RouteWayCostUnitConverter: Round kilometres to 2 decimal places

The JavaScript validation doesn't pass if we have more than two decimal
places (I think because it uses a number field step value of 0.01).
Round the values to allow them to pass frontend validation.

Refs #6203

2 files changed, 6 insertions, 4 deletions

diff --git a/lib/route_way_cost_unit_converter.rb b/lib/route_way_cost_unit_converter.rb
index 1aebbbb14..979e92b0c 100644
--- a/lib/route_way_cost_unit_converter.rb
+++ b/lib/route_way_cost_unit_converter.rb
@@ -10,8 +10,9 @@ class RouteWayCostUnitConverter
 
   private
 
+  # Round to 2 decimal places to appease JavaScript validation
   def self.meters_to_kilometers(num)
-    num / 1000.0
+    (num / 1000.0).round(2)
   end
 
   def self.seconds_to_minutes(num)
diff --git a/spec/lib/route_way_cost_unit_converter_spec.rb b/spec/lib/route_way_cost_unit_converter_spec.rb
index 33fb1d9aa..624ef5052 100644
--- a/spec/lib/route_way_cost_unit_converter_spec.rb
+++ b/spec/lib/route_way_cost_unit_converter_spec.rb
@@ -1,6 +1,7 @@
 RSpec.describe RouteWayCostUnitConverter do
   describe ".convert" do
-    it "converts distance from meters to km and time from seconds to minutes" do
+    it "converts distance from meters to km and time from seconds to minutes " \
+      "and rounds to two decimal places" do
       costs = {
         '1-2' => {
           'distance' => 35223,
@@ -16,11 +17,11 @@ RSpec.describe RouteWayCostUnitConverter do
         RouteWayCostUnitConverter.convert(costs)
       ).to eq({
         '1-2' => {
-          'distance' => 35.223,
+          'distance' => 35.22,
           'time' => 93
         },
         '94435-97513' => {
-          'distance' => 35.919,
+          'distance' => 35.92,
           'time' => 102
         }
       })