_json_serializer.rb
+++ b/lib/route_way_cost_unit_converter.rb
@@ -1,13 +1,11 @@
-class RouteWayCostJSONSerializer
-  def self.dump(way_costs)
+class RouteWayCostUnitConverter
+  def self.convert(way_costs)
     return if way_costs.nil?
 
     way_costs.each do |_, costs|
       costs['distance'] = self.meters_to_kilometers(costs['distance'])
       costs['time'] = self.seconds_to_minutes(costs['time'])
     end
-
-    JSON.dump(way_costs)
   end
 
   private
diff --git a/spec/lib/route_way_cost_json_serializer_spec.rb b/spec/lib/route_way_cost_json_serializer_spec.rb
deleted file mode 100644
index 52cb21afc..000000000
--- a/spec/lib/route_way_cost_json_serializer_spec.rb
+++ /dev/null
@@ -1,31 +0,0 @@
-RSpec.describe RouteWayCostJSONSerializer do
-  describe ".dump" do
-    it "converts distance from meters to km and time from seconds to minutes" do
-      costs = {
-        '1-2': {
-          'distance' => 35223,
-          'time' => 5604
-        },
-        '94435-97513' => {
-          'distance' => 35919,
-          'time' => 6174
-        }
-      }
-
-      expect(
-        RouteWayCostJSONSerializer.dump(costs)
-      ).to eq(<<-JSON.delete(" \n"))
-        {
-          "1-2": {
-            "distance": 35.223,
-            "time": 93
-          },
-          "94435-97513": {
-            "distance": 35.919,
-            "time": 102
-          }
-        }
-      JSON
-    end
-  end
-end
diff --git a/spec/lib/route_way_cost_unit_converter_spec.rb b/spec/lib/route_way_cost_unit_converter_spec.rb
new file mode 100644
index 000000000..33fb1d9aa
--- /dev/null
+++ b/spec/lib/route_way_cost_unit_converter_spec.rb
@@ -0,0 +1,29 @@
+RSpec.describe RouteWayCostUnitConverter do
+  describe ".convert" do
+    it "converts distance from meters to km and time from seconds to minutes" do
+      costs = {
+        '1-2' => {
+          'distance' => 35223,
+          'time' => 5604
+        },
+        '94435-97513' => {
+          'distance' => 35919,
+          'time' => 6174
+        }
+      }
+
+      expect(
+        RouteWayCostUnitConverter.convert(costs)
+      ).to eq({
+        '1-2' => {
+          'distance' => 35.223,
+          'time' => 93
+        },
+        '94435-97513' => {
+          'distance' => 35.919,
+          'time' => 102
+        }
+      })
+    end
+  end
+end